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  * add_input_file() adds a FILE* to the list of input files.  We need to
  27  * know all input sources ahead of time to find the last line for the $ match.
  28  *
  29  * process_files() does actual sedding, reading data lines from each input FILE *
  30  * (which could be stdin) and applying the sed command list (sed_cmd_head) to
  31  * each of the resulting lines.
  32  *
  33  * sed_main() is where external code calls into this, with a command line.
  34  */
  35
  36 /* Supported features and commands in this version of sed:
  37  *
  38  * - comments ('#')
  39  * - address matching: num|/matchstr/[,num|/matchstr/|$]command
  40  * - commands: (p)rint, (d)elete, (s)ubstitue (with g & I flags)
  41  * - edit commands: (a)ppend, (i)nsert, (c)hange
  42  * - file commands: (r)ead
  43  * - backreferences in substitution expressions (\0, \1, \2...\9)
  44  * - grouped commands: {cmd1;cmd2}
  45  * - transliteration (y/source-chars/dest-chars/)
  46  * - pattern space hold space storing / swapping (g, h, x)
  47  * - labels / branching (: label, b, t, T)
  48  *
  49  * (Note: Specifying an address (range) to match is *optional*; commands
  50  * default to the whole pattern space if no specific address match was
  51  * requested.)
  52  *
  53  * Todo:
  54  * - Create a wrapper around regex to make libc's regex conform with sed
  55  *
  56  * Reference http://www.opengroup.org/onlinepubs/007904975/utilities/sed.html
  57  */
  58
  59 //usage:#define sed_trivial_usage
  60 //usage:       "[-efinr] SED_CMD [FILE]..."
  61 //usage:#define sed_full_usage "\n\n"
  62 //usage:       "        -e CMD  Add CMD to sed commands to be executed"
  63 //usage:     "\n        -f FILE Add FILE contents to sed commands to be executed"
  64 //usage:     "\n        -i      Edit files in-place (else sends result to stdout)"
  65 //usage:     "\n        -n      Suppress automatic printing of pattern space"
  66 //usage:     "\n        -r      Use extended regex syntax"
  67 //usage:     "\n"
  68 //usage:     "\nIf no -e or -f, the first non-option argument is the sed command string."
  69 //usage:     "\nRemaining arguments are input files (stdin if none)."
  70 //usage:
  71 //usage:#define sed_example_usage
  72 //usage:       "$ echo \"foo\" | sed -e 's/f[a-zA-Z]o/bar/g'\n"
  73 //usage:       "bar\n"
  74
  75 #include "libbb.h"
  76 #include "xregex.h"
  77
  78 #if 0
  79 # define dbg(...) bb_error_msg(__VA_ARGS__)
  80 #else
  81 # define dbg(...) ((void)0)
  82 #endif
  83
  84
  85 enum {
  86         OPT_in_place = 1 << 0,
  87 };
  88
  89 /* Each sed command turns into one of these structures. */
  90 typedef struct sed_cmd_s {
  91         /* Ordered by alignment requirements: currently 36 bytes on x86 */
  92         struct sed_cmd_s *next; /* Next command (linked list, NULL terminated) */
  93
  94         /* address storage */
  95         regex_t *beg_match;     /* sed -e '/match/cmd' */
  96         regex_t *end_match;     /* sed -e '/match/,/end_match/cmd' */
  97         regex_t *sub_match;     /* For 's/sub_match/string/' */
  98         int beg_line;           /* 'sed 1p'   0 == apply commands to all lines */
  99         int beg_line_orig;      /* copy of the above, needed for -i */
 100         int end_line;           /* 'sed 1,3p' 0 == one line only. -1 = last line ($) */
 101
 102         FILE *sw_file;          /* File (sw) command writes to, -1 for none. */
 103         char *string;           /* Data string for (saicytb) commands. */
 104
 105         unsigned which_match;   /* (s) Which match to replace (0 for all) */
 106
 107         /* Bitfields (gcc won't group them if we don't) */
 108         unsigned invert:1;      /* the '!' after the address */
 109         unsigned in_match:1;    /* Next line also included in match? */
 110         unsigned sub_p:1;       /* (s) print option */
 111
 112         char sw_last_char;      /* Last line written by (sw) had no '\n' */
 113
 114         /* GENERAL FIELDS */
 115         char cmd;               /* The command char: abcdDgGhHilnNpPqrstwxy:={} */
 116 } sed_cmd_t;
 117
 118 static const char semicolon_whitespace[] ALIGN1 = "; \n\r\t\v";
 119
 120 struct globals {
 121         /* options */
 122         int be_quiet, regex_type;
 123         FILE *nonstdout;
 124         char *outname, *hold_space;
 125
 126         /* List of input files */
 127         int input_file_count, current_input_file;
 128         FILE **input_file_list;
 129
 130         regmatch_t regmatch[10];
 131         regex_t *previous_regex_ptr;
 132
 133         /* linked list of sed commands */
 134         sed_cmd_t *sed_cmd_head, **sed_cmd_tail;
 135
 136         /* Linked list of append lines */
 137         llist_t *append_head;
 138
 139         char *add_cmd_line;
 140
 141         struct pipeline {
 142                 char *buf;  /* Space to hold string */
 143                 int idx;    /* Space used */
 144                 int len;    /* Space allocated */
 145         } pipeline;
 146 } FIX_ALIASING;
 147 #define G (*(struct globals*)&bb_common_bufsiz1)
 148 struct BUG_G_too_big {
 149         char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
 150 };
 151 #define INIT_G() do { \
 152         G.sed_cmd_tail = &G.sed_cmd_head; \
 153 } while (0)
 154
 155
 156 #if ENABLE_FEATURE_CLEAN_UP
 157 static void sed_free_and_close_stuff(void)
 158 {
 159         sed_cmd_t *sed_cmd = G.sed_cmd_head;
 160
 161         llist_free(G.append_head, free);
 162
 163         while (sed_cmd) {
 164                 sed_cmd_t *sed_cmd_next = sed_cmd->next;
 165
 166                 if (sed_cmd->sw_file)
 167                         xprint_and_close_file(sed_cmd->sw_file);
 168
 169                 if (sed_cmd->beg_match) {
 170                         regfree(sed_cmd->beg_match);
 171                         free(sed_cmd->beg_match);
 172                 }
 173                 if (sed_cmd->end_match) {
 174                         regfree(sed_cmd->end_match);
 175                         free(sed_cmd->end_match);
 176                 }
 177                 if (sed_cmd->sub_match) {
 178                         regfree(sed_cmd->sub_match);
 179                         free(sed_cmd->sub_match);
 180                 }
 181                 free(sed_cmd->string);
 182                 free(sed_cmd);
 183                 sed_cmd = sed_cmd_next;
 184         }
 185
 186         free(G.hold_space);
 187
 188         while (G.current_input_file < G.input_file_count)
 189                 fclose(G.input_file_list[G.current_input_file++]);
 190 }
 191 #else
 192 void sed_free_and_close_stuff(void);
 193 #endif
 194
 195 /* If something bad happens during -i operation, delete temp file */
 196
 197 static void cleanup_outname(void)
 198 {
 199         if (G.outname) unlink(G.outname);
 200 }
 201
 202 /* strcpy, replacing "\from" with 'to'. If to is NUL, replacing "\any" with 'any' */
 203
 204 static void parse_escapes(char *dest, const char *string, int len, char from, char to)
 205 {
 206         int i = 0;
 207
 208         while (i < len) {
 209                 if (string[i] == '\\') {
 210                         if (!to || string[i+1] == from) {
 211                                 *dest++ = to ? to : string[i+1];
 212                                 i += 2;
 213                                 continue;
 214                         }
 215                         *dest++ = string[i++];
 216                 }
 217                 /* TODO: is it safe wrt a string with trailing '\\' ? */
 218                 *dest++ = string[i++];
 219         }
 220         *dest = '\0';
 221 }
 222
 223 static char *copy_parsing_escapes(const char *string, int len)
 224 {
 225         const char *s;
 226         char *dest = xmalloc(len + 1);
 227
 228         /* sed recognizes \n */
 229         /* GNU sed also recognizes \t and \r */
 230         for (s = "\nn\tt\rr"; *s; s += 2) {
 231                 parse_escapes(dest, string, len, s[1], s[0]);
 232                 string = dest;
 233                 len = strlen(dest);
 234         }
 235         return dest;
 236 }
 237
 238
 239 /*
 240  * index_of_next_unescaped_regexp_delim - walks left to right through a string
 241  * beginning at a specified index and returns the index of the next regular
 242  * expression delimiter (typically a forward slash ('/')) not preceded by
 243  * a backslash ('\').  A negative delimiter disables square bracket checking.
 244  */
 245 static int index_of_next_unescaped_regexp_delim(int delimiter, const char *str)
 246 {
 247         int bracket = -1;
 248         int escaped = 0;
 249         int idx = 0;
 250         char ch;
 251
 252         if (delimiter < 0) {
 253                 bracket--;
 254                 delimiter = -delimiter;
 255         }
 256
 257         for (; (ch = str[idx]) != '\0'; idx++) {
 258                 if (bracket >= 0) {
 259                         if (ch == ']'
 260                          && !(bracket == idx - 1 || (bracket == idx - 2 && str[idx - 1] == '^'))
 261                         ) {
 262                                 bracket = -1;
 263                         }
 264                 } else if (escaped)
 265                         escaped = 0;
 266                 else if (ch == '\\')
 267                         escaped = 1;
 268                 else if (bracket == -1 && ch == '[')
 269                         bracket = idx;
 270                 else if (ch == delimiter)
 271                         return idx;
 272         }
 273
 274         /* if we make it to here, we've hit the end of the string */
 275         bb_error_msg_and_die("unmatched '%c'", delimiter);
 276 }
 277
 278 /*
 279  *  Returns the index of the third delimiter
 280  */
 281 static int parse_regex_delim(const char *cmdstr, char **match, char **replace)
 282 {
 283         const char *cmdstr_ptr = cmdstr;
 284         char delimiter;
 285         int idx = 0;
 286
 287         /* verify that the 's' or 'y' is followed by something.  That something
 288          * (typically a 'slash') is now our regexp delimiter... */
 289         if (*cmdstr == '\0')
 290                 bb_error_msg_and_die("bad format in substitution expression");
 291         delimiter = *cmdstr_ptr++;
 292
 293         /* save the match string */
 294         idx = index_of_next_unescaped_regexp_delim(delimiter, cmdstr_ptr);
 295         *match = copy_parsing_escapes(cmdstr_ptr, idx);
 296
 297         /* save the replacement string */
 298         cmdstr_ptr += idx + 1;
 299         idx = index_of_next_unescaped_regexp_delim(-delimiter, cmdstr_ptr);
 300         *replace = copy_parsing_escapes(cmdstr_ptr, idx);
 301
 302         return ((cmdstr_ptr - cmdstr) + idx);
 303 }
 304
 305 /*
 306  * returns the index in the string just past where the address ends.
 307  */
 308 static int get_address(const char *my_str, int *linenum, regex_t ** regex)
 309 {
 310         const char *pos = my_str;
 311
 312         if (isdigit(*my_str)) {
 313                 *linenum = strtol(my_str, (char**)&pos, 10);
 314                 /* endstr shouldnt ever equal NULL */
 315         } else if (*my_str == '$') {
 316                 *linenum = -1;
 317                 pos++;
 318         } else if (*my_str == '/' || *my_str == '\\') {
 319                 int next;
 320                 char delimiter;
 321                 char *temp;
 322
 323                 delimiter = '/';
 324                 if (*my_str == '\\') delimiter = *++pos;
 325                 next = index_of_next_unescaped_regexp_delim(delimiter, ++pos);
 326                 temp = copy_parsing_escapes(pos, next);
 327                 *regex = xmalloc(sizeof(regex_t));
 328                 xregcomp(*regex, temp, G.regex_type|REG_NEWLINE);
 329                 free(temp);
 330                 /* Move position to next character after last delimiter */
 331                 pos += (next+1);
 332         }
 333         return pos - my_str;
 334 }
 335
 336 /* Grab a filename.  Whitespace at start is skipped, then goes to EOL. */
 337 static int parse_file_cmd(/*sed_cmd_t *sed_cmd,*/ const char *filecmdstr, char **retval)
 338 {
 339         int start = 0, idx, hack = 0;
 340
 341         /* Skip whitespace, then grab filename to end of line */
 342         while (isspace(filecmdstr[start]))
 343                 start++;
 344         idx = start;
 345         while (filecmdstr[idx] && filecmdstr[idx] != '\n')
 346                 idx++;
 347
 348         /* If lines glued together, put backslash back. */
 349         if (filecmdstr[idx] == '\n')
 350                 hack = 1;
 351         if (idx == start)
 352                 bb_error_msg_and_die("empty filename");
 353         *retval = xstrndup(filecmdstr+start, idx-start+hack+1);
 354         if (hack)
 355                 (*retval)[idx] = '\\';
 356
 357         return idx;
 358 }
 359
 360 static int parse_subst_cmd(sed_cmd_t *sed_cmd, const char *substr)
 361 {
 362         int cflags = G.regex_type;
 363         char *match;
 364         int idx;
 365
 366         /*
 367          * A substitution command should look something like this:
 368          *    s/match/replace/ #gIpw
 369          *    ||     |        |||
 370          *    mandatory       optional
 371          */
 372         idx = parse_regex_delim(substr, &match, &sed_cmd->string);
 373
 374         /* determine the number of back references in the match string */
 375         /* Note: we compute this here rather than in the do_subst_command()
 376          * function to save processor time, at the expense of a little more memory
 377          * (4 bits) per sed_cmd */
 378
 379         /* process the flags */
 380
 381         sed_cmd->which_match = 1;
 382         while (substr[++idx]) {
 383                 /* Parse match number */
 384                 if (isdigit(substr[idx])) {
 385                         if (match[0] != '^') {
 386                                 /* Match 0 treated as all, multiple matches we take the last one. */
 387                                 const char *pos = substr + idx;
 388 /* FIXME: error check? */
 389                                 sed_cmd->which_match = (unsigned)strtol(substr+idx, (char**) &pos, 10);
 390                                 idx = pos - substr;
 391                         }
 392                         continue;
 393                 }
 394                 /* Skip spaces */
 395                 if (isspace(substr[idx]))
 396                         continue;
 397
 398                 switch (substr[idx]) {
 399                 /* Replace all occurrences */
 400                 case 'g':
 401                         if (match[0] != '^')
 402                                 sed_cmd->which_match = 0;
 403                         break;
 404                 /* Print pattern space */
 405                 case 'p':
 406                         sed_cmd->sub_p = 1;
 407                         break;
 408                 /* Write to file */
 409                 case 'w':
 410                 {
 411                         char *temp;
 412                         idx += parse_file_cmd(/*sed_cmd,*/ substr+idx, &temp);
 413                         break;
 414                 }
 415                 /* Ignore case (gnu exension) */
 416                 case 'I':
 417                         cflags |= REG_ICASE;
 418                         break;
 419                 /* Comment */
 420                 case '#':
 421                         // while (substr[++idx]) continue;
 422                         idx += strlen(substr + idx); // same
 423                         /* Fall through */
 424                 /* End of command */
 425                 case ';':
 426                 case '}':
 427                         goto out;
 428                 default:
 429                         bb_error_msg_and_die("bad option in substitution expression");
 430                 }
 431         }
 432  out:
 433         /* compile the match string into a regex */
 434         if (*match != '\0') {
 435                 /* If match is empty, we use last regex used at runtime */
 436                 sed_cmd->sub_match = xmalloc(sizeof(regex_t));
 437                 xregcomp(sed_cmd->sub_match, match, cflags);
 438         }
 439         free(match);
 440
 441         return idx;
 442 }
 443
 444 /*
 445  *  Process the commands arguments
 446  */
 447 static const char *parse_cmd_args(sed_cmd_t *sed_cmd, const char *cmdstr)
 448 {
 449         static const char cmd_letters[] = "saicrw:btTydDgGhHlnNpPqx={}";
 450         enum {
 451                 IDX_s = 0,
 452                 IDX_a,
 453                 IDX_i,
 454                 IDX_c,
 455                 IDX_r,
 456                 IDX_w,
 457                 IDX_colon,
 458                 IDX_b,
 459                 IDX_t,
 460                 IDX_T,
 461                 IDX_y,
 462                 IDX_d,
 463                 IDX_D,
 464                 IDX_g,
 465                 IDX_G,
 466                 IDX_h,
 467                 IDX_H,
 468                 IDX_l,
 469                 IDX_n,
 470                 IDX_N,
 471                 IDX_p,
 472                 IDX_P,
 473                 IDX_q,
 474                 IDX_x,
 475                 IDX_equal,
 476                 IDX_lbrace,
 477                 IDX_rbrace,
 478                 IDX_nul
 479         };
 480         struct chk { char chk[sizeof(cmd_letters)-1 == IDX_nul ? 1 : -1]; };
 481
 482         unsigned idx = strchrnul(cmd_letters, sed_cmd->cmd) - cmd_letters;
 483
 484         /* handle (s)ubstitution command */
 485         if (idx == IDX_s) {
 486                 cmdstr += parse_subst_cmd(sed_cmd, cmdstr);
 487         }
 488         /* handle edit cmds: (a)ppend, (i)nsert, and (c)hange */
 489         else if (idx <= IDX_c) { /* a,i,c */
 490                 if ((sed_cmd->end_line || sed_cmd->end_match) && sed_cmd->cmd != 'c')
 491                         bb_error_msg_and_die("only a beginning address can be specified for edit commands");
 492                 for (;;) {
 493                         if (*cmdstr == '\n' || *cmdstr == '\\') {
 494                                 cmdstr++;
 495                                 break;
 496                         }
 497                         if (!isspace(*cmdstr))
 498                                 break;
 499                         cmdstr++;
 500                 }
 501                 sed_cmd->string = xstrdup(cmdstr);
 502                 /* "\anychar" -> "anychar" */
 503                 parse_escapes(sed_cmd->string, sed_cmd->string, strlen(cmdstr), '\0', '\0');
 504                 cmdstr += strlen(cmdstr);
 505         }
 506         /* handle file cmds: (r)ead */
 507         else if (idx <= IDX_w) { /* r,w */
 508                 if (sed_cmd->end_line || sed_cmd->end_match)
 509                         bb_error_msg_and_die("command only uses one address");
 510                 cmdstr += parse_file_cmd(/*sed_cmd,*/ cmdstr, &sed_cmd->string);
 511                 if (sed_cmd->cmd == 'w') {
 512                         sed_cmd->sw_file = xfopen_for_write(sed_cmd->string);
 513                         sed_cmd->sw_last_char = '\n';
 514                 }
 515         }
 516         /* handle branch commands */
 517         else if (idx <= IDX_T) { /* :,b,t,T */
 518                 int length;
 519
 520                 cmdstr = skip_whitespace(cmdstr);
 521                 length = strcspn(cmdstr, semicolon_whitespace);
 522                 if (length) {
 523                         sed_cmd->string = xstrndup(cmdstr, length);
 524                         cmdstr += length;
 525                 }
 526         }
 527         /* translation command */
 528         else if (idx == IDX_y) {
 529                 char *match, *replace;
 530                 int i = cmdstr[0];
 531
 532                 cmdstr += parse_regex_delim(cmdstr, &match, &replace)+1;
 533                 /* \n already parsed, but \delimiter needs unescaping. */
 534                 parse_escapes(match, match, strlen(match), i, i);
 535                 parse_escapes(replace, replace, strlen(replace), i, i);
 536
 537                 sed_cmd->string = xzalloc((strlen(match) + 1) * 2);
 538                 for (i = 0; match[i] && replace[i]; i++) {
 539                         sed_cmd->string[i*2] = match[i];
 540                         sed_cmd->string[i*2+1] = replace[i];
 541                 }
 542                 free(match);
 543                 free(replace);
 544         }
 545         /* if it wasnt a single-letter command that takes no arguments
 546          * then it must be an invalid command.
 547          */
 548         else if (idx >= IDX_nul) { /* not d,D,g,G,h,H,l,n,N,p,P,q,x,=,{,} */
 549                 bb_error_msg_and_die("unsupported command %c", sed_cmd->cmd);
 550         }
 551
 552         /* give back whatever's left over */
 553         return cmdstr;
 554 }
 555
 556
 557 /* Parse address+command sets, skipping comment lines. */
 558
 559 static void add_cmd(const char *cmdstr)
 560 {
 561         sed_cmd_t *sed_cmd;
 562         unsigned len, n;
 563
 564         /* Append this line to any unfinished line from last time. */
 565         if (G.add_cmd_line) {
 566                 char *tp = xasprintf("%s\n%s", G.add_cmd_line, cmdstr);
 567                 free(G.add_cmd_line);
 568                 cmdstr = G.add_cmd_line = tp;
 569         }
 570
 571         /* If this line ends with unescaped backslash, request next line. */
 572         n = len = strlen(cmdstr);
 573         while (n && cmdstr[n-1] == '\\')
 574                 n--;
 575         if ((len - n) & 1) { /* if odd number of trailing backslashes */
 576                 if (!G.add_cmd_line)
 577                         G.add_cmd_line = xstrdup(cmdstr);
 578                 G.add_cmd_line[len-1] = '\0';
 579                 return;
 580         }
 581
 582         /* Loop parsing all commands in this line. */
 583         while (*cmdstr) {
 584                 /* Skip leading whitespace and semicolons */
 585                 cmdstr += strspn(cmdstr, semicolon_whitespace);
 586
 587                 /* If no more commands, exit. */
 588                 if (!*cmdstr) break;
 589
 590                 /* if this is a comment, jump past it and keep going */
 591                 if (*cmdstr == '#') {
 592                         /* "#n" is the same as using -n on the command line */
 593                         if (cmdstr[1] == 'n')
 594                                 G.be_quiet++;
 595                         cmdstr = strpbrk(cmdstr, "\n\r");
 596                         if (!cmdstr) break;
 597                         continue;
 598                 }
 599
 600                 /* parse the command
 601                  * format is: [addr][,addr][!]cmd
 602                  *            |----||-----||-|
 603                  *            part1 part2  part3
 604                  */
 605
 606                 sed_cmd = xzalloc(sizeof(sed_cmd_t));
 607
 608                 /* first part (if present) is an address: either a '$', a number or a /regex/ */
 609                 cmdstr += get_address(cmdstr, &sed_cmd->beg_line, &sed_cmd->beg_match);
 610                 sed_cmd->beg_line_orig = sed_cmd->beg_line;
 611
 612                 /* second part (if present) will begin with a comma */
 613                 if (*cmdstr == ',') {
 614                         int idx;
 615
 616                         cmdstr++;
 617                         idx = get_address(cmdstr, &sed_cmd->end_line, &sed_cmd->end_match);
 618                         if (!idx)
 619                                 bb_error_msg_and_die("no address after comma");
 620                         cmdstr += idx;
 621                 }
 622
 623                 /* skip whitespace before the command */
 624                 cmdstr = skip_whitespace(cmdstr);
 625
 626                 /* Check for inversion flag */
 627                 if (*cmdstr == '!') {
 628                         sed_cmd->invert = 1;
 629                         cmdstr++;
 630
 631                         /* skip whitespace before the command */
 632                         cmdstr = skip_whitespace(cmdstr);
 633                 }
 634
 635                 /* last part (mandatory) will be a command */
 636                 if (!*cmdstr)
 637                         bb_error_msg_and_die("missing command");
 638                 sed_cmd->cmd = *cmdstr++;
 639                 cmdstr = parse_cmd_args(sed_cmd, cmdstr);
 640
 641                 /* Add the command to the command array */
 642                 *G.sed_cmd_tail = sed_cmd;
 643                 G.sed_cmd_tail = &sed_cmd->next;
 644         }
 645
 646         /* If we glued multiple lines together, free the memory. */
 647         free(G.add_cmd_line);
 648         G.add_cmd_line = NULL;
 649 }
 650
 651 /* Append to a string, reallocating memory as necessary. */
 652
 653 #define PIPE_GROW 64
 654
 655 static void pipe_putc(char c)
 656 {
 657         if (G.pipeline.idx == G.pipeline.len) {
 658                 G.pipeline.buf = xrealloc(G.pipeline.buf,
 659                                 G.pipeline.len + PIPE_GROW);
 660                 G.pipeline.len += PIPE_GROW;
 661         }
 662         G.pipeline.buf[G.pipeline.idx++] = c;
 663 }
 664
 665 static void do_subst_w_backrefs(char *line, char *replace)
 666 {
 667         int i, j;
 668
 669         /* go through the replacement string */
 670         for (i = 0; replace[i]; i++) {
 671                 /* if we find a backreference (\1, \2, etc.) print the backref'ed * text */
 672                 if (replace[i] == '\\') {
 673                         unsigned backref = replace[++i] - '0';
 674                         if (backref <= 9) {
 675                                 /* print out the text held in G.regmatch[backref] */
 676                                 if (G.regmatch[backref].rm_so != -1) {
 677                                         j = G.regmatch[backref].rm_so;
 678                                         while (j < G.regmatch[backref].rm_eo)
 679                                                 pipe_putc(line[j++]);
 680                                 }
 681                                 continue;
 682                         }
 683                         /* I _think_ it is impossible to get '\' to be
 684                          * the last char in replace string. Thus we dont check
 685                          * for replace[i] == NUL. (counterexample anyone?) */
 686                         /* if we find a backslash escaped character, print the character */
 687                         pipe_putc(replace[i]);
 688                         continue;
 689                 }
 690                 /* if we find an unescaped '&' print out the whole matched text. */
 691                 if (replace[i] == '&') {
 692                         j = G.regmatch[0].rm_so;
 693                         while (j < G.regmatch[0].rm_eo)
 694                                 pipe_putc(line[j++]);
 695                         continue;
 696                 }
 697                 /* Otherwise just output the character. */
 698                 pipe_putc(replace[i]);
 699         }
 700 }
 701
 702 static int do_subst_command(sed_cmd_t *sed_cmd, char **line_p)
 703 {
 704         char *line = *line_p;
 705         int altered = 0;
 706         unsigned match_count = 0;
 707         regex_t *current_regex;
 708
 709         current_regex = sed_cmd->sub_match;
 710         /* Handle empty regex. */
 711         if (!current_regex) {
 712                 current_regex = G.previous_regex_ptr;
 713                 if (!current_regex)
 714                         bb_error_msg_and_die("no previous regexp");
 715         }
 716         G.previous_regex_ptr = current_regex;
 717
 718         /* Find the first match */
 719         if (REG_NOMATCH == regexec(current_regex, line, 10, G.regmatch, 0))
 720                 return 0;
 721
 722         /* Initialize temporary output buffer. */
 723         G.pipeline.buf = xmalloc(PIPE_GROW);
 724         G.pipeline.len = PIPE_GROW;
 725         G.pipeline.idx = 0;
 726
 727         /* Now loop through, substituting for matches */
 728         do {
 729                 int i;
 730
 731                 /* Work around bug in glibc regexec, demonstrated by:
 732                    echo " a.b" | busybox sed 's [^ .]* x g'
 733                    The match_count check is so not to break
 734                    echo "hi" | busybox sed 's/^/!/g' */
 735                 if (!G.regmatch[0].rm_so && !G.regmatch[0].rm_eo && match_count) {
 736                         pipe_putc(*line++);
 737                         continue;
 738                 }
 739
 740                 match_count++;
 741
 742                 /* If we aren't interested in this match, output old line to
 743                    end of match and continue */
 744                 if (sed_cmd->which_match
 745                  && (sed_cmd->which_match != match_count)
 746                 ) {
 747                         for (i = 0; i < G.regmatch[0].rm_eo; i++)
 748                                 pipe_putc(*line++);
 749                         continue;
 750                 }
 751
 752                 /* print everything before the match */
 753                 for (i = 0; i < G.regmatch[0].rm_so; i++)
 754                         pipe_putc(line[i]);
 755
 756                 /* then print the substitution string */
 757                 do_subst_w_backrefs(line, sed_cmd->string);
 758
 759                 /* advance past the match */
 760                 line += G.regmatch[0].rm_eo;
 761                 /* flag that something has changed */
 762                 altered++;
 763
 764                 /* if we're not doing this globally, get out now */
 765                 if (sed_cmd->which_match)
 766                         break;
 767
 768 //maybe (G.regmatch[0].rm_eo ? REG_NOTBOL : 0) instead of unconditional REG_NOTBOL?
 769         } while (*line && regexec(current_regex, line, 10, G.regmatch, REG_NOTBOL) != REG_NOMATCH);
 770
 771         /* Copy rest of string into output pipeline */
 772         while (1) {
 773                 char c = *line++;
 774                 pipe_putc(c);
 775                 if (c == '\0')
 776                         break;
 777         }
 778
 779         free(*line_p);
 780         *line_p = G.pipeline.buf;
 781         return altered;
 782 }
 783
 784 /* Set command pointer to point to this label.  (Does not handle null label.) */
 785 static sed_cmd_t *branch_to(char *label)
 786 {
 787         sed_cmd_t *sed_cmd;
 788
 789         for (sed_cmd = G.sed_cmd_head; sed_cmd; sed_cmd = sed_cmd->next) {
 790                 if (sed_cmd->cmd == ':' && sed_cmd->string && !strcmp(sed_cmd->string, label)) {
 791                         return sed_cmd;
 792                 }
 793         }
 794         bb_error_msg_and_die("can't find label for jump to '%s'", label);
 795 }
 796
 797 static void append(char *s)
 798 {
 799         llist_add_to_end(&G.append_head, xstrdup(s));
 800 }
 801
 802 static void flush_append(void)
 803 {
 804         char *data;
 805
 806         /* Output appended lines. */
 807         while ((data = (char *)llist_pop(&G.append_head))) {
 808                 fprintf(G.nonstdout, "%s\n", data);
 809                 free(data);
 810         }
 811 }
 812
 813 static void add_input_file(FILE *file)
 814 {
 815         G.input_file_list = xrealloc_vector(G.input_file_list, 2, G.input_file_count);
 816         G.input_file_list[G.input_file_count++] = file;
 817 }
 818
 819 /* Get next line of input from G.input_file_list, flushing append buffer and
 820  * noting if we ran out of files without a newline on the last line we read.
 821  */
 822 enum {
 823         NO_EOL_CHAR = 1,
 824         LAST_IS_NUL = 2,
 825 };
 826 static char *get_next_line(char *gets_char)
 827 {
 828         char *temp = NULL;
 829         int len;
 830         char gc;
 831
 832         flush_append();
 833
 834         /* will be returned if last line in the file
 835          * doesn't end with either '\n' or '\0' */
 836         gc = NO_EOL_CHAR;
 837         while (G.current_input_file < G.input_file_count) {
 838                 FILE *fp = G.input_file_list[G.current_input_file];
 839                 /* Read line up to a newline or NUL byte, inclusive,
 840                  * return malloc'ed char[]. length of the chunk read
 841                  * is stored in len. NULL if EOF/error */
 842                 temp = bb_get_chunk_from_file(fp, &len);
 843                 if (temp) {
 844                         /* len > 0 here, it's ok to do temp[len-1] */
 845                         char c = temp[len-1];
 846                         if (c == '\n' || c == '\0') {
 847                                 temp[len-1] = '\0';
 848                                 gc = c;
 849                                 if (c == '\0') {
 850                                         int ch = fgetc(fp);
 851                                         if (ch != EOF)
 852                                                 ungetc(ch, fp);
 853                                         else
 854                                                 gc = LAST_IS_NUL;
 855                                 }
 856                         }
 857                         /* else we put NO_EOL_CHAR into *gets_char */
 858                         break;
 859
 860                 /* NB: I had the idea of peeking next file(s) and returning
 861                  * NO_EOL_CHAR only if it is the *last* non-empty
 862                  * input file. But there is a case where this won't work:
 863                  * file1: "a woo\nb woo"
 864                  * file2: "c no\nd no"
 865                  * sed -ne 's/woo/bang/p' input1 input2 => "a bang\nb bang"
 866                  * (note: *no* newline after "b bang"!) */
 867                 }
 868                 /* Close this file and advance to next one */
 869                 fclose(fp);
 870                 G.current_input_file++;
 871         }
 872         *gets_char = gc;
 873         return temp;
 874 }
 875
 876 /* Output line of text. */
 877 /* Note:
 878  * The tricks with NO_EOL_CHAR and last_puts_char are there to emulate gnu sed.
 879  * Without them, we had this:
 880  * echo -n thingy >z1
 881  * echo -n again >z2
 882  * >znull
 883  * sed "s/i/z/" z1 z2 znull | hexdump -vC
 884  * output:
 885  * gnu sed 4.1.5:
 886  * 00000000  74 68 7a 6e 67 79 0a 61  67 61 7a 6e              |thzngy.agazn|
 887  * bbox:
 888  * 00000000  74 68 7a 6e 67 79 61 67  61 7a 6e                 |thzngyagazn|
 889  */
 890 static void puts_maybe_newline(char *s, FILE *file, char *last_puts_char, char last_gets_char)
 891 {
 892         char lpc = *last_puts_char;
 893
 894         /* Need to insert a '\n' between two files because first file's
 895          * last line wasn't terminated? */
 896         if (lpc != '\n' && lpc != '\0') {
 897                 fputc('\n', file);
 898                 lpc = '\n';
 899         }
 900         fputs(s, file);
 901
 902         /* 'x' - just something which is not '\n', '\0' or NO_EOL_CHAR */
 903         if (s[0])
 904                 lpc = 'x';
 905
 906         /* had trailing '\0' and it was last char of file? */
 907         if (last_gets_char == LAST_IS_NUL) {
 908                 fputc('\0', file);
 909                 lpc = 'x'; /* */
 910         } else
 911         /* had trailing '\n' or '\0'? */
 912         if (last_gets_char != NO_EOL_CHAR) {
 913                 fputc(last_gets_char, file);
 914                 lpc = last_gets_char;
 915         }
 916
 917         if (ferror(file)) {
 918                 xfunc_error_retval = 4;  /* It's what gnu sed exits with... */
 919                 bb_error_msg_and_die(bb_msg_write_error);
 920         }
 921         *last_puts_char = lpc;
 922 }
 923
 924 #define sed_puts(s, n) (puts_maybe_newline(s, G.nonstdout, &last_puts_char, n))
 925
 926 static int beg_match(sed_cmd_t *sed_cmd, const char *pattern_space)
 927 {
 928         int retval = sed_cmd->beg_match && !regexec(sed_cmd->beg_match, pattern_space, 0, NULL, 0);
 929         if (retval)
 930                 G.previous_regex_ptr = sed_cmd->beg_match;
 931         return retval;
 932 }
 933
 934 /* Process all the lines in all the files */
 935
 936 static void process_files(void)
 937 {
 938         char *pattern_space, *next_line;
 939         int linenum = 0;
 940         char last_puts_char = '\n';
 941         char last_gets_char, next_gets_char;
 942         sed_cmd_t *sed_cmd;
 943         int substituted;
 944
 945         /* Prime the pump */
 946         next_line = get_next_line(&next_gets_char);
 947
 948         /* Go through every line in each file */
 949  again:
 950         substituted = 0;
 951
 952         /* Advance to next line.  Stop if out of lines. */
 953         pattern_space = next_line;
 954         if (!pattern_space)
 955                 return;
 956         last_gets_char = next_gets_char;
 957
 958         /* Read one line in advance so we can act on the last line,
 959          * the '$' address */
 960         next_line = get_next_line(&next_gets_char);
 961         linenum++;
 962
 963         /* For every line, go through all the commands */
 964  restart:
 965         for (sed_cmd = G.sed_cmd_head; sed_cmd; sed_cmd = sed_cmd->next) {
 966                 int old_matched, matched;
 967
 968                 old_matched = sed_cmd->in_match;
 969
 970                 /* Determine if this command matches this line: */
 971
 972                 dbg("match1:%d", sed_cmd->in_match);
 973                 dbg("match2:%d", (!sed_cmd->beg_line && !sed_cmd->end_line
 974                                 && !sed_cmd->beg_match && !sed_cmd->end_match));
 975                 dbg("match3:%d", (sed_cmd->beg_line > 0
 976                         && (sed_cmd->end_line || sed_cmd->end_match
 977                             ? (sed_cmd->beg_line <= linenum)
 978                             : (sed_cmd->beg_line == linenum)
 979                             )
 980                         ));
 981                 dbg("match4:%d", (beg_match(sed_cmd, pattern_space)));
 982                 dbg("match5:%d", (sed_cmd->beg_line == -1 && next_line == NULL));
 983
 984                 /* Are we continuing a previous multi-line match? */
 985                 sed_cmd->in_match = sed_cmd->in_match
 986                         /* Or is no range necessary? */
 987                         || (!sed_cmd->beg_line && !sed_cmd->end_line
 988                                 && !sed_cmd->beg_match && !sed_cmd->end_match)
 989                         /* Or did we match the start of a numerical range? */
 990                         || (sed_cmd->beg_line > 0
 991                             && (sed_cmd->end_line || sed_cmd->end_match
 992                                   /* note: even if end is numeric and is < linenum too,
 993                                    * GNU sed matches! We match too, therefore we don't
 994                                    * check here that linenum <= end.
 995                                    * Example:
 996                                    * printf '1\n2\n3\n4\n' | sed -n '1{N;N;d};1p;2,3p;3p;4p'
 997                                    * first three input lines are deleted;
 998                                    * 4th line is matched and printed
 999                                    * by "2,3" (!) and by "4" ranges
1000                                    */
1001                                 ? (sed_cmd->beg_line <= linenum)    /* N,end */
1002                                 : (sed_cmd->beg_line == linenum)    /* N */
1003                                 )
1004                             )
1005                         /* Or does this line match our begin address regex? */
1006                         || (beg_match(sed_cmd, pattern_space))
1007                         /* Or did we match last line of input? */
1008                         || (sed_cmd->beg_line == -1 && next_line == NULL);
1009
1010                 /* Snapshot the value */
1011                 matched = sed_cmd->in_match;
1012
1013                 dbg("cmd:'%c' matched:%d beg_line:%d end_line:%d linenum:%d",
1014                         sed_cmd->cmd, matched, sed_cmd->beg_line, sed_cmd->end_line, linenum);
1015
1016                 /* Is this line the end of the current match? */
1017
1018                 if (matched) {
1019                         /* once matched, "n,xxx" range is dead, disabling it */
1020                         if (sed_cmd->beg_line > 0) {
1021                                 sed_cmd->beg_line = -2;
1022                         }
1023                         sed_cmd->in_match = !(
1024                                 /* has the ending line come, or is this a single address command? */
1025                                 (sed_cmd->end_line
1026                                         ? sed_cmd->end_line == -1
1027                                                 ? !next_line
1028                                                 : (sed_cmd->end_line <= linenum)
1029                                         : !sed_cmd->end_match
1030                                 )
1031                                 /* or does this line matches our last address regex */
1032                                 || (sed_cmd->end_match && old_matched
1033                                      && (regexec(sed_cmd->end_match,
1034                                                  pattern_space, 0, NULL, 0) == 0)
1035                                 )
1036                         );
1037                 }
1038
1039                 /* Skip blocks of commands we didn't match */
1040                 if (sed_cmd->cmd == '{') {
1041                         if (sed_cmd->invert ? matched : !matched) {
1042                                 unsigned nest_cnt = 0;
1043                                 while (1) {
1044                                         if (sed_cmd->cmd == '{')
1045                                                 nest_cnt++;
1046                                         if (sed_cmd->cmd == '}') {
1047                                                 nest_cnt--;
1048                                                 if (nest_cnt == 0)
1049                                                         break;
1050                                         }
1051                                         sed_cmd = sed_cmd->next;
1052                                         if (!sed_cmd)
1053                                                 bb_error_msg_and_die("unterminated {");
1054                                 }
1055                         }
1056                         continue;
1057                 }
1058
1059                 /* Okay, so did this line match? */
1060                 if (sed_cmd->invert ? matched : !matched)
1061                         continue; /* no */
1062
1063                 /* Update last used regex in case a blank substitute BRE is found */
1064                 if (sed_cmd->beg_match) {
1065                         G.previous_regex_ptr = sed_cmd->beg_match;
1066                 }
1067
1068                 /* actual sedding */
1069                 //bb_error_msg("pattern_space:'%s' next_line:'%s' cmd:%c",
1070                 //pattern_space, next_line, sed_cmd->cmd);
1071                 switch (sed_cmd->cmd) {
1072
1073                 /* Print line number */
1074                 case '=':
1075                         fprintf(G.nonstdout, "%d\n", linenum);
1076                         break;
1077
1078                 /* Write the current pattern space up to the first newline */
1079                 case 'P':
1080                 {
1081                         char *tmp = strchr(pattern_space, '\n');
1082                         if (tmp) {
1083                                 *tmp = '\0';
1084                                 /* TODO: explain why '\n' below */
1085                                 sed_puts(pattern_space, '\n');
1086                                 *tmp = '\n';
1087                                 break;
1088                         }
1089                         /* Fall Through */
1090                 }
1091
1092                 /* Write the current pattern space to output */
1093                 case 'p':
1094                         /* NB: we print this _before_ the last line
1095                          * (of current file) is printed. Even if
1096                          * that line is nonterminated, we print
1097                          * '\n' here (gnu sed does the same) */
1098                         sed_puts(pattern_space, '\n');
1099                         break;
1100                 /* Delete up through first newline */
1101                 case 'D':
1102                 {
1103                         char *tmp = strchr(pattern_space, '\n');
1104                         if (tmp) {
1105                                 overlapping_strcpy(pattern_space, tmp + 1);
1106                                 goto restart;
1107                         }
1108                 }
1109                 /* discard this line. */
1110                 case 'd':
1111                         goto discard_line;
1112
1113                 /* Substitute with regex */
1114                 case 's':
1115                         if (!do_subst_command(sed_cmd, &pattern_space))
1116                                 break;
1117                         substituted |= 1;
1118
1119                         /* handle p option */
1120                         if (sed_cmd->sub_p)
1121                                 sed_puts(pattern_space, last_gets_char);
1122                         /* handle w option */
1123                         if (sed_cmd->sw_file)
1124                                 puts_maybe_newline(
1125                                         pattern_space, sed_cmd->sw_file,
1126                                         &sed_cmd->sw_last_char, last_gets_char);
1127                         break;
1128
1129                 /* Append line to linked list to be printed later */
1130                 case 'a':
1131                         append(sed_cmd->string);
1132                         break;
1133
1134                 /* Insert text before this line */
1135                 case 'i':
1136                         sed_puts(sed_cmd->string, '\n');
1137                         break;
1138
1139                 /* Cut and paste text (replace) */
1140                 case 'c':
1141                         /* Only triggers on last line of a matching range. */
1142                         if (!sed_cmd->in_match)
1143                                 sed_puts(sed_cmd->string, '\n');
1144                         goto discard_line;
1145
1146                 /* Read file, append contents to output */
1147                 case 'r':
1148                 {
1149                         FILE *rfile;
1150                         rfile = fopen_for_read(sed_cmd->string);
1151                         if (rfile) {
1152                                 char *line;
1153
1154                                 while ((line = xmalloc_fgetline(rfile))
1155                                                 != NULL)
1156                                         append(line);
1157                                 xprint_and_close_file(rfile);
1158                         }
1159
1160                         break;
1161                 }
1162
1163                 /* Write pattern space to file. */
1164                 case 'w':
1165                         puts_maybe_newline(
1166                                 pattern_space, sed_cmd->sw_file,
1167                                 &sed_cmd->sw_last_char, last_gets_char);
1168                         break;
1169
1170                 /* Read next line from input */
1171                 case 'n':
1172                         if (!G.be_quiet)
1173                                 sed_puts(pattern_space, last_gets_char);
1174                         if (next_line) {
1175                                 free(pattern_space);
1176                                 pattern_space = next_line;
1177                                 last_gets_char = next_gets_char;
1178                                 next_line = get_next_line(&next_gets_char);
1179                                 substituted = 0;
1180                                 linenum++;
1181                                 break;
1182                         }
1183                         /* fall through */
1184
1185                 /* Quit.  End of script, end of input. */
1186                 case 'q':
1187                         /* Exit the outer while loop */
1188                         free(next_line);
1189                         next_line = NULL;
1190                         goto discard_commands;
1191
1192                 /* Append the next line to the current line */
1193                 case 'N':
1194                 {
1195                         int len;
1196                         /* If no next line, jump to end of script and exit. */
1197                         /* http://www.gnu.org/software/sed/manual/sed.html:
1198                          * "Most versions of sed exit without printing anything
1199                          * when the N command is issued on the last line of
1200                          * a file. GNU sed prints pattern space before exiting
1201                          * unless of course the -n command switch has been
1202                          * specified. This choice is by design."
1203                          */
1204                         if (next_line == NULL) {
1205                                 //goto discard_line;
1206                                 goto discard_commands; /* GNU behavior */
1207                         }
1208                         /* Append next_line, read new next_line. */
1209                         len = strlen(pattern_space);
1210                         pattern_space = xrealloc(pattern_space, len + strlen(next_line) + 2);
1211                         pattern_space[len] = '\n';
1212                         strcpy(pattern_space + len+1, next_line);
1213                         last_gets_char = next_gets_char;
1214                         next_line = get_next_line(&next_gets_char);
1215                         linenum++;
1216                         break;
1217                 }
1218
1219                 /* Test/branch if substitution occurred */
1220                 case 't':
1221                         if (!substituted) break;
1222                         substituted = 0;
1223                         /* Fall through */
1224                 /* Test/branch if substitution didn't occur */
1225                 case 'T':
1226                         if (substituted) break;
1227                         /* Fall through */
1228                 /* Branch to label */
1229                 case 'b':
1230                         if (!sed_cmd->string) goto discard_commands;
1231                         else sed_cmd = branch_to(sed_cmd->string);
1232                         break;
1233                 /* Transliterate characters */
1234                 case 'y':
1235                 {
1236                         int i, j;
1237                         for (i = 0; pattern_space[i]; i++) {
1238                                 for (j = 0; sed_cmd->string[j]; j += 2) {
1239                                         if (pattern_space[i] == sed_cmd->string[j]) {
1240                                                 pattern_space[i] = sed_cmd->string[j + 1];
1241                                                 break;
1242                                         }
1243                                 }
1244                         }
1245
1246                         break;
1247                 }
1248                 case 'g':       /* Replace pattern space with hold space */
1249                         free(pattern_space);
1250                         pattern_space = xstrdup(G.hold_space ? G.hold_space : "");
1251                         break;
1252                 case 'G':       /* Append newline and hold space to pattern space */
1253                 {
1254                         int pattern_space_size = 2;
1255                         int hold_space_size = 0;
1256
1257                         if (pattern_space)
1258                                 pattern_space_size += strlen(pattern_space);
1259                         if (G.hold_space)
1260                                 hold_space_size = strlen(G.hold_space);
1261                         pattern_space = xrealloc(pattern_space,
1262                                         pattern_space_size + hold_space_size);
1263                         if (pattern_space_size == 2)
1264                                 pattern_space[0] = 0;
1265                         strcat(pattern_space, "\n");
1266                         if (G.hold_space)
1267                                 strcat(pattern_space, G.hold_space);
1268                         last_gets_char = '\n';
1269
1270                         break;
1271                 }
1272                 case 'h':       /* Replace hold space with pattern space */
1273                         free(G.hold_space);
1274                         G.hold_space = xstrdup(pattern_space);
1275                         break;
1276                 case 'H':       /* Append newline and pattern space to hold space */
1277                 {
1278                         int hold_space_size = 2;
1279                         int pattern_space_size = 0;
1280
1281                         if (G.hold_space)
1282                                 hold_space_size += strlen(G.hold_space);
1283                         if (pattern_space)
1284                                 pattern_space_size = strlen(pattern_space);
1285                         G.hold_space = xrealloc(G.hold_space,
1286                                         hold_space_size + pattern_space_size);
1287
1288                         if (hold_space_size == 2)
1289                                 *G.hold_space = 0;
1290                         strcat(G.hold_space, "\n");
1291                         if (pattern_space)
1292                                 strcat(G.hold_space, pattern_space);
1293
1294                         break;
1295                 }
1296                 case 'x': /* Exchange hold and pattern space */
1297                 {
1298                         char *tmp = pattern_space;
1299                         pattern_space = G.hold_space ? G.hold_space : xzalloc(1);
1300                         last_gets_char = '\n';
1301                         G.hold_space = tmp;
1302                         break;
1303                 }
1304                 } /* switch */
1305         } /* for each cmd */
1306
1307         /*
1308          * Exit point from sedding...
1309          */
1310  discard_commands:
1311         /* we will print the line unless we were told to be quiet ('-n')
1312            or if the line was suppressed (ala 'd'elete) */
1313         if (!G.be_quiet)
1314                 sed_puts(pattern_space, last_gets_char);
1315
1316         /* Delete and such jump here. */
1317  discard_line:
1318         flush_append();
1319         free(pattern_space);
1320
1321         goto again;
1322 }
1323
1324 /* It is possible to have a command line argument with embedded
1325  * newlines.  This counts as multiple command lines.
1326  * However, newline can be escaped: 's/e/z\<newline>z/'
1327  * We check for this.
1328  */
1329
1330 static void add_cmd_block(char *cmdstr)
1331 {
1332         char *sv, *eol;
1333
1334         cmdstr = sv = xstrdup(cmdstr);
1335         do {
1336                 eol = strchr(cmdstr, '\n');
1337  next:
1338                 if (eol) {
1339                         /* Count preceding slashes */
1340                         int slashes = 0;
1341                         char *sl = eol;
1342
1343                         while (sl != cmdstr && *--sl == '\\')
1344                                 slashes++;
1345                         /* Odd number of preceding slashes - newline is escaped */
1346                         if (slashes & 1) {
1347                                 overlapping_strcpy(eol - 1, eol);
1348                                 eol = strchr(eol, '\n');
1349                                 goto next;
1350                         }
1351                         *eol = '\0';
1352                 }
1353                 add_cmd(cmdstr);
1354                 cmdstr = eol + 1;
1355         } while (eol);
1356         free(sv);
1357 }
1358
1359 int sed_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1360 int sed_main(int argc UNUSED_PARAM, char **argv)
1361 {
1362         unsigned opt;
1363         llist_t *opt_e, *opt_f;
1364         int status = EXIT_SUCCESS;
1365
1366         INIT_G();
1367
1368         /* destroy command strings on exit */
1369         if (ENABLE_FEATURE_CLEAN_UP) atexit(sed_free_and_close_stuff);
1370
1371         /* Lie to autoconf when it starts asking stupid questions. */
1372         if (argv[1] && !strcmp(argv[1], "--version")) {
1373                 puts("This is not GNU sed version 4.0");
1374                 return 0;
1375         }
1376
1377         /* do normal option parsing */
1378         opt_e = opt_f = NULL;
1379         opt_complementary = "e::f::" /* can occur multiple times */
1380                             "nn"; /* count -n */
1381         /* -i must be first, to match OPT_in_place definition */
1382         opt = getopt32(argv, "irne:f:", &opt_e, &opt_f,
1383                             &G.be_quiet); /* counter for -n */
1384         //argc -= optind;
1385         argv += optind;
1386         if (opt & OPT_in_place) { // -i
1387                 atexit(cleanup_outname);
1388         }
1389         if (opt & 0x2) G.regex_type |= REG_EXTENDED; // -r
1390         //if (opt & 0x4) G.be_quiet++; // -n
1391         while (opt_e) { // -e
1392                 add_cmd_block(llist_pop(&opt_e));
1393         }
1394         while (opt_f) { // -f
1395                 char *line;
1396                 FILE *cmdfile;
1397                 cmdfile = xfopen_for_read(llist_pop(&opt_f));
1398                 while ((line = xmalloc_fgetline(cmdfile)) != NULL) {
1399                         add_cmd(line);
1400                         free(line);
1401                 }
1402                 fclose(cmdfile);
1403         }
1404         /* if we didn't get a pattern from -e or -f, use argv[0] */
1405         if (!(opt & 0x18)) {
1406                 if (!*argv)
1407                         bb_show_usage();
1408                 add_cmd_block(*argv++);
1409         }
1410         /* Flush any unfinished commands. */
1411         add_cmd("");
1412
1413         /* By default, we write to stdout */
1414         G.nonstdout = stdout;
1415
1416         /* argv[0..(argc-1)] should be names of file to process. If no
1417          * files were specified or '-' was specified, take input from stdin.
1418          * Otherwise, we process all the files specified. */
1419         if (argv[0] == NULL) {
1420                 if (opt & OPT_in_place)
1421                         bb_error_msg_and_die(bb_msg_requires_arg, "-i");
1422                 add_input_file(stdin);
1423         } else {
1424                 int i;
1425
1426                 for (i = 0; argv[i]; i++) {
1427                         struct stat statbuf;
1428                         int nonstdoutfd;
1429                         FILE *file;
1430                         sed_cmd_t *sed_cmd;
1431
1432                         if (LONE_DASH(argv[i]) && !(opt & OPT_in_place)) {
1433                                 add_input_file(stdin);
1434                                 process_files();
1435                                 continue;
1436                         }
1437                         file = fopen_or_warn(argv[i], "r");
1438                         if (!file) {
1439                                 status = EXIT_FAILURE;
1440                                 continue;
1441                         }
1442                         add_input_file(file);
1443                         if (!(opt & OPT_in_place)) {
1444                                 continue;
1445                         }
1446
1447                         /* -i: process each FILE separately: */
1448
1449                         G.outname = xasprintf("%sXXXXXX", argv[i]);
1450                         nonstdoutfd = xmkstemp(G.outname);
1451                         G.nonstdout = xfdopen_for_write(nonstdoutfd);
1452
1453                         /* Set permissions/owner of output file */
1454                         fstat(fileno(file), &statbuf);
1455                         /* chmod'ing AFTER chown would preserve suid/sgid bits,
1456                          * but GNU sed 4.2.1 does not preserve them either */
1457                         fchmod(nonstdoutfd, statbuf.st_mode);
1458                         fchown(nonstdoutfd, statbuf.st_uid, statbuf.st_gid);
1459
1460                         process_files();
1461                         fclose(G.nonstdout);
1462                         G.nonstdout = stdout;
1463
1464                         /* unlink(argv[i]); */
1465                         xrename(G.outname, argv[i]);
1466                         free(G.outname);
1467                         G.outname = NULL;
1468
1469                         /* Re-enable disabled range matches */
1470                         for (sed_cmd = G.sed_cmd_head; sed_cmd; sed_cmd = sed_cmd->next) {
1471                                 sed_cmd->beg_line = sed_cmd->beg_line_orig;
1472                         }
1473                 }
1474                 /* Here, to handle "sed 'cmds' nonexistent_file" case we did:
1475                  * if (G.current_input_file >= G.input_file_count)
1476                  *      return status;
1477                  * but it's not needed since process_files() works correctly
1478                  * in this case too. */
1479         }
1480         process_files();
1481
1482         return status;
1483 }