editors/sed.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * sed.c - very minimalist version of sed
   4  *
   5  * Copyright (C) 1999,2000,2001 by Lineo, inc. and Mark Whitley
   6  * Copyright (C) 1999,2000,2001 by Mark Whitley <markw@codepoet.org>
   7  * Copyright (C) 2002  Matt Kraai
   8  * Copyright (C) 2003 by Glenn McGrath
   9  * Copyright (C) 2003,2004 by Rob Landley <rob@landley.net>
  10  *
  11  * MAINTAINER: Rob Landley <rob@landley.net>
  12  *
  13  * Licensed under GPLv2, see file LICENSE in this source tree.
  14  */
  15
  16 /* Code overview.
  17  *
  18  * Files are laid out to avoid unnecessary function declarations.  So for
  19  * example, every function add_cmd calls occurs before add_cmd in this file.
  20  *
  21  * add_cmd() is called on each line of sed command text (from a file or from
  22  * the command line).  It calls get_address() and parse_cmd_args().  The
  23  * resulting sed_cmd_t structures are appended to a linked list
  24  * (G.sed_cmd_head/G.sed_cmd_tail).
  25  *
  26  * process_files() does actual sedding, reading data lines from each input FILE*
  27  * (which could be stdin) and applying the sed command list (sed_cmd_head) to
  28  * each of the resulting lines.
  29  *
  30  * sed_main() is where external code calls into this, with a command line.
  31  */
  32
  33 /* Supported features and commands in this version of sed:
  34  *
  35  * - comments ('#')
  36  * - address matching: num|/matchstr/[,num|/matchstr/|$]command
  37  * - commands: (p)rint, (d)elete, (s)ubstitue (with g & I flags)
  38  * - edit commands: (a)ppend, (i)nsert, (c)hange
  39  * - file commands: (r)ead
  40  * - backreferences in substitution expressions (\0, \1, \2...\9)
  41  * - grouped commands: {cmd1;cmd2}
  42  * - transliteration (y/source-chars/dest-chars/)
  43  * - pattern space hold space storing / swapping (g, h, x)
  44  * - labels / branching (: label, b, t, T)
  45  *
  46  * (Note: Specifying an address (range) to match is *optional*; commands
  47  * default to the whole pattern space if no specific address match was
  48  * requested.)
  49  *
  50  * Todo:
  51  * - Create a wrapper around regex to make libc's regex conform with sed
  52  *
  53  * Reference
  54  * http://www.opengroup.org/onlinepubs/007904975/utilities/sed.html
  55  * http://pubs.opengroup.org/onlinepubs/9699919799/utilities/sed.html
  56  * http://sed.sourceforge.net/sedfaq3.html
  57  */
  58
  59 //config:config SED
  60 //config:       bool "sed"
  61 //config:       default y
  62 //config:       help
  63 //config:         sed is used to perform text transformations on a file
  64 //config:         or input from a pipeline.
  65
  66 //kbuild:lib-$(CONFIG_SED) += sed.o
  67
  68 //applet:IF_SED(APPLET(sed, BB_DIR_BIN, BB_SUID_DROP))
  69
  70 //usage:#define sed_trivial_usage
  71 //usage:       "[-inrE] [-f FILE]... [-e CMD]... [FILE]...\n"
  72 //usage:       "or: sed [-inrE] CMD [FILE]..."
  73 //usage:#define sed_full_usage "\n\n"
  74 //usage:       "        -e CMD  Add CMD to sed commands to be executed"
  75 //usage:     "\n        -f FILE Add FILE contents to sed commands to be executed"
  76 //usage:     "\n        -i[SFX] Edit files in-place (otherwise sends to stdout)"
  77 //usage:     "\n                Optionally back files up, appending SFX"
  78 //usage:     "\n        -n      Suppress automatic printing of pattern space"
  79 //usage:     "\n        -r,-E   Use extended regex syntax"
  80 //usage:     "\n"
  81 //usage:     "\nIf no -e or -f, the first non-option argument is the sed command string."
  82 //usage:     "\nRemaining arguments are input files (stdin if none)."
  83 //usage:
  84 //usage:#define sed_example_usage
  85 //usage:       "$ echo \"foo\" | sed -e 's/f[a-zA-Z]o/bar/g'\n"
  86 //usage:       "bar\n"
  87
  88 #include "libbb.h"
  89 #include "common_bufsiz.h"
  90 #include "xregex.h"
  91
  92 #if 0
  93 # define dbg(...) bb_error_msg(__VA_ARGS__)
  94 #else
  95 # define dbg(...) ((void)0)
  96 #endif
  97
  98
  99 enum {
 100         OPT_in_place = 1 << 0,
 101 };
 102
 103 /* Each sed command turns into one of these structures. */
 104 typedef struct sed_cmd_s {
 105         /* Ordered by alignment requirements: currently 36 bytes on x86 */
 106         struct sed_cmd_s *next; /* Next command (linked list, NULL terminated) */
 107
 108         /* address storage */
 109         regex_t *beg_match;     /* sed -e '/match/cmd' */
 110         regex_t *end_match;     /* sed -e '/match/,/end_match/cmd' */
 111         regex_t *sub_match;     /* For 's/sub_match/string/' */
 112         int beg_line;           /* 'sed 1p'   0 == apply commands to all lines */
 113         int beg_line_orig;      /* copy of the above, needed for -i */
 114         int end_line;           /* 'sed 1,3p' 0 == one line only. -1 = last line ($). -2-N = +N */
 115         int end_line_orig;
 116
 117         FILE *sw_file;          /* File (sw) command writes to, NULL for none. */
 118         char *string;           /* Data string for (saicytb) commands. */
 119
 120         unsigned which_match;   /* (s) Which match to replace (0 for all) */
 121
 122         /* Bitfields (gcc won't group them if we don't) */
 123         unsigned invert:1;      /* the '!' after the address */
 124         unsigned in_match:1;    /* Next line also included in match? */
 125         unsigned sub_p:1;       /* (s) print option */
 126
 127         char sw_last_char;      /* Last line written by (sw) had no '\n' */
 128
 129         /* GENERAL FIELDS */
 130         char cmd;               /* The command char: abcdDgGhHilnNpPqrstwxy:={} */
 131 } sed_cmd_t;
 132
 133 static const char semicolon_whitespace[] ALIGN1 = "; \n\r\t\v";
 134
 135 struct globals {
 136         /* options */
 137         int be_quiet, regex_type;
 138
 139         FILE *nonstdout;
 140         char *outname, *hold_space;
 141         smallint exitcode;
 142
 143         /* list of input files */
 144         int current_input_file, last_input_file;
 145         char **input_file_list;
 146         FILE *current_fp;
 147
 148         regmatch_t regmatch[10];
 149         regex_t *previous_regex_ptr;
 150
 151         /* linked list of sed commands */
 152         sed_cmd_t *sed_cmd_head, **sed_cmd_tail;
 153
 154         /* linked list of append lines */
 155         llist_t *append_head;
 156
 157         char *add_cmd_line;
 158
 159         struct pipeline {
 160                 char *buf;  /* Space to hold string */
 161                 int idx;    /* Space used */
 162                 int len;    /* Space allocated */
 163         } pipeline;
 164 } FIX_ALIASING;
 165 #define G (*(struct globals*)bb_common_bufsiz1)
 166 #define INIT_G() do { \
 167         setup_common_bufsiz(); \
 168         BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
 169         G.sed_cmd_tail = &G.sed_cmd_head; \
 170 } while (0)
 171
 172
 173 #if ENABLE_FEATURE_CLEAN_UP
 174 static void sed_free_and_close_stuff(void)
 175 {
 176         sed_cmd_t *sed_cmd = G.sed_cmd_head;
 177
 178         llist_free(G.append_head, free);
 179
 180         while (sed_cmd) {
 181                 sed_cmd_t *sed_cmd_next = sed_cmd->next;
 182
 183                 if (sed_cmd->sw_file)
 184                         fclose(sed_cmd->sw_file);
 185
 186                 if (sed_cmd->beg_match) {
 187                         regfree(sed_cmd->beg_match);
 188                         free(sed_cmd->beg_match);
 189                 }
 190                 if (sed_cmd->end_match) {
 191                         regfree(sed_cmd->end_match);
 192                         free(sed_cmd->end_match);
 193                 }
 194                 if (sed_cmd->sub_match) {
 195                         regfree(sed_cmd->sub_match);
 196                         free(sed_cmd->sub_match);
 197                 }
 198                 free(sed_cmd->string);
 199                 free(sed_cmd);
 200                 sed_cmd = sed_cmd_next;
 201         }
 202
 203         free(G.hold_space);
 204
 205         if (G.current_fp)
 206                 fclose(G.current_fp);
 207 }
 208 #else
 209 void sed_free_and_close_stuff(void);
 210 #endif
 211
 212 /* If something bad happens during -i operation, delete temp file */
 213
 214 static void cleanup_outname(void)
 215 {
 216         if (G.outname) unlink(G.outname);
 217 }
 218
 219 /* strcpy, replacing "\from" with 'to'. If to is NUL, replacing "\any" with 'any' */
 220
 221 static unsigned parse_escapes(char *dest, const char *string, int len, char from, char to)
 222 {
 223         char *d = dest;
 224         int i = 0;
 225
 226         if (len == -1)
 227                 len = strlen(string);
 228
 229         while (i < len) {
 230                 if (string[i] == '\\') {
 231                         if (!to || string[i+1] == from) {
 232                                 if ((*d = to ? to : string[i+1]) == '\0')
 233                                         return d - dest;
 234                                 i += 2;
 235                                 d++;
 236                                 continue;
 237                         }
 238                         i++; /* skip backslash in string[] */
 239                         *d++ = '\\';
 240                         /* fall through: copy next char verbatim */
 241                 }
 242                 if ((*d = string[i++]) == '\0')
 243                         return d - dest;
 244                 d++;
 245         }
 246         *d = '\0';
 247         return d - dest;
 248 }
 249
 250 static char *copy_parsing_escapes(const char *string, int len)
 251 {
 252         const char *s;
 253         char *dest = xmalloc(len + 1);
 254
 255         /* sed recognizes \n */
 256         /* GNU sed also recognizes \t and \r */
 257         for (s = "\nn\tt\rr"; *s; s += 2) {
 258                 len = parse_escapes(dest, string, len, s[1], s[0]);
 259                 string = dest;
 260         }
 261         return dest;
 262 }
 263
 264
 265 /*
 266  * index_of_next_unescaped_regexp_delim - walks left to right through a string
 267  * beginning at a specified index and returns the index of the next regular
 268  * expression delimiter (typically a forward slash ('/')) not preceded by
 269  * a backslash ('\').  A negative delimiter disables square bracket checking.
 270  */
 271 static int index_of_next_unescaped_regexp_delim(int delimiter, const char *str)
 272 {
 273         int bracket = -1;
 274         int escaped = 0;
 275         int idx = 0;
 276         char ch;
 277
 278         if (delimiter < 0) {
 279                 bracket--;
 280                 delimiter = -delimiter;
 281         }
 282
 283         for (; (ch = str[idx]) != '\0'; idx++) {
 284                 if (bracket >= 0) {
 285                         if (ch == ']'
 286                          && !(bracket == idx - 1 || (bracket == idx - 2 && str[idx - 1] == '^'))
 287                         ) {
 288                                 bracket = -1;
 289                         }
 290                 } else if (escaped)
 291                         escaped = 0;
 292                 else if (ch == '\\')
 293                         escaped = 1;
 294                 else if (bracket == -1 && ch == '[')
 295                         bracket = idx;
 296                 else if (ch == delimiter)
 297                         return idx;
 298         }
 299
 300         /* if we make it to here, we've hit the end of the string */
 301         bb_error_msg_and_die("unmatched '%c'", delimiter);
 302 }
 303
 304 /*
 305  *  Returns the index of the third delimiter
 306  */
 307 static int parse_regex_delim(const char *cmdstr, char **match, char **replace)
 308 {
 309         const char *cmdstr_ptr = cmdstr;
 310         unsigned char delimiter;
 311         int idx = 0;
 312
 313         /* verify that the 's' or 'y' is followed by something.  That something
 314          * (typically a 'slash') is now our regexp delimiter... */
 315         if (*cmdstr == '\0')
 316                 bb_error_msg_and_die("bad format in substitution expression");
 317         delimiter = *cmdstr_ptr++;
 318
 319         /* save the match string */
 320         idx = index_of_next_unescaped_regexp_delim(delimiter, cmdstr_ptr);
 321         *match = copy_parsing_escapes(cmdstr_ptr, idx);
 322
 323         /* save the replacement string */
 324         cmdstr_ptr += idx + 1;
 325         idx = index_of_next_unescaped_regexp_delim(- (int)delimiter, cmdstr_ptr);
 326         *replace = copy_parsing_escapes(cmdstr_ptr, idx);
 327
 328         return ((cmdstr_ptr - cmdstr) + idx);
 329 }
 330
 331 /*
 332  * returns the index in the string just past where the address ends.
 333  */
 334 static int get_address(const char *my_str, int *linenum, regex_t ** regex)
 335 {
 336         const char *pos = my_str;
 337
 338         if (isdigit(*my_str)) {
 339                 *linenum = strtol(my_str, (char**)&pos, 10);
 340                 /* endstr shouldnt ever equal NULL */
 341         } else if (*my_str == '$') {
 342                 *linenum = -1;
 343                 pos++;
 344         } else if (*my_str == '/' || *my_str == '\\') {
 345                 int next;
 346                 char delimiter;
 347                 char *temp;
 348
 349                 delimiter = '/';
 350                 if (*my_str == '\\')
 351                         delimiter = *++pos;
 352                 next = index_of_next_unescaped_regexp_delim(delimiter, ++pos);
 353                 temp = copy_parsing_escapes(pos, next);
 354                 *regex = xzalloc(sizeof(regex_t));
 355                 xregcomp(*regex, temp, G.regex_type);
 356                 free(temp);
 357                 /* Move position to next character after last delimiter */
 358                 pos += (next+1);
 359         }
 360         return pos - my_str;
 361 }
 362
 363 /* Grab a filename.  Whitespace at start is skipped, then goes to EOL. */
 364 static int parse_file_cmd(/*sed_cmd_t *sed_cmd,*/ const char *filecmdstr, char **retval)
 365 {
 366         int start = 0, idx, hack = 0;
 367
 368         /* Skip whitespace, then grab filename to end of line */
 369         while (isspace(filecmdstr[start]))
 370                 start++;
 371         idx = start;
 372         while (filecmdstr[idx] && filecmdstr[idx] != '\n')
 373                 idx++;
 374
 375         /* If lines glued together, put backslash back. */
 376         if (filecmdstr[idx] == '\n')
 377                 hack = 1;
 378         if (idx == start)
 379                 bb_error_msg_and_die("empty filename");
 380         *retval = xstrndup(filecmdstr+start, idx-start+hack+1);
 381         if (hack)
 382                 (*retval)[idx] = '\\';
 383
 384         return idx;
 385 }
 386
 387 static int parse_subst_cmd(sed_cmd_t *sed_cmd, const char *substr)
 388 {
 389         int cflags = G.regex_type;
 390         char *match;
 391         int idx;
 392
 393         /*
 394          * A substitution command should look something like this:
 395          *    s/match/replace/ #giIpw
 396          *    ||     |        |||
 397          *    mandatory       optional
 398          */
 399         idx = parse_regex_delim(substr, &match, &sed_cmd->string);
 400
 401         /* determine the number of back references in the match string */
 402         /* Note: we compute this here rather than in the do_subst_command()
 403          * function to save processor time, at the expense of a little more memory
 404          * (4 bits) per sed_cmd */
 405
 406         /* process the flags */
 407
 408         sed_cmd->which_match = 1;
 409         dbg("s flags:'%s'", substr + idx + 1);
 410         while (substr[++idx]) {
 411                 dbg("s flag:'%c'", substr[idx]);
 412                 /* Parse match number */
 413                 if (isdigit(substr[idx])) {
 414                         if (match[0] != '^') {
 415                                 /* Match 0 treated as all, multiple matches we take the last one. */
 416                                 const char *pos = substr + idx;
 417 /* FIXME: error check? */
 418                                 sed_cmd->which_match = (unsigned)strtol(substr+idx, (char**) &pos, 10);
 419                                 idx = pos - substr - 1;
 420                         }
 421                         continue;
 422                 }
 423                 /* Skip spaces */
 424                 if (isspace(substr[idx]))
 425                         continue;
 426
 427                 switch (substr[idx]) {
 428                 /* Replace all occurrences */
 429                 case 'g':
 430                         if (match[0] != '^')
 431                                 sed_cmd->which_match = 0;
 432                         break;
 433                 /* Print pattern space */
 434                 case 'p':
 435                         sed_cmd->sub_p = 1;
 436                         break;
 437                 /* Write to file */
 438                 case 'w':
 439                 {
 440                         char *fname;
 441                         idx += parse_file_cmd(/*sed_cmd,*/ substr+idx+1, &fname);
 442                         sed_cmd->sw_file = xfopen_for_write(fname);
 443                         sed_cmd->sw_last_char = '\n';
 444                         free(fname);
 445                         break;
 446                 }
 447                 /* Ignore case (gnu exension) */
 448                 case 'i':
 449                 case 'I':
 450                         cflags |= REG_ICASE;
 451                         break;
 452                 /* Comment */
 453                 case '#':
 454                         // while (substr[++idx]) continue;
 455                         idx += strlen(substr + idx); // same
 456                         /* Fall through */
 457                 /* End of command */
 458                 case ';':
 459                 case '}':
 460                         goto out;
 461                 default:
 462                         dbg("s bad flags:'%s'", substr + idx);
 463                         bb_error_msg_and_die("bad option in substitution expression");
 464                 }
 465         }
 466  out:
 467         /* compile the match string into a regex */
 468         if (*match != '\0') {
 469                 /* If match is empty, we use last regex used at runtime */
 470                 sed_cmd->sub_match = xzalloc(sizeof(regex_t));
 471                 dbg("xregcomp('%s',%x)", match, cflags);
 472                 xregcomp(sed_cmd->sub_match, match, cflags);
 473                 dbg("regcomp ok");
 474         }
 475         free(match);
 476
 477         return idx;
 478 }
 479
 480 /*
 481  *  Process the commands arguments
 482  */
 483 static const char *parse_cmd_args(sed_cmd_t *sed_cmd, const char *cmdstr)
 484 {
 485         static const char cmd_letters[] ALIGN1 = "saicrw:btTydDgGhHlnNpPqx={}";
 486         enum {
 487                 IDX_s = 0,
 488                 IDX_a,
 489                 IDX_i,
 490                 IDX_c,
 491                 IDX_r,
 492                 IDX_w,
 493                 IDX_colon,
 494                 IDX_b,
 495                 IDX_t,
 496                 IDX_T,
 497                 IDX_y,
 498                 IDX_d,
 499                 IDX_D,
 500                 IDX_g,
 501                 IDX_G,
 502                 IDX_h,
 503                 IDX_H,
 504                 IDX_l,
 505                 IDX_n,
 506                 IDX_N,
 507                 IDX_p,
 508                 IDX_P,
 509                 IDX_q,
 510                 IDX_x,
 511                 IDX_equal,
 512                 IDX_lbrace,
 513                 IDX_rbrace,
 514                 IDX_nul
 515         };
 516         unsigned idx;
 517
 518         BUILD_BUG_ON(sizeof(cmd_letters)-1 != IDX_nul);
 519
 520         idx = strchrnul(cmd_letters, sed_cmd->cmd) - cmd_letters;
 521
 522         /* handle (s)ubstitution command */
 523         if (idx == IDX_s) {
 524                 cmdstr += parse_subst_cmd(sed_cmd, cmdstr);
 525         }
 526         /* handle edit cmds: (a)ppend, (i)nsert, and (c)hange */
 527         else if (idx <= IDX_c) { /* a,i,c */
 528                 unsigned len;
 529
 530                 if (idx < IDX_c) { /* a,i */
 531                         if (sed_cmd->end_line || sed_cmd->end_match)
 532                                 bb_error_msg_and_die("command '%c' uses only one address", sed_cmd->cmd);
 533                 }
 534                 for (;;) {
 535                         if (*cmdstr == '\n' || *cmdstr == '\\') {
 536                                 cmdstr++;
 537                                 break;
 538                         }
 539                         if (!isspace(*cmdstr))
 540                                 break;
 541                         cmdstr++;
 542                 }
 543                 len = strlen(cmdstr);
 544                 sed_cmd->string = copy_parsing_escapes(cmdstr, len);
 545                 cmdstr += len;
 546                 /* "\anychar" -> "anychar" */
 547                 parse_escapes(sed_cmd->string, sed_cmd->string, -1, '\0', '\0');
 548         }
 549         /* handle file cmds: (r)ead */
 550         else if (idx <= IDX_w) { /* r,w */
 551                 if (idx < IDX_w) { /* r */
 552                         if (sed_cmd->end_line || sed_cmd->end_match)
 553                                 bb_error_msg_and_die("command '%c' uses only one address", sed_cmd->cmd);
 554                 }
 555                 cmdstr += parse_file_cmd(/*sed_cmd,*/ cmdstr, &sed_cmd->string);
 556                 if (sed_cmd->cmd == 'w') {
 557                         sed_cmd->sw_file = xfopen_for_write(sed_cmd->string);
 558                         sed_cmd->sw_last_char = '\n';
 559                 }
 560         }
 561         /* handle branch commands */
 562         else if (idx <= IDX_T) { /* :,b,t,T */
 563                 int length;
 564
 565                 cmdstr = skip_whitespace(cmdstr);
 566                 length = strcspn(cmdstr, semicolon_whitespace);
 567                 if (length) {
 568                         sed_cmd->string = xstrndup(cmdstr, length);
 569                         cmdstr += length;
 570                 }
 571         }
 572         /* translation command */
 573         else if (idx == IDX_y) {
 574                 char *match, *replace;
 575                 int i = cmdstr[0];
 576
 577                 cmdstr += parse_regex_delim(cmdstr, &match, &replace)+1;
 578                 /* \n already parsed, but \delimiter needs unescaping. */
 579                 parse_escapes(match,   match,   -1, i, i);
 580                 parse_escapes(replace, replace, -1, i, i);
 581
 582                 sed_cmd->string = xzalloc((strlen(match) + 1) * 2);
 583                 for (i = 0; match[i] && replace[i]; i++) {
 584                         sed_cmd->string[i*2] = match[i];
 585                         sed_cmd->string[i*2+1] = replace[i];
 586                 }
 587                 free(match);
 588                 free(replace);
 589         }
 590         /* if it wasnt a single-letter command that takes no arguments
 591          * then it must be an invalid command.
 592          */
 593         else if (idx >= IDX_nul) { /* not d,D,g,G,h,H,l,n,N,p,P,q,x,=,{,} */
 594                 bb_error_msg_and_die("unsupported command %c", sed_cmd->cmd);
 595         }
 596
 597         /* give back whatever's left over */
 598         return cmdstr;
 599 }
 600
 601
 602 /* Parse address+command sets, skipping comment lines. */
 603
 604 static void add_cmd(const char *cmdstr)
 605 {
 606         sed_cmd_t *sed_cmd;
 607         unsigned len, n;
 608
 609         /* Append this line to any unfinished line from last time. */
 610         if (G.add_cmd_line) {
 611                 char *tp = xasprintf("%s\n%s", G.add_cmd_line, cmdstr);
 612                 free(G.add_cmd_line);
 613                 cmdstr = G.add_cmd_line = tp;
 614         }
 615
 616         /* If this line ends with unescaped backslash, request next line. */
 617         n = len = strlen(cmdstr);
 618         while (n && cmdstr[n-1] == '\\')
 619                 n--;
 620         if ((len - n) & 1) { /* if odd number of trailing backslashes */
 621                 if (!G.add_cmd_line)
 622                         G.add_cmd_line = xstrdup(cmdstr);
 623                 G.add_cmd_line[len-1] = '\0';
 624                 return;
 625         }
 626
 627         /* Loop parsing all commands in this line. */
 628         while (*cmdstr) {
 629                 /* Skip leading whitespace and semicolons */
 630                 cmdstr += strspn(cmdstr, semicolon_whitespace);
 631
 632                 /* If no more commands, exit. */
 633                 if (!*cmdstr) break;
 634
 635                 /* if this is a comment, jump past it and keep going */
 636                 if (*cmdstr == '#') {
 637                         /* "#n" is the same as using -n on the command line */
 638                         if (cmdstr[1] == 'n')
 639                                 G.be_quiet++;
 640                         cmdstr = strpbrk(cmdstr, "\n\r");
 641                         if (!cmdstr) break;
 642                         continue;
 643                 }
 644
 645                 /* parse the command
 646                  * format is: [addr][,addr][!]cmd
 647                  *            |----||-----||-|
 648                  *            part1 part2  part3
 649                  */
 650
 651                 sed_cmd = xzalloc(sizeof(sed_cmd_t));
 652
 653                 /* first part (if present) is an address: either a '$', a number or a /regex/ */
 654                 cmdstr += get_address(cmdstr, &sed_cmd->beg_line, &sed_cmd->beg_match);
 655                 sed_cmd->beg_line_orig = sed_cmd->beg_line;
 656
 657                 /* second part (if present) will begin with a comma */
 658                 if (*cmdstr == ',') {
 659                         int idx;
 660
 661                         cmdstr++;
 662                         if (*cmdstr == '+' && isdigit(cmdstr[1])) {
 663                                 /* http://sed.sourceforge.net/sedfaq3.html#s3.3
 664                                  * Under GNU sed 3.02+, ssed, and sed15+, <address2>
 665                                  * may also be a notation of the form +num,
 666                                  * indicating the next num lines after <address1> is
 667                                  * matched.
 668                                  * GNU sed 4.2.1 accepts even "+" (meaning "+0").
 669                                  * We don't (we check for isdigit, see above), think
 670                                  * about the "+-3" case.
 671                                  */
 672                                 char *end;
 673                                 /* code is smaller compared to using &cmdstr here: */
 674                                 idx = strtol(cmdstr+1, &end, 10);
 675                                 sed_cmd->end_line = -2 - idx;
 676                                 cmdstr = end;
 677                         } else {
 678                                 idx = get_address(cmdstr, &sed_cmd->end_line, &sed_cmd->end_match);
 679                                 cmdstr += idx;
 680                                 idx--; /* if 0, trigger error check below */
 681                         }
 682                         if (idx < 0)
 683                                 bb_error_msg_and_die("no address after comma");
 684                         sed_cmd->end_line_orig = sed_cmd->end_line;
 685                 }
 686
 687                 /* skip whitespace before the command */
 688                 cmdstr = skip_whitespace(cmdstr);
 689
 690                 /* Check for inversion flag */
 691                 if (*cmdstr == '!') {
 692                         sed_cmd->invert = 1;
 693                         cmdstr++;
 694
 695                         /* skip whitespace before the command */
 696                         cmdstr = skip_whitespace(cmdstr);
 697                 }
 698
 699                 /* last part (mandatory) will be a command */
 700                 if (!*cmdstr)
 701                         bb_error_msg_and_die("missing command");
 702                 sed_cmd->cmd = *cmdstr++;
 703                 cmdstr = parse_cmd_args(sed_cmd, cmdstr);
 704
 705                 /* cmdstr now points past args.
 706                  * GNU sed requires a separator, if there are more commands,
 707                  * else it complains "char N: extra characters after command".
 708                  * Example: "sed 'p;d'". We also allow "sed 'pd'".
 709                  */
 710
 711                 /* Add the command to the command array */
 712                 *G.sed_cmd_tail = sed_cmd;
 713                 G.sed_cmd_tail = &sed_cmd->next;
 714         }
 715
 716         /* If we glued multiple lines together, free the memory. */
 717         free(G.add_cmd_line);
 718         G.add_cmd_line = NULL;
 719 }
 720
 721 /* Append to a string, reallocating memory as necessary. */
 722
 723 #define PIPE_GROW 64
 724
 725 static void pipe_putc(char c)
 726 {
 727         if (G.pipeline.idx == G.pipeline.len) {
 728                 G.pipeline.buf = xrealloc(G.pipeline.buf,
 729                                 G.pipeline.len + PIPE_GROW);
 730                 G.pipeline.len += PIPE_GROW;
 731         }
 732         G.pipeline.buf[G.pipeline.idx++] = c;
 733 }
 734
 735 static void do_subst_w_backrefs(char *line, char *replace)
 736 {
 737         int i, j;
 738
 739         /* go through the replacement string */
 740         for (i = 0; replace[i]; i++) {
 741                 /* if we find a backreference (\1, \2, etc.) print the backref'ed text */
 742                 if (replace[i] == '\\') {
 743                         unsigned backref = replace[++i] - '0';
 744                         if (backref <= 9) {
 745                                 /* print out the text held in G.regmatch[backref] */
 746                                 if (G.regmatch[backref].rm_so != -1) {
 747                                         j = G.regmatch[backref].rm_so;
 748                                         while (j < G.regmatch[backref].rm_eo)
 749                                                 pipe_putc(line[j++]);
 750                                 }
 751                                 continue;
 752                         }
 753                         /* I _think_ it is impossible to get '\' to be
 754                          * the last char in replace string. Thus we dont check
 755                          * for replace[i] == NUL. (counterexample anyone?) */
 756                         /* if we find a backslash escaped character, print the character */
 757                         pipe_putc(replace[i]);
 758                         continue;
 759                 }
 760                 /* if we find an unescaped '&' print out the whole matched text. */
 761                 if (replace[i] == '&') {
 762                         j = G.regmatch[0].rm_so;
 763                         while (j < G.regmatch[0].rm_eo)
 764                                 pipe_putc(line[j++]);
 765                         continue;
 766                 }
 767                 /* Otherwise just output the character. */
 768                 pipe_putc(replace[i]);
 769         }
 770 }
 771
 772 static int do_subst_command(sed_cmd_t *sed_cmd, char **line_p)
 773 {
 774         char *line = *line_p;
 775         unsigned match_count = 0;
 776         bool altered = 0;
 777         bool prev_match_empty = 1;
 778         bool tried_at_eol = 0;
 779         regex_t *current_regex;
 780
 781         current_regex = sed_cmd->sub_match;
 782         /* Handle empty regex. */
 783         if (!current_regex) {
 784                 current_regex = G.previous_regex_ptr;
 785                 if (!current_regex)
 786                         bb_error_msg_and_die("no previous regexp");
 787         }
 788         G.previous_regex_ptr = current_regex;
 789
 790         /* Find the first match */
 791         dbg("matching '%s'", line);
 792         if (REG_NOMATCH == regexec(current_regex, line, 10, G.regmatch, 0)) {
 793                 dbg("no match");
 794                 return 0;
 795         }
 796         dbg("match");
 797
 798         /* Initialize temporary output buffer. */
 799         G.pipeline.buf = xmalloc(PIPE_GROW);
 800         G.pipeline.len = PIPE_GROW;
 801         G.pipeline.idx = 0;
 802
 803         /* Now loop through, substituting for matches */
 804         do {
 805                 int start = G.regmatch[0].rm_so;
 806                 int end = G.regmatch[0].rm_eo;
 807                 int i;
 808
 809                 match_count++;
 810
 811                 /* If we aren't interested in this match, output old line to
 812                  * end of match and continue */
 813                 if (sed_cmd->which_match
 814                  && (sed_cmd->which_match != match_count)
 815                 ) {
 816                         for (i = 0; i < end; i++)
 817                                 pipe_putc(*line++);
 818                         /* Null match? Print one more char */
 819                         if (start == end && *line)
 820                                 pipe_putc(*line++);
 821                         goto next;
 822                 }
 823
 824                 /* Print everything before the match */
 825                 for (i = 0; i < start; i++)
 826                         pipe_putc(line[i]);
 827
 828                 /* Then print the substitution string,
 829                  * unless we just matched empty string after non-empty one.
 830                  * Example: string "cccd", pattern "c*", repl "R":
 831                  * result is "RdR", not "RRdR": first match "ccc",
 832                  * second is "" before "d", third is "" after "d".
 833                  * Second match is NOT replaced!
 834                  */
 835                 if (prev_match_empty || start != 0 || start != end) {
 836                         //dbg("%d %d %d", prev_match_empty, start, end);
 837                         dbg("inserting replacement at %d in '%s'", start, line);
 838                         do_subst_w_backrefs(line, sed_cmd->string);
 839                         /* Flag that something has changed */
 840                         altered = 1;
 841                 } else {
 842                         dbg("NOT inserting replacement at %d in '%s'", start, line);
 843                 }
 844
 845                 /* If matched string is empty (f.e. "c*" pattern),
 846                  * copy verbatim one char after it before attempting more matches
 847                  */
 848                 prev_match_empty = (start == end);
 849                 if (prev_match_empty) {
 850                         if (!line[end]) {
 851                                 tried_at_eol = 1;
 852                         } else {
 853                                 pipe_putc(line[end]);
 854                                 end++;
 855                         }
 856                 }
 857
 858                 /* Advance past the match */
 859                 dbg("line += %d", end);
 860                 line += end;
 861
 862                 /* if we're not doing this globally, get out now */
 863                 if (sed_cmd->which_match != 0)
 864                         break;
 865  next:
 866                 /* Exit if we are at EOL and already tried matching at it */
 867                 if (*line == '\0') {
 868                         if (tried_at_eol)
 869                                 break;
 870                         tried_at_eol = 1;
 871                 }
 872
 873 //maybe (end ? REG_NOTBOL : 0) instead of unconditional REG_NOTBOL?
 874         } while (regexec(current_regex, line, 10, G.regmatch, REG_NOTBOL) != REG_NOMATCH);
 875
 876         /* Copy rest of string into output pipeline */
 877         while (1) {
 878                 char c = *line++;
 879                 pipe_putc(c);
 880                 if (c == '\0')
 881                         break;
 882         }
 883
 884         free(*line_p);
 885         *line_p = G.pipeline.buf;
 886         return altered;
 887 }
 888
 889 /* Set command pointer to point to this label.  (Does not handle null label.) */
 890 static sed_cmd_t *branch_to(char *label)
 891 {
 892         sed_cmd_t *sed_cmd;
 893
 894         for (sed_cmd = G.sed_cmd_head; sed_cmd; sed_cmd = sed_cmd->next) {
 895                 if (sed_cmd->cmd == ':' && sed_cmd->string && !strcmp(sed_cmd->string, label)) {
 896                         return sed_cmd;
 897                 }
 898         }
 899         bb_error_msg_and_die("can't find label for jump to '%s'", label);
 900 }
 901
 902 static void append(char *s)
 903 {
 904         llist_add_to_end(&G.append_head, s);
 905 }
 906
 907 /* Output line of text. */
 908 /* Note:
 909  * The tricks with NO_EOL_CHAR and last_puts_char are there to emulate gnu sed.
 910  * Without them, we had this:
 911  * echo -n thingy >z1
 912  * echo -n again >z2
 913  * >znull
 914  * sed "s/i/z/" z1 z2 znull | hexdump -vC
 915  * output:
 916  * gnu sed 4.1.5:
 917  * 00000000  74 68 7a 6e 67 79 0a 61  67 61 7a 6e              |thzngy.agazn|
 918  * bbox:
 919  * 00000000  74 68 7a 6e 67 79 61 67  61 7a 6e                 |thzngyagazn|
 920  */
 921 enum {
 922         NO_EOL_CHAR = 1,
 923         LAST_IS_NUL = 2,
 924 };
 925 static void puts_maybe_newline(char *s, FILE *file, char *last_puts_char, char last_gets_char)
 926 {
 927         char lpc = *last_puts_char;
 928
 929         /* Need to insert a '\n' between two files because first file's
 930          * last line wasn't terminated? */
 931         if (lpc != '\n' && lpc != '\0') {
 932                 fputc('\n', file);
 933                 lpc = '\n';
 934         }
 935         fputs(s, file);
 936
 937         /* 'x' - just something which is not '\n', '\0' or NO_EOL_CHAR */
 938         if (s[0])
 939                 lpc = 'x';
 940
 941         /* had trailing '\0' and it was last char of file? */
 942         if (last_gets_char == LAST_IS_NUL) {
 943                 fputc('\0', file);
 944                 lpc = 'x'; /* */
 945         } else
 946         /* had trailing '\n' or '\0'? */
 947         if (last_gets_char != NO_EOL_CHAR) {
 948                 fputc(last_gets_char, file);
 949                 lpc = last_gets_char;
 950         }
 951
 952         if (ferror(file)) {
 953                 xfunc_error_retval = 4;  /* It's what gnu sed exits with... */
 954                 bb_error_msg_and_die(bb_msg_write_error);
 955         }
 956         *last_puts_char = lpc;
 957 }
 958
 959 static void flush_append(char *last_puts_char)
 960 {
 961         char *data;
 962
 963         /* Output appended lines. */
 964         while ((data = (char *)llist_pop(&G.append_head)) != NULL) {
 965                 /* Append command does not respect "nonterminated-ness"
 966                  * of last line. Try this:
 967                  * $ echo -n "woot" | sed -e '/woot/a woo' -
 968                  * woot
 969                  * woo
 970                  * (both lines are terminated with \n)
 971                  * Therefore we do not propagate "last_gets_char" here,
 972                  * pass '\n' instead:
 973                  */
 974                 puts_maybe_newline(data, G.nonstdout, last_puts_char, '\n');
 975                 free(data);
 976         }
 977 }
 978
 979 /* Get next line of input from G.input_file_list, flushing append buffer and
 980  * noting if we ran out of files without a newline on the last line we read.
 981  */
 982 static char *get_next_line(char *gets_char, char *last_puts_char)
 983 {
 984         char *temp = NULL;
 985         int len;
 986         char gc;
 987
 988         flush_append(last_puts_char);
 989
 990         /* will be returned if last line in the file
 991          * doesn't end with either '\n' or '\0' */
 992         gc = NO_EOL_CHAR;
 993         for (; G.current_input_file <= G.last_input_file; G.current_input_file++) {
 994                 FILE *fp = G.current_fp;
 995                 if (!fp) {
 996                         const char *path = G.input_file_list[G.current_input_file];
 997                         fp = stdin;
 998                         if (path != bb_msg_standard_input) {
 999                                 fp = fopen_or_warn(path, "r");
1000                                 if (!fp) {
1001                                         G.exitcode = EXIT_FAILURE;
1002                                         continue;
1003                                 }
1004                         }
1005                         G.current_fp = fp;
1006                 }
1007                 /* Read line up to a newline or NUL byte, inclusive,
1008                  * return malloc'ed char[]. length of the chunk read
1009                  * is stored in len. NULL if EOF/error */
1010                 temp = bb_get_chunk_from_file(fp, &len);
1011                 if (temp) {
1012                         /* len > 0 here, it's ok to do temp[len-1] */
1013                         char c = temp[len-1];
1014                         if (c == '\n' || c == '\0') {
1015                                 temp[len-1] = '\0';
1016                                 gc = c;
1017                                 if (c == '\0') {
1018                                         int ch = fgetc(fp);
1019                                         if (ch != EOF)
1020                                                 ungetc(ch, fp);
1021                                         else
1022                                                 gc = LAST_IS_NUL;
1023                                 }
1024                         }
1025                         /* else we put NO_EOL_CHAR into *gets_char */
1026                         break;
1027
1028                 /* NB: I had the idea of peeking next file(s) and returning
1029                  * NO_EOL_CHAR only if it is the *last* non-empty
1030                  * input file. But there is a case where this won't work:
1031                  * file1: "a woo\nb woo"
1032                  * file2: "c no\nd no"
1033                  * sed -ne 's/woo/bang/p' input1 input2 => "a bang\nb bang"
1034                  * (note: *no* newline after "b bang"!) */
1035                 }
1036                 /* Close this file and advance to next one */
1037                 fclose_if_not_stdin(fp);
1038                 G.current_fp = NULL;
1039         }
1040         *gets_char = gc;
1041         return temp;
1042 }
1043
1044 #define sed_puts(s, n) (puts_maybe_newline(s, G.nonstdout, &last_puts_char, n))
1045
1046 static int beg_match(sed_cmd_t *sed_cmd, const char *pattern_space)
1047 {
1048         int retval = sed_cmd->beg_match && !regexec(sed_cmd->beg_match, pattern_space, 0, NULL, 0);
1049         if (retval)
1050                 G.previous_regex_ptr = sed_cmd->beg_match;
1051         return retval;
1052 }
1053
1054 /* Process all the lines in all the files */
1055
1056 static void process_files(void)
1057 {
1058         char *pattern_space, *next_line;
1059         int linenum = 0;
1060         char last_puts_char = '\n';
1061         char last_gets_char, next_gets_char;
1062         sed_cmd_t *sed_cmd;
1063         int substituted;
1064
1065         /* Prime the pump */
1066         next_line = get_next_line(&next_gets_char, &last_puts_char);
1067
1068         /* Go through every line in each file */
1069  again:
1070         substituted = 0;
1071
1072         /* Advance to next line.  Stop if out of lines. */
1073         pattern_space = next_line;
1074         if (!pattern_space)
1075                 return;
1076         last_gets_char = next_gets_char;
1077
1078         /* Read one line in advance so we can act on the last line,
1079          * the '$' address */
1080         next_line = get_next_line(&next_gets_char, &last_puts_char);
1081         linenum++;
1082
1083         /* For every line, go through all the commands */
1084  restart:
1085         for (sed_cmd = G.sed_cmd_head; sed_cmd; sed_cmd = sed_cmd->next) {
1086                 int old_matched, matched;
1087
1088                 old_matched = sed_cmd->in_match;
1089
1090                 /* Determine if this command matches this line: */
1091
1092                 dbg("match1:%d", sed_cmd->in_match);
1093                 dbg("match2:%d", (!sed_cmd->beg_line && !sed_cmd->end_line
1094                                 && !sed_cmd->beg_match && !sed_cmd->end_match));
1095                 dbg("match3:%d", (sed_cmd->beg_line > 0
1096                         && (sed_cmd->end_line || sed_cmd->end_match
1097                             ? (sed_cmd->beg_line <= linenum)
1098                             : (sed_cmd->beg_line == linenum)
1099                             )
1100                         ));
1101                 dbg("match4:%d", (beg_match(sed_cmd, pattern_space)));
1102                 dbg("match5:%d", (sed_cmd->beg_line == -1 && next_line == NULL));
1103
1104                 /* Are we continuing a previous multi-line match? */
1105                 sed_cmd->in_match = sed_cmd->in_match
1106                         /* Or is no range necessary? */
1107                         || (!sed_cmd->beg_line && !sed_cmd->end_line
1108                                 && !sed_cmd->beg_match && !sed_cmd->end_match)
1109                         /* Or did we match the start of a numerical range? */
1110                         || (sed_cmd->beg_line > 0
1111                             && (sed_cmd->end_line || sed_cmd->end_match
1112                                   /* note: even if end is numeric and is < linenum too,
1113                                    * GNU sed matches! We match too, therefore we don't
1114                                    * check here that linenum <= end.
1115                                    * Example:
1116                                    * printf '1\n2\n3\n4\n' | sed -n '1{N;N;d};1p;2,3p;3p;4p'
1117                                    * first three input lines are deleted;
1118                                    * 4th line is matched and printed
1119                                    * by "2,3" (!) and by "4" ranges
1120                                    */
1121                                 ? (sed_cmd->beg_line <= linenum)    /* N,end */
1122                                 : (sed_cmd->beg_line == linenum)    /* N */
1123                                 )
1124                             )
1125                         /* Or does this line match our begin address regex? */
1126                         || (beg_match(sed_cmd, pattern_space))
1127                         /* Or did we match last line of input? */
1128                         || (sed_cmd->beg_line == -1 && next_line == NULL);
1129
1130                 /* Snapshot the value */
1131                 matched = sed_cmd->in_match;
1132
1133                 dbg("cmd:'%c' matched:%d beg_line:%d end_line:%d linenum:%d",
1134                         sed_cmd->cmd, matched, sed_cmd->beg_line, sed_cmd->end_line, linenum);
1135
1136                 /* Is this line the end of the current match? */
1137
1138                 if (matched) {
1139                         if (sed_cmd->end_line <= -2) {
1140                                 /* address2 is +N, i.e. N lines from beg_line */
1141                                 sed_cmd->end_line = linenum + (-sed_cmd->end_line - 2);
1142                         }
1143                         /* once matched, "n,xxx" range is dead, disabling it */
1144                         if (sed_cmd->beg_line > 0) {
1145                                 sed_cmd->beg_line = -2;
1146                         }
1147                         dbg("end1:%d", sed_cmd->end_line ? sed_cmd->end_line == -1
1148                                                 ? !next_line : (sed_cmd->end_line <= linenum)
1149                                         : !sed_cmd->end_match);
1150                         dbg("end2:%d", sed_cmd->end_match && old_matched
1151                                         && !regexec(sed_cmd->end_match,pattern_space, 0, NULL, 0));
1152                         sed_cmd->in_match = !(
1153                                 /* has the ending line come, or is this a single address command? */
1154                                 (sed_cmd->end_line
1155                                         ? sed_cmd->end_line == -1
1156                                                 ? !next_line
1157                                                 : (sed_cmd->end_line <= linenum)
1158                                         : !sed_cmd->end_match
1159                                 )
1160                                 /* or does this line matches our last address regex */
1161                                 || (sed_cmd->end_match && old_matched
1162                                      && (regexec(sed_cmd->end_match,
1163                                                 pattern_space, 0, NULL, 0) == 0)
1164                                 )
1165                         );
1166                 }
1167
1168                 /* Skip blocks of commands we didn't match */
1169                 if (sed_cmd->cmd == '{') {
1170                         if (sed_cmd->invert ? matched : !matched) {
1171                                 unsigned nest_cnt = 0;
1172                                 while (1) {
1173                                         if (sed_cmd->cmd == '{')
1174                                                 nest_cnt++;
1175                                         if (sed_cmd->cmd == '}') {
1176                                                 nest_cnt--;
1177                                                 if (nest_cnt == 0)
1178                                                         break;
1179                                         }
1180                                         sed_cmd = sed_cmd->next;
1181                                         if (!sed_cmd)
1182                                                 bb_error_msg_and_die("unterminated {");
1183                                 }
1184                         }
1185                         continue;
1186                 }
1187
1188                 /* Okay, so did this line match? */
1189                 if (sed_cmd->invert ? matched : !matched)
1190                         continue; /* no */
1191
1192                 /* Update last used regex in case a blank substitute BRE is found */
1193                 if (sed_cmd->beg_match) {
1194                         G.previous_regex_ptr = sed_cmd->beg_match;
1195                 }
1196
1197                 /* actual sedding */
1198                 dbg("pattern_space:'%s' next_line:'%s' cmd:%c",
1199                                 pattern_space, next_line, sed_cmd->cmd);
1200                 switch (sed_cmd->cmd) {
1201
1202                 /* Print line number */
1203                 case '=':
1204                         fprintf(G.nonstdout, "%d\n", linenum);
1205                         break;
1206
1207                 /* Write the current pattern space up to the first newline */
1208                 case 'P':
1209                 {
1210                         char *tmp = strchr(pattern_space, '\n');
1211                         if (tmp) {
1212                                 *tmp = '\0';
1213                                 /* TODO: explain why '\n' below */
1214                                 sed_puts(pattern_space, '\n');
1215                                 *tmp = '\n';
1216                                 break;
1217                         }
1218                         /* Fall Through */
1219                 }
1220
1221                 /* Write the current pattern space to output */
1222                 case 'p':
1223                         /* NB: we print this _before_ the last line
1224                          * (of current file) is printed. Even if
1225                          * that line is nonterminated, we print
1226                          * '\n' here (gnu sed does the same) */
1227                         sed_puts(pattern_space, '\n');
1228                         break;
1229                 /* Delete up through first newline */
1230                 case 'D':
1231                 {
1232                         char *tmp = strchr(pattern_space, '\n');
1233                         if (tmp) {
1234                                 overlapping_strcpy(pattern_space, tmp + 1);
1235                                 goto restart;
1236                         }
1237                 }
1238                 /* discard this line. */
1239                 case 'd':
1240                         goto discard_line;
1241
1242                 /* Substitute with regex */
1243                 case 's':
1244                         if (!do_subst_command(sed_cmd, &pattern_space))
1245                                 break;
1246                         dbg("do_subst_command succeeded:'%s'", pattern_space);
1247                         substituted |= 1;
1248
1249                         /* handle p option */
1250                         if (sed_cmd->sub_p)
1251                                 sed_puts(pattern_space, last_gets_char);
1252                         /* handle w option */
1253                         if (sed_cmd->sw_file)
1254                                 puts_maybe_newline(
1255                                         pattern_space, sed_cmd->sw_file,
1256                                         &sed_cmd->sw_last_char, last_gets_char);
1257                         break;
1258
1259                 /* Append line to linked list to be printed later */
1260                 case 'a':
1261                         append(xstrdup(sed_cmd->string));
1262                         break;
1263
1264                 /* Insert text before this line */
1265                 case 'i':
1266                         sed_puts(sed_cmd->string, '\n');
1267                         break;
1268
1269                 /* Cut and paste text (replace) */
1270                 case 'c':
1271                         /* Only triggers on last line of a matching range. */
1272                         if (!sed_cmd->in_match)
1273                                 sed_puts(sed_cmd->string, '\n');
1274                         goto discard_line;
1275
1276                 /* Read file, append contents to output */
1277                 case 'r':
1278                 {
1279                         FILE *rfile;
1280                         rfile = fopen_for_read(sed_cmd->string);
1281                         if (rfile) {
1282                                 char *line;
1283                                 while ((line = xmalloc_fgetline(rfile))
1284                                                 != NULL)
1285                                         append(line);
1286                                 fclose(rfile);
1287                         }
1288
1289                         break;
1290                 }
1291
1292                 /* Write pattern space to file. */
1293                 case 'w':
1294                         puts_maybe_newline(
1295                                 pattern_space, sed_cmd->sw_file,
1296                                 &sed_cmd->sw_last_char, last_gets_char);
1297                         break;
1298
1299                 /* Read next line from input */
1300                 case 'n':
1301                         if (!G.be_quiet)
1302                                 sed_puts(pattern_space, last_gets_char);
1303                         if (next_line == NULL) {
1304                                 /* If no next line, jump to end of script and exit. */
1305                                 goto discard_line;
1306                         }
1307                         free(pattern_space);
1308                         pattern_space = next_line;
1309                         last_gets_char = next_gets_char;
1310                         next_line = get_next_line(&next_gets_char, &last_puts_char);
1311                         substituted = 0;
1312                         linenum++;
1313                         break;
1314
1315                 /* Quit.  End of script, end of input. */
1316                 case 'q':
1317                         /* Exit the outer while loop */
1318                         free(next_line);
1319                         next_line = NULL;
1320                         goto discard_commands;
1321
1322                 /* Append the next line to the current line */
1323                 case 'N':
1324                 {
1325                         int len;
1326                         /* If no next line, jump to end of script and exit. */
1327                         /* http://www.gnu.org/software/sed/manual/sed.html:
1328                          * "Most versions of sed exit without printing anything
1329                          * when the N command is issued on the last line of
1330                          * a file. GNU sed prints pattern space before exiting
1331                          * unless of course the -n command switch has been
1332                          * specified. This choice is by design."
1333                          */
1334                         if (next_line == NULL) {
1335                                 //goto discard_line;
1336                                 goto discard_commands; /* GNU behavior */
1337                         }
1338                         /* Append next_line, read new next_line. */
1339                         len = strlen(pattern_space);
1340                         pattern_space = xrealloc(pattern_space, len + strlen(next_line) + 2);
1341                         pattern_space[len] = '\n';
1342                         strcpy(pattern_space + len+1, next_line);
1343                         last_gets_char = next_gets_char;
1344                         next_line = get_next_line(&next_gets_char, &last_puts_char);
1345                         linenum++;
1346                         break;
1347                 }
1348
1349                 /* Test/branch if substitution occurred */
1350                 case 't':
1351                         if (!substituted) break;
1352                         substituted = 0;
1353                         /* Fall through */
1354                 /* Test/branch if substitution didn't occur */
1355                 case 'T':
1356                         if (substituted) break;
1357                         /* Fall through */
1358                 /* Branch to label */
1359                 case 'b':
1360                         if (!sed_cmd->string) goto discard_commands;
1361                         else sed_cmd = branch_to(sed_cmd->string);
1362                         break;
1363                 /* Transliterate characters */
1364                 case 'y':
1365                 {
1366                         int i, j;
1367                         for (i = 0; pattern_space[i]; i++) {
1368                                 for (j = 0; sed_cmd->string[j]; j += 2) {
1369                                         if (pattern_space[i] == sed_cmd->string[j]) {
1370                                                 pattern_space[i] = sed_cmd->string[j + 1];
1371                                                 break;
1372                                         }
1373                                 }
1374                         }
1375
1376                         break;
1377                 }
1378                 case 'g':       /* Replace pattern space with hold space */
1379                         free(pattern_space);
1380                         pattern_space = xstrdup(G.hold_space ? G.hold_space : "");
1381                         break;
1382                 case 'G':       /* Append newline and hold space to pattern space */
1383                 {
1384                         int pattern_space_size = 2;
1385                         int hold_space_size = 0;
1386
1387                         if (pattern_space)
1388                                 pattern_space_size += strlen(pattern_space);
1389                         if (G.hold_space)
1390                                 hold_space_size = strlen(G.hold_space);
1391                         pattern_space = xrealloc(pattern_space,
1392                                         pattern_space_size + hold_space_size);
1393                         if (pattern_space_size == 2)
1394                                 pattern_space[0] = 0;
1395                         strcat(pattern_space, "\n");
1396                         if (G.hold_space)
1397                                 strcat(pattern_space, G.hold_space);
1398                         last_gets_char = '\n';
1399
1400                         break;
1401                 }
1402                 case 'h':       /* Replace hold space with pattern space */
1403                         free(G.hold_space);
1404                         G.hold_space = xstrdup(pattern_space);
1405                         break;
1406                 case 'H':       /* Append newline and pattern space to hold space */
1407                 {
1408                         int hold_space_size = 2;
1409                         int pattern_space_size = 0;
1410
1411                         if (G.hold_space)
1412                                 hold_space_size += strlen(G.hold_space);
1413                         if (pattern_space)
1414                                 pattern_space_size = strlen(pattern_space);
1415                         G.hold_space = xrealloc(G.hold_space,
1416                                         hold_space_size + pattern_space_size);
1417
1418                         if (hold_space_size == 2)
1419                                 *G.hold_space = 0;
1420                         strcat(G.hold_space, "\n");
1421                         if (pattern_space)
1422                                 strcat(G.hold_space, pattern_space);
1423
1424                         break;
1425                 }
1426                 case 'x': /* Exchange hold and pattern space */
1427                 {
1428                         char *tmp = pattern_space;
1429                         pattern_space = G.hold_space ? G.hold_space : xzalloc(1);
1430                         last_gets_char = '\n';
1431                         G.hold_space = tmp;
1432                         break;
1433                 }
1434                 } /* switch */
1435         } /* for each cmd */
1436
1437         /*
1438          * Exit point from sedding...
1439          */
1440  discard_commands:
1441         /* we will print the line unless we were told to be quiet ('-n')
1442            or if the line was suppressed (ala 'd'elete) */
1443         if (!G.be_quiet)
1444                 sed_puts(pattern_space, last_gets_char);
1445
1446         /* Delete and such jump here. */
1447  discard_line:
1448         flush_append(&last_puts_char /*,last_gets_char*/);
1449         free(pattern_space);
1450
1451         goto again;
1452 }
1453
1454 /* It is possible to have a command line argument with embedded
1455  * newlines.  This counts as multiple command lines.
1456  * However, newline can be escaped: 's/e/z\<newline>z/'
1457  * add_cmd() handles this.
1458  */
1459
1460 static void add_cmd_block(char *cmdstr)
1461 {
1462         char *sv, *eol;
1463
1464         cmdstr = sv = xstrdup(cmdstr);
1465         do {
1466                 eol = strchr(cmdstr, '\n');
1467                 if (eol)
1468                         *eol = '\0';
1469                 add_cmd(cmdstr);
1470                 cmdstr = eol + 1;
1471         } while (eol);
1472         free(sv);
1473 }
1474
1475 int sed_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1476 int sed_main(int argc UNUSED_PARAM, char **argv)
1477 {
1478         unsigned opt;
1479         llist_t *opt_e, *opt_f;
1480         char *opt_i;
1481
1482 #if ENABLE_LONG_OPTS
1483         static const char sed_longopts[] ALIGN1 =
1484                 /* name             has_arg             short */
1485                 "in-place\0"        Optional_argument   "i"
1486                 "regexp-extended\0" No_argument         "r"
1487                 "quiet\0"           No_argument         "n"
1488                 "silent\0"          No_argument         "n"
1489                 "expression\0"      Required_argument   "e"
1490                 "file\0"            Required_argument   "f";
1491 #endif
1492
1493         INIT_G();
1494
1495         /* destroy command strings on exit */
1496         if (ENABLE_FEATURE_CLEAN_UP) atexit(sed_free_and_close_stuff);
1497
1498         /* Lie to autoconf when it starts asking stupid questions. */
1499         if (argv[1] && strcmp(argv[1], "--version") == 0) {
1500                 puts("This is not GNU sed version 4.0");
1501                 return 0;
1502         }
1503
1504         /* do normal option parsing */
1505         opt_e = opt_f = NULL;
1506         opt_i = NULL;
1507         opt_complementary = "nn"; /* count -n */
1508
1509         IF_LONG_OPTS(applet_long_options = sed_longopts);
1510
1511         /* -i must be first, to match OPT_in_place definition */
1512         /* -E is a synonym of -r:
1513          * GNU sed 4.2.1 mentions it in neither --help
1514          * nor manpage, but does recognize it.
1515          */
1516         opt = getopt32(argv, "i::rEne:*f:*", &opt_i, &opt_e, &opt_f,
1517                             &G.be_quiet); /* counter for -n */
1518         //argc -= optind;
1519         argv += optind;
1520         if (opt & OPT_in_place) { // -i
1521                 atexit(cleanup_outname);
1522         }
1523         if (opt & (2|4))
1524                 G.regex_type |= REG_EXTENDED; // -r or -E
1525         //if (opt & 8)
1526         //      G.be_quiet++; // -n (implemented with a counter instead)
1527         while (opt_e) { // -e
1528                 add_cmd_block(llist_pop(&opt_e));
1529         }
1530         while (opt_f) { // -f
1531                 char *line;
1532                 FILE *cmdfile;
1533                 cmdfile = xfopen_stdin(llist_pop(&opt_f));
1534                 while ((line = xmalloc_fgetline(cmdfile)) != NULL) {
1535                         add_cmd(line);
1536                         free(line);
1537                 }
1538                 fclose_if_not_stdin(cmdfile);
1539         }
1540         /* if we didn't get a pattern from -e or -f, use argv[0] */
1541         if (!(opt & 0x30)) {
1542                 if (!*argv)
1543                         bb_show_usage();
1544                 add_cmd_block(*argv++);
1545         }
1546         /* Flush any unfinished commands. */
1547         add_cmd("");
1548
1549         /* By default, we write to stdout */
1550         G.nonstdout = stdout;
1551
1552         /* argv[0..(argc-1)] should be names of file to process. If no
1553          * files were specified or '-' was specified, take input from stdin.
1554          * Otherwise, we process all the files specified. */
1555         G.input_file_list = argv;
1556         if (!argv[0]) {
1557                 if (opt & OPT_in_place)
1558                         bb_error_msg_and_die(bb_msg_requires_arg, "-i");
1559                 argv[0] = (char*)bb_msg_standard_input;
1560                 /* G.last_input_file = 0; - already is */
1561         } else {
1562                 goto start;
1563
1564                 for (; *argv; argv++) {
1565                         struct stat statbuf;
1566                         int nonstdoutfd;
1567                         sed_cmd_t *sed_cmd;
1568
1569                         G.last_input_file++;
1570  start:
1571                         if (!(opt & OPT_in_place)) {
1572                                 if (LONE_DASH(*argv)) {
1573                                         *argv = (char*)bb_msg_standard_input;
1574                                         process_files();
1575                                 }
1576                                 continue;
1577                         }
1578
1579                         /* -i: process each FILE separately: */
1580
1581                         if (stat(*argv, &statbuf) != 0) {
1582                                 bb_simple_perror_msg(*argv);
1583                                 G.exitcode = EXIT_FAILURE;
1584                                 G.current_input_file++;
1585                                 continue;
1586                         }
1587                         G.outname = xasprintf("%sXXXXXX", *argv);
1588                         nonstdoutfd = xmkstemp(G.outname);
1589                         G.nonstdout = xfdopen_for_write(nonstdoutfd);
1590                         /* Set permissions/owner of output file */
1591                         /* chmod'ing AFTER chown would preserve suid/sgid bits,
1592                          * but GNU sed 4.2.1 does not preserve them either */
1593                         fchmod(nonstdoutfd, statbuf.st_mode);
1594                         fchown(nonstdoutfd, statbuf.st_uid, statbuf.st_gid);
1595
1596                         process_files();
1597                         fclose(G.nonstdout);
1598                         G.nonstdout = stdout;
1599
1600                         if (opt_i) {
1601                                 char *backupname = xasprintf("%s%s", *argv, opt_i);
1602                                 xrename(*argv, backupname);
1603                                 free(backupname);
1604                         }
1605                         /* else unlink(*argv); - rename below does this */
1606                         xrename(G.outname, *argv); //TODO: rollback backup on error?
1607                         free(G.outname);
1608                         G.outname = NULL;
1609
1610                         /* Fix disabled range matches and mangled ",+N" ranges */
1611                         for (sed_cmd = G.sed_cmd_head; sed_cmd; sed_cmd = sed_cmd->next) {
1612                                 sed_cmd->beg_line = sed_cmd->beg_line_orig;
1613                                 sed_cmd->end_line = sed_cmd->end_line_orig;
1614                         }
1615                 }
1616                 /* Here, to handle "sed 'cmds' nonexistent_file" case we did:
1617                  * if (G.current_input_file[G.current_input_file] == NULL)
1618                  *      return G.exitcode;
1619                  * but it's not needed since process_files() works correctly
1620                  * in this case too. */
1621         }
1622
1623         process_files();
1624
1625         return G.exitcode;
1626 }