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 <bug1@iinet.net.au>
   9  * Copyright (C) 2003,2004 by Rob Landley <rob@landley.net>
  10  *
  11  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  12  */
  13
  14 /* Code overview.
  15
  16   Files are laid out to avoid unnecessary function declarations.  So for
  17   example, every function add_cmd calls occurs before add_cmd in this file.
  18
  19   add_cmd() is called on each line of sed command text (from a file or from
  20   the command line).  It calls get_address() and parse_cmd_args().  The
  21   resulting sed_cmd_t structures are appended to a linked list
  22   (sed_cmd_head/sed_cmd_tail).
  23
  24   add_input_file() adds a FILE * to the list of input files.  We need to
  25   know all input sources ahead of time to find the last line for the $ match.
  26
  27   process_files() does actual sedding, reading data lines from each input FILE *
  28   (which could be stdin) and applying the sed command list (sed_cmd_head) to
  29   each of the resulting lines.
  30
  31   sed_main() is where external code calls into this, with a command line.
  32 */
  33
  34
  35 /*
  36         Supported features and commands in this version of sed:
  37
  38          - comments ('#')
  39          - address matching: num|/matchstr/[,num|/matchstr/|$]command
  40          - commands: (p)rint, (d)elete, (s)ubstitue (with g & I flags)
  41          - edit commands: (a)ppend, (i)nsert, (c)hange
  42          - file commands: (r)ead
  43          - backreferences in substitution expressions (\0, \1, \2...\9)
  44          - grouped commands: {cmd1;cmd2}
  45          - transliteration (y/source-chars/dest-chars/)
  46          - pattern space hold space storing / swapping (g, h, x)
  47          - labels / branching (: label, b, t, T)
  48
  49          (Note: Specifying an address (range) to match is *optional*; commands
  50          default to the whole pattern space if no specific address match was
  51          requested.)
  52
  53         Todo:
  54          - Create a wrapper around regex to make libc's regex conform with sed
  55
  56         Reference http://www.opengroup.org/onlinepubs/007904975/utilities/sed.html
  57 */
  58
  59 #include <stdio.h>
  60 #include <unistd.h>             /* for getopt() */
  61 #include <string.h>             /* for strdup() */
  62 #include <errno.h>
  63 #include <ctype.h>              /* for isspace() */
  64 #include <stdlib.h>
  65 #include "busybox.h"
  66 #include "xregex.h"
  67
  68 typedef struct sed_cmd_s {
  69     /* Ordered by alignment requirements: currently 36 bytes on x86 */
  70
  71     /* address storage */
  72     regex_t *beg_match; /* sed -e '/match/cmd' */
  73     regex_t *end_match; /* sed -e '/match/,/end_match/cmd' */
  74     regex_t *sub_match; /* For 's/sub_match/string/' */
  75     int beg_line;               /* 'sed 1p'   0 == apply commands to all lines */
  76     int end_line;               /* 'sed 1,3p' 0 == one line only. -1 = last line ($) */
  77
  78     FILE *file;                 /* File (sr) command writes to, -1 for none. */
  79     char *string;               /* Data string for (saicytb) commands. */
  80
  81     unsigned short which_match;         /* (s) Which match to replace (0 for all) */
  82
  83     /* Bitfields (gcc won't group them if we don't) */
  84     unsigned int invert:1;                      /* the '!' after the address */
  85     unsigned int in_match:1;            /* Next line also included in match? */
  86     unsigned int no_newline:1;          /* Last line written by (sr) had no '\n' */
  87     unsigned int sub_p:1;                       /* (s) print option */
  88
  89
  90     /* GENERAL FIELDS */
  91     char cmd;                           /* The command char: abcdDgGhHilnNpPqrstwxy:={} */
  92     struct sed_cmd_s *next;     /* Next command (linked list, NULL terminated) */
  93 } sed_cmd_t;
  94
  95 /* globals */
  96 /* options */
  97 static int be_quiet, in_place, regex_type;
  98 static FILE *nonstdout;
  99 static char *outname,*hold_space;
 100
 101 /* List of input files */
 102 static int input_file_count,current_input_file;
 103 static FILE **input_file_list;
 104
 105 static const char bad_format_in_subst[] =
 106         "bad format in substitution expression";
 107 static const char *const semicolon_whitespace = "; \n\r\t\v";
 108
 109 static regmatch_t regmatch[10];
 110 static regex_t *previous_regex_ptr;
 111
 112 /* linked list of sed commands */
 113 static sed_cmd_t sed_cmd_head;
 114 static sed_cmd_t *sed_cmd_tail = &sed_cmd_head;
 115
 116 /* Linked list of append lines */
 117 struct append_list {
 118         char *string;
 119         struct append_list *next;
 120 };
 121 static struct append_list *append_head=NULL, *append_tail=NULL;
 122
 123 #ifdef CONFIG_FEATURE_CLEAN_UP
 124 static void free_and_close_stuff(void)
 125 {
 126         sed_cmd_t *sed_cmd = sed_cmd_head.next;
 127
 128         while(append_head) {
 129                 append_tail=append_head->next;
 130                 free(append_head->string);
 131                 free(append_head);
 132                 append_head=append_tail;
 133         }
 134
 135         while (sed_cmd) {
 136                 sed_cmd_t *sed_cmd_next = sed_cmd->next;
 137
 138                 if(sed_cmd->file)
 139                         bb_xprint_and_close_file(sed_cmd->file);
 140
 141                 if (sed_cmd->beg_match) {
 142                         regfree(sed_cmd->beg_match);
 143                         free(sed_cmd->beg_match);
 144                 }
 145                 if (sed_cmd->end_match) {
 146                         regfree(sed_cmd->end_match);
 147                         free(sed_cmd->end_match);
 148                 }
 149                 if (sed_cmd->sub_match) {
 150                         regfree(sed_cmd->sub_match);
 151                         free(sed_cmd->sub_match);
 152                 }
 153                 free(sed_cmd->string);
 154                 free(sed_cmd);
 155                 sed_cmd = sed_cmd_next;
 156         }
 157
 158         if(hold_space) free(hold_space);
 159
 160     while(current_input_file<input_file_count)
 161                 fclose(input_file_list[current_input_file++]);
 162 }
 163 #endif
 164
 165 /* If something bad happens during -i operation, delete temp file */
 166
 167 static void cleanup_outname(void)
 168 {
 169   if(outname) unlink(outname);
 170 }
 171
 172 /* strdup, replacing "\n" with '\n', and "\delimiter" with 'delimiter' */
 173
 174 static void parse_escapes(char *dest, const char *string, int len, char from, char to)
 175 {
 176         int i=0;
 177
 178         while(i<len) {
 179                 if(string[i] == '\\') {
 180                         if(!to || string[i+1] == from) {
 181                                 *(dest++) = to ? to : string[i+1];
 182                                 i+=2;
 183                                 continue;
 184                         } else *(dest++)=string[i++];
 185                 }
 186                 *(dest++) = string[i++];
 187         }
 188         *dest=0;
 189 }
 190
 191 static char *copy_parsing_escapes(const char *string, int len)
 192 {
 193         char *dest=xmalloc(len+1);
 194
 195         parse_escapes(dest,string,len,'n','\n');
 196         return dest;
 197 }
 198
 199
 200 /*
 201  * index_of_next_unescaped_regexp_delim - walks left to right through a string
 202  * beginning at a specified index and returns the index of the next regular
 203  * expression delimiter (typically a forward * slash ('/')) not preceded by
 204  * a backslash ('\').
 205  */
 206 static int index_of_next_unescaped_regexp_delim(const char delimiter,
 207         const char *str)
 208 {
 209         int bracket = -1;
 210         int escaped = 0;
 211         int idx = 0;
 212         char ch;
 213
 214         for (; (ch = str[idx]); idx++) {
 215                 if (bracket != -1) {
 216                         if (ch == ']' && !(bracket == idx - 1 || (bracket == idx - 2
 217                                         && str[idx - 1] == '^')))
 218                                 bracket = -1;
 219                 } else if (escaped)
 220                         escaped = 0;
 221                 else if (ch == '\\')
 222                         escaped = 1;
 223                 else if (ch == '[')
 224                         bracket = idx;
 225                 else if (ch == delimiter)
 226                         return idx;
 227         }
 228
 229         /* if we make it to here, we've hit the end of the string */
 230         return -1;
 231 }
 232
 233 /*
 234  *  Returns the index of the third delimiter
 235  */
 236 static int parse_regex_delim(const char *cmdstr, char **match, char **replace)
 237 {
 238         const char *cmdstr_ptr = cmdstr;
 239         char delimiter;
 240         int idx = 0;
 241
 242         /* verify that the 's' or 'y' is followed by something.  That something
 243          * (typically a 'slash') is now our regexp delimiter... */
 244         if (*cmdstr == '\0') bb_error_msg_and_die(bad_format_in_subst);
 245         delimiter = *(cmdstr_ptr++);
 246
 247         /* save the match string */
 248         idx = index_of_next_unescaped_regexp_delim(delimiter, cmdstr_ptr);
 249         if (idx == -1) {
 250                 bb_error_msg_and_die(bad_format_in_subst);
 251         }
 252         *match = copy_parsing_escapes(cmdstr_ptr, idx);
 253
 254         /* save the replacement string */
 255         cmdstr_ptr += idx + 1;
 256         idx = index_of_next_unescaped_regexp_delim(delimiter, cmdstr_ptr);
 257         if (idx == -1) {
 258                 bb_error_msg_and_die(bad_format_in_subst);
 259         }
 260         *replace = copy_parsing_escapes(cmdstr_ptr, idx);
 261
 262         return ((cmdstr_ptr - cmdstr) + idx);
 263 }
 264
 265 /*
 266  * returns the index in the string just past where the address ends.
 267  */
 268 static int get_address(char *my_str, int *linenum, regex_t ** regex)
 269 {
 270         char *pos = my_str;
 271
 272         if (isdigit(*my_str)) {
 273                 *linenum = strtol(my_str, &pos, 10);
 274                 /* endstr shouldnt ever equal NULL */
 275         } else if (*my_str == '$') {
 276                 *linenum = -1;
 277                 pos++;
 278         } else if (*my_str == '/' || *my_str == '\\') {
 279                 int next;
 280                 char delimiter;
 281                 char *temp;
 282
 283                 if (*my_str == '\\') delimiter = *(++pos);
 284                 else delimiter = '/';
 285                 next = index_of_next_unescaped_regexp_delim(delimiter, ++pos);
 286                 if (next == -1)
 287                         bb_error_msg_and_die("unterminated match expression");
 288
 289                 temp=copy_parsing_escapes(pos,next);
 290                 *regex = (regex_t *) xmalloc(sizeof(regex_t));
 291                 xregcomp(*regex, temp, regex_type|REG_NEWLINE);
 292                 free(temp);
 293                 /* Move position to next character after last delimiter */
 294                 pos+=(next+1);
 295         }
 296         return pos - my_str;
 297 }
 298
 299 /* Grab a filename.  Whitespace at start is skipped, then goes to EOL. */
 300 static int parse_file_cmd(sed_cmd_t * sed_cmd, const char *filecmdstr, char **retval)
 301 {
 302         int start = 0, idx, hack=0;
 303
 304         /* Skip whitespace, then grab filename to end of line */
 305         while (isspace(filecmdstr[start])) start++;
 306         idx=start;
 307         while(filecmdstr[idx] && filecmdstr[idx]!='\n') idx++;
 308         /* If lines glued together, put backslash back. */
 309         if(filecmdstr[idx]=='\n') hack=1;
 310         if(idx==start) bb_error_msg_and_die("Empty filename");
 311         *retval = bb_xstrndup(filecmdstr+start, idx-start+hack+1);
 312         if(hack) *(idx+*retval)='\\';
 313
 314         return idx;
 315 }
 316
 317 static int parse_subst_cmd(sed_cmd_t * const sed_cmd, char *substr)
 318 {
 319         int cflags = regex_type;
 320         char *match;
 321         int idx = 0;
 322
 323         /*
 324          * A substitution command should look something like this:
 325          *    s/match/replace/ #gIpw
 326          *    ||     |        |||
 327          *    mandatory       optional
 328          */
 329         idx = parse_regex_delim(substr, &match, &sed_cmd->string);
 330
 331         /* determine the number of back references in the match string */
 332         /* Note: we compute this here rather than in the do_subst_command()
 333          * function to save processor time, at the expense of a little more memory
 334          * (4 bits) per sed_cmd */
 335
 336         /* process the flags */
 337
 338         sed_cmd->which_match=1;
 339         while (substr[++idx]) {
 340                 /* Parse match number */
 341                 if(isdigit(substr[idx])) {
 342                         if(match[0]!='^') {
 343                                 /* Match 0 treated as all, multiple matches we take the last one. */
 344                                 char *pos=substr+idx;
 345                                 sed_cmd->which_match=(unsigned short)strtol(substr+idx,&pos,10);
 346                                 idx=pos-substr;
 347                         }
 348                         continue;
 349                 }
 350                 /* Skip spaces */
 351                 if(isspace(substr[idx])) continue;
 352
 353                 switch (substr[idx]) {
 354                         /* Replace all occurrences */
 355                         case 'g':
 356                                 if (match[0] != '^') sed_cmd->which_match = 0;
 357                                 break;
 358                         /* Print pattern space */
 359                         case 'p':
 360                                 sed_cmd->sub_p = 1;
 361                                 break;
 362                         /* Write to file */
 363                         case 'w':
 364                         {
 365                                 char *temp;
 366                                 idx+=parse_file_cmd(sed_cmd,substr+idx,&temp);
 367
 368                                 break;
 369                         }
 370                         /* Ignore case (gnu exension) */
 371                         case 'I':
 372                                 cflags |= REG_ICASE;
 373                                 break;
 374                         /* Comment */
 375                         case '#':
 376                                 while(substr[++idx]);
 377                                 /* Fall through */
 378                         /* End of command */
 379                         case ';':
 380                         case '}':
 381                                 goto out;
 382                         default:
 383                                 bb_error_msg_and_die("bad option in substitution expression");
 384                 }
 385         }
 386 out:
 387         /* compile the match string into a regex */
 388         if (*match != '\0') {
 389                 /* If match is empty, we use last regex used at runtime */
 390                 sed_cmd->sub_match = (regex_t *) xmalloc(sizeof(regex_t));
 391                 xregcomp(sed_cmd->sub_match, match, cflags);
 392         }
 393         free(match);
 394
 395         return idx;
 396 }
 397
 398 /*
 399  *  Process the commands arguments
 400  */
 401 static char *parse_cmd_args(sed_cmd_t *sed_cmd, char *cmdstr)
 402 {
 403         /* handle (s)ubstitution command */
 404         if (sed_cmd->cmd == 's') cmdstr += parse_subst_cmd(sed_cmd, cmdstr);
 405         /* handle edit cmds: (a)ppend, (i)nsert, and (c)hange */
 406         else if (strchr("aic", sed_cmd->cmd)) {
 407                 if ((sed_cmd->end_line || sed_cmd->end_match) && sed_cmd->cmd != 'c')
 408                         bb_error_msg_and_die
 409                                 ("only a beginning address can be specified for edit commands");
 410                 for(;;) {
 411                         if(*cmdstr=='\n' || *cmdstr=='\\') {
 412                                 cmdstr++;
 413                                 break;
 414                         } else if(isspace(*cmdstr)) cmdstr++;
 415                         else break;
 416                 }
 417                 sed_cmd->string = bb_xstrdup(cmdstr);
 418                 parse_escapes(sed_cmd->string,sed_cmd->string,strlen(cmdstr),0,0);
 419                 cmdstr += strlen(cmdstr);
 420         /* handle file cmds: (r)ead */
 421         } else if(strchr("rw", sed_cmd->cmd)) {
 422                 if (sed_cmd->end_line || sed_cmd->end_match)
 423                         bb_error_msg_and_die("Command only uses one address");
 424                 cmdstr += parse_file_cmd(sed_cmd, cmdstr, &sed_cmd->string);
 425                 if(sed_cmd->cmd=='w')
 426                         sed_cmd->file=bb_xfopen(sed_cmd->string,"w");
 427         /* handle branch commands */
 428         } else if (strchr(":btT", sed_cmd->cmd)) {
 429                 int length;
 430
 431                 while(isspace(*cmdstr)) cmdstr++;
 432                 length = strcspn(cmdstr, semicolon_whitespace);
 433                 if (length) {
 434                         sed_cmd->string = strndup(cmdstr, length);
 435                         cmdstr += length;
 436                 }
 437         }
 438         /* translation command */
 439         else if (sed_cmd->cmd == 'y') {
 440                 char *match, *replace;
 441                 int i=cmdstr[0];
 442
 443                 cmdstr+=parse_regex_delim(cmdstr, &match, &replace)+1;
 444                 /* \n already parsed, but \delimiter needs unescaping. */
 445                 parse_escapes(match,match,strlen(match),i,i);
 446                 parse_escapes(replace,replace,strlen(replace),i,i);
 447
 448                 sed_cmd->string = xcalloc(1, (strlen(match) + 1) * 2);
 449                 for (i = 0; match[i] && replace[i]; i++) {
 450                         sed_cmd->string[i * 2] = match[i];
 451                         sed_cmd->string[(i * 2) + 1] = replace[i];
 452                 }
 453                 free(match);
 454                 free(replace);
 455         }
 456         /* if it wasnt a single-letter command that takes no arguments
 457          * then it must be an invalid command.
 458          */
 459         else if (strchr("dDgGhHlnNpPqx={}", sed_cmd->cmd) == 0) {
 460                 bb_error_msg_and_die("Unsupported command %c", sed_cmd->cmd);
 461         }
 462
 463         /* give back whatever's left over */
 464         return (cmdstr);
 465 }
 466
 467
 468 /* Parse address+command sets, skipping comment lines. */
 469
 470 static void add_cmd(char *cmdstr)
 471 {
 472         static char *add_cmd_line=NULL;
 473         sed_cmd_t *sed_cmd;
 474         int temp;
 475
 476         /* Append this line to any unfinished line from last time. */
 477         if(add_cmd_line) {
 478                 int lastlen=strlen(add_cmd_line);
 479                 char *tmp=xmalloc(lastlen+strlen(cmdstr)+2);
 480
 481                 memcpy(tmp,add_cmd_line,lastlen);
 482                 tmp[lastlen]='\n';
 483                 strcpy(tmp+lastlen+1,cmdstr);
 484                 free(add_cmd_line);
 485                 cmdstr=add_cmd_line=tmp;
 486         } else add_cmd_line=NULL;
 487
 488         /* If this line ends with backslash, request next line. */
 489         temp=strlen(cmdstr);
 490         if(temp && cmdstr[temp-1]=='\\') {
 491                 if(!add_cmd_line) add_cmd_line=strdup(cmdstr);
 492                 add_cmd_line[temp-1]=0;
 493                 return;
 494         }
 495
 496         /* Loop parsing all commands in this line. */
 497         while(*cmdstr) {
 498                 /* Skip leading whitespace and semicolons */
 499                 cmdstr += strspn(cmdstr, semicolon_whitespace);
 500
 501                 /* If no more commands, exit. */
 502                 if(!*cmdstr) break;
 503
 504                 /* if this is a comment, jump past it and keep going */
 505                 if (*cmdstr == '#') {
 506                         /* "#n" is the same as using -n on the command line */
 507                         if (cmdstr[1] == 'n') be_quiet++;
 508                         if(!(cmdstr=strpbrk(cmdstr, "\n\r"))) break;
 509                         continue;
 510                 }
 511
 512                 /* parse the command
 513                  * format is: [addr][,addr][!]cmd
 514                  *            |----||-----||-|
 515                  *            part1 part2  part3
 516                  */
 517
 518                 sed_cmd = xcalloc(1, sizeof(sed_cmd_t));
 519
 520                 /* first part (if present) is an address: either a '$', a number or a /regex/ */
 521                 cmdstr += get_address(cmdstr, &sed_cmd->beg_line, &sed_cmd->beg_match);
 522
 523                 /* second part (if present) will begin with a comma */
 524                 if (*cmdstr == ',') {
 525                         int idx;
 526
 527                         cmdstr++;
 528                         idx = get_address(cmdstr, &sed_cmd->end_line, &sed_cmd->end_match);
 529                         if (!idx) bb_error_msg_and_die("get_address: no address found in string\n");
 530                         cmdstr += idx;
 531                 }
 532
 533                 /* skip whitespace before the command */
 534                 while (isspace(*cmdstr)) cmdstr++;
 535
 536                 /* Check for inversion flag */
 537                 if (*cmdstr == '!') {
 538                         sed_cmd->invert = 1;
 539                         cmdstr++;
 540
 541                         /* skip whitespace before the command */
 542                         while (isspace(*cmdstr)) cmdstr++;
 543                 }
 544
 545                 /* last part (mandatory) will be a command */
 546                 if (!*cmdstr) bb_error_msg_and_die("missing command");
 547                 sed_cmd->cmd = *(cmdstr++);
 548                 cmdstr = parse_cmd_args(sed_cmd, cmdstr);
 549
 550                 /* Add the command to the command array */
 551                 sed_cmd_tail->next = sed_cmd;
 552                 sed_cmd_tail = sed_cmd_tail->next;
 553         }
 554
 555         /* If we glued multiple lines together, free the memory. */
 556         if(add_cmd_line) {
 557                 free(add_cmd_line);
 558                 add_cmd_line=NULL;
 559         }
 560 }
 561
 562 /* Append to a string, reallocating memory as necessary. */
 563
 564 static struct pipeline {
 565         char *buf;      /* Space to hold string */
 566         int idx;        /* Space used */
 567         int len;        /* Space allocated */
 568 } pipeline;
 569
 570 #define PIPE_GROW 64
 571
 572 static void pipe_putc(char c)
 573 {
 574         if(pipeline.idx==pipeline.len) {
 575                 pipeline.buf = xrealloc(pipeline.buf, pipeline.len + PIPE_GROW);
 576                 pipeline.len+=PIPE_GROW;
 577         }
 578         pipeline.buf[pipeline.idx++] = (c);
 579 }
 580
 581 static void do_subst_w_backrefs(const char *line, const char *replace)
 582 {
 583         int i,j;
 584
 585         /* go through the replacement string */
 586         for (i = 0; replace[i]; i++) {
 587                 /* if we find a backreference (\1, \2, etc.) print the backref'ed * text */
 588                 if (replace[i] == '\\' && replace[i+1]>='0' && replace[i+1]<='9') {
 589                         int backref=replace[++i]-'0';
 590
 591                         /* print out the text held in regmatch[backref] */
 592                         if(regmatch[backref].rm_so != -1)
 593                                 for (j = regmatch[backref].rm_so; j < regmatch[backref].rm_eo; j++)
 594                                         pipe_putc(line[j]);
 595                 }
 596
 597                 /* if we find a backslash escaped character, print the character */
 598                 else if (replace[i] == '\\') pipe_putc(replace[++i]);
 599
 600                 /* if we find an unescaped '&' print out the whole matched text. */
 601                 else if (replace[i] == '&')
 602                         for (j = regmatch[0].rm_so; j < regmatch[0].rm_eo; j++)
 603                                 pipe_putc(line[j]);
 604                 /* Otherwise just output the character. */
 605                 else pipe_putc(replace[i]);
 606         }
 607 }
 608
 609 static int do_subst_command(sed_cmd_t * sed_cmd, char **line)
 610 {
 611         char *oldline = *line;
 612         int altered = 0;
 613         int match_count=0;
 614         regex_t *current_regex;
 615
 616         /* Handle empty regex. */
 617         if (sed_cmd->sub_match == NULL) {
 618                 current_regex = previous_regex_ptr;
 619                 if(!current_regex)
 620                         bb_error_msg_and_die("No previous regexp.");
 621         } else previous_regex_ptr = current_regex = sed_cmd->sub_match;
 622
 623         /* Find the first match */
 624         if(REG_NOMATCH==regexec(current_regex, oldline, 10, regmatch, 0))
 625                 return 0;
 626
 627         /* Initialize temporary output buffer. */
 628         pipeline.buf=xmalloc(PIPE_GROW);
 629         pipeline.len=PIPE_GROW;
 630         pipeline.idx=0;
 631
 632         /* Now loop through, substituting for matches */
 633         do {
 634                 int i;
 635
 636                 /* Work around bug in glibc regexec, demonstrated by:
 637                    echo " a.b" | busybox sed 's [^ .]* x g'
 638                    The match_count check is so not to break
 639                    echo "hi" | busybox sed 's/^/!/g' */
 640                 if(!regmatch[0].rm_so && !regmatch[0].rm_eo && match_count) {
 641                         pipe_putc(*(oldline++));
 642                         continue;
 643                 }
 644
 645                 match_count++;
 646
 647                 /* If we aren't interested in this match, output old line to
 648                    end of match and continue */
 649                 if(sed_cmd->which_match && sed_cmd->which_match!=match_count) {
 650                         for(i=0;i<regmatch[0].rm_eo;i++)
 651                                 pipe_putc(oldline[i]);
 652                         continue;
 653                 }
 654
 655                 /* print everything before the match */
 656                 for (i = 0; i < regmatch[0].rm_so; i++) pipe_putc(oldline[i]);
 657
 658                 /* then print the substitution string */
 659                 do_subst_w_backrefs(oldline, sed_cmd->string);
 660
 661                 /* advance past the match */
 662                 oldline += regmatch[0].rm_eo;
 663                 /* flag that something has changed */
 664                 altered++;
 665
 666                 /* if we're not doing this globally, get out now */
 667                 if (sed_cmd->which_match) break;
 668         } while (*oldline && (regexec(current_regex, oldline, 10, regmatch, 0) != REG_NOMATCH));
 669
 670         /* Copy rest of string into output pipeline */
 671
 672         while(*oldline) pipe_putc(*(oldline++));
 673         pipe_putc(0);
 674
 675         free(*line);
 676         *line = pipeline.buf;
 677         return altered;
 678 }
 679
 680 /* Set command pointer to point to this label.  (Does not handle null label.) */
 681 static sed_cmd_t *branch_to(const char *label)
 682 {
 683         sed_cmd_t *sed_cmd;
 684
 685         for (sed_cmd = sed_cmd_head.next; sed_cmd; sed_cmd = sed_cmd->next) {
 686                 if ((sed_cmd->cmd == ':') && (sed_cmd->string) && (strcmp(sed_cmd->string, label) == 0)) {
 687                         return (sed_cmd);
 688                 }
 689         }
 690         bb_error_msg_and_die("Can't find label for jump to `%s'", label);
 691 }
 692
 693 /* Append copy of string to append buffer */
 694 static void append(char *s)
 695 {
 696         struct append_list *temp=calloc(1,sizeof(struct append_list));
 697
 698         if(append_head)
 699                 append_tail=(append_tail->next=temp);
 700         else append_head=append_tail=temp;
 701         temp->string=strdup(s);
 702 }
 703
 704 static void flush_append(void)
 705 {
 706         /* Output appended lines. */
 707         while(append_head) {
 708                 fprintf(nonstdout,"%s\n",append_head->string);
 709                 append_tail=append_head->next;
 710                 free(append_head->string);
 711                 free(append_head);
 712                 append_head=append_tail;
 713         }
 714         append_head=append_tail=NULL;
 715 }
 716
 717 static void add_input_file(FILE *file)
 718 {
 719         input_file_list=xrealloc(input_file_list,(input_file_count+1)*sizeof(FILE *));
 720         input_file_list[input_file_count++]=file;
 721 }
 722
 723 /* Get next line of input from input_file_list, flushing append buffer and
 724  * noting if we ran out of files without a newline on the last line we read.
 725  */
 726 static char *get_next_line(int *no_newline)
 727 {
 728         char *temp=NULL;
 729         int len;
 730
 731         flush_append();
 732         while(current_input_file<input_file_count) {
 733                 temp=bb_get_line_from_file(input_file_list[current_input_file]);
 734                 if(temp) {
 735                         len=strlen(temp);
 736                         *no_newline=!(len && temp[len-1]=='\n');
 737                         if(!*no_newline) temp[len-1]=0;
 738                         break;
 739                 } else fclose(input_file_list[current_input_file++]);
 740         }
 741
 742         return temp;
 743 }
 744
 745 /* Output line of text.  missing_newline means the last line output did not
 746    end with a newline.  no_newline means this line does not end with a
 747    newline. */
 748
 749 static int puts_maybe_newline(char *s, FILE *file, int missing_newline, int no_newline)
 750 {
 751         if(missing_newline) fputc('\n',file);
 752         fputs(s,file);
 753         if(!no_newline) fputc('\n',file);
 754
 755     if(ferror(file)) {
 756                 fprintf(stderr,"Write failed.\n");
 757                 exit(4);  /* It's what gnu sed exits with... */
 758         }
 759
 760         return no_newline;
 761 }
 762
 763 #define sed_puts(s,n) missing_newline=puts_maybe_newline(s,nonstdout,missing_newline,n)
 764
 765 static void process_files(void)
 766 {
 767         char *pattern_space, *next_line;
 768         int linenum = 0, missing_newline=0;
 769         int no_newline,next_no_newline=0;
 770
 771         next_line = get_next_line(&next_no_newline);
 772
 773         /* go through every line in each file */
 774         for(;;) {
 775                 sed_cmd_t *sed_cmd;
 776                 int substituted=0;
 777
 778                 /* Advance to next line.  Stop if out of lines. */
 779                 if(!(pattern_space=next_line)) break;
 780                 no_newline=next_no_newline;
 781
 782                 /* Read one line in advance so we can act on the last line, the '$' address */
 783                 next_line = get_next_line(&next_no_newline);
 784                 linenum++;
 785 restart:
 786                 /* for every line, go through all the commands */
 787                 for (sed_cmd = sed_cmd_head.next; sed_cmd; sed_cmd = sed_cmd->next) {
 788                         int old_matched, matched;
 789
 790                         old_matched = sed_cmd->in_match;
 791
 792                         /* Determine if this command matches this line: */
 793
 794                         /* Are we continuing a previous multi-line match? */
 795
 796                         sed_cmd->in_match = sed_cmd->in_match
 797
 798                         /* Or is no range necessary? */
 799                                 || (!sed_cmd->beg_line && !sed_cmd->end_line
 800                                         && !sed_cmd->beg_match && !sed_cmd->end_match)
 801
 802                         /* Or did we match the start of a numerical range? */
 803                                 || (sed_cmd->beg_line > 0 && (sed_cmd->beg_line == linenum))
 804
 805                         /* Or does this line match our begin address regex? */
 806                                 || (sed_cmd->beg_match &&
 807                                     !regexec(sed_cmd->beg_match, pattern_space, 0, NULL, 0))
 808
 809                         /* Or did we match last line of input? */
 810                                 || (sed_cmd->beg_line == -1 && next_line == NULL);
 811
 812                         /* Snapshot the value */
 813
 814                         matched = sed_cmd->in_match;
 815
 816                         /* Is this line the end of the current match? */
 817
 818                         if(matched) {
 819                                 sed_cmd->in_match = !(
 820                                         /* has the ending line come, or is this a single address command? */
 821                                         (sed_cmd->end_line ?
 822                                                 sed_cmd->end_line==-1 ?
 823                                                         !next_line
 824                                                         : sed_cmd->end_line<=linenum
 825                                                 : !sed_cmd->end_match)
 826                                         /* or does this line matches our last address regex */
 827                                         || (sed_cmd->end_match && old_matched && (regexec(sed_cmd->end_match, pattern_space, 0, NULL, 0) == 0))
 828                                 );
 829                         }
 830
 831                         /* Skip blocks of commands we didn't match. */
 832                         if (sed_cmd->cmd == '{') {
 833                                 if(sed_cmd->invert ? matched : !matched)
 834                                         while(sed_cmd && sed_cmd->cmd!='}') sed_cmd=sed_cmd->next;
 835                                 if(!sed_cmd) bb_error_msg_and_die("Unterminated {");
 836                                 continue;
 837                         }
 838
 839                         /* Okay, so did this line match? */
 840                         if (sed_cmd->invert ? !matched : matched) {
 841                                 /* Update last used regex in case a blank substitute BRE is found */
 842                                 if (sed_cmd->beg_match) {
 843                                         previous_regex_ptr = sed_cmd->beg_match;
 844                                 }
 845
 846                                 /* actual sedding */
 847                                 switch (sed_cmd->cmd) {
 848
 849                                         /* Print line number */
 850                                         case '=':
 851                                                 fprintf(nonstdout,"%d\n", linenum);
 852                                                 break;
 853
 854                                         /* Write the current pattern space up to the first newline */
 855                                         case 'P':
 856                                         {
 857                                                 char *tmp = strchr(pattern_space, '\n');
 858
 859                                                 if (tmp) {
 860                                                         *tmp = '\0';
 861                                                         sed_puts(pattern_space,1);
 862                                                         *tmp = '\n';
 863                                                         break;
 864                                                 }
 865                                                 /* Fall Through */
 866                                         }
 867
 868                                         /* Write the current pattern space to output */
 869                                         case 'p':
 870                                                 sed_puts(pattern_space,no_newline);
 871                                                 break;
 872                                         /* Delete up through first newline */
 873                                         case 'D':
 874                                         {
 875                                                 char *tmp = strchr(pattern_space,'\n');
 876
 877                                                 if(tmp) {
 878                                                         tmp=bb_xstrdup(tmp+1);
 879                                                         free(pattern_space);
 880                                                         pattern_space=tmp;
 881                                                         goto restart;
 882                                                 }
 883                                         }
 884                                         /* discard this line. */
 885                                         case 'd':
 886                                                 goto discard_line;
 887
 888                                         /* Substitute with regex */
 889                                         case 's':
 890                                                 if(do_subst_command(sed_cmd, &pattern_space)) {
 891                                                         substituted|=1;
 892
 893                                                         /* handle p option */
 894                                                         if(sed_cmd->sub_p)
 895                                                                 sed_puts(pattern_space,no_newline);
 896                                                         /* handle w option */
 897                                                         if(sed_cmd->file)
 898                                                                 sed_cmd->no_newline=puts_maybe_newline(pattern_space, sed_cmd->file, sed_cmd->no_newline, no_newline);
 899
 900                                                 }
 901                                                 break;
 902
 903                                         /* Append line to linked list to be printed later */
 904                                         case 'a':
 905                                         {
 906                                                 append(sed_cmd->string);
 907                                                 break;
 908                                         }
 909
 910                                         /* Insert text before this line */
 911                                         case 'i':
 912                                                 sed_puts(sed_cmd->string,1);
 913                                                 break;
 914
 915                                         /* Cut and paste text (replace) */
 916                                         case 'c':
 917                                                 /* Only triggers on last line of a matching range. */
 918                                                 if (!sed_cmd->in_match) sed_puts(sed_cmd->string,0);
 919                                                 goto discard_line;
 920
 921                                         /* Read file, append contents to output */
 922                                         case 'r':
 923                                         {
 924                                                 FILE *outfile;
 925
 926                                                 outfile = fopen(sed_cmd->string, "r");
 927                                                 if (outfile) {
 928                                                         char *line;
 929
 930                                                         while ((line = bb_get_chomped_line_from_file(outfile))
 931                                                                         != NULL)
 932                                                                 append(line);
 933                                                         bb_xprint_and_close_file(outfile);
 934                                                 }
 935
 936                                                 break;
 937                                         }
 938
 939                                         /* Write pattern space to file. */
 940                                         case 'w':
 941                                                 sed_cmd->no_newline=puts_maybe_newline(pattern_space,sed_cmd->file, sed_cmd->no_newline,no_newline);
 942                                                 break;
 943
 944                                         /* Read next line from input */
 945                                         case 'n':
 946                                                 if (!be_quiet)
 947                                                         sed_puts(pattern_space,no_newline);
 948                                                 if (next_line) {
 949                                                         free(pattern_space);
 950                                                         pattern_space = next_line;
 951                                                         no_newline=next_no_newline;
 952                                                         next_line = get_next_line(&next_no_newline);
 953                                                         linenum++;
 954                                                         break;
 955                                                 }
 956                                                 /* fall through */
 957
 958                                         /* Quit.  End of script, end of input. */
 959                                         case 'q':
 960                                                 /* Exit the outer while loop */
 961                                                 free(next_line);
 962                                                 next_line = NULL;
 963                                                 goto discard_commands;
 964
 965                                         /* Append the next line to the current line */
 966                                         case 'N':
 967                                         {
 968                                                 /* If no next line, jump to end of script and exit. */
 969                                                 if (next_line == NULL) {
 970                                                         /* Jump to end of script and exit */
 971                                                         free(next_line);
 972                                                         next_line = NULL;
 973                                                         goto discard_line;
 974                                                 /* append next_line, read new next_line. */
 975                                                 } else {
 976                                                         int len=strlen(pattern_space);
 977
 978                                                         pattern_space = realloc(pattern_space, len + strlen(next_line) + 2);
 979                                                         pattern_space[len]='\n';
 980                                                         strcpy(pattern_space+len+1, next_line);
 981                                                         no_newline=next_no_newline;
 982                                                         next_line = get_next_line(&next_no_newline);
 983                                                         linenum++;
 984                                                 }
 985                                                 break;
 986                                         }
 987
 988                                         /* Test/branch if substitution occurred */
 989                                         case 't':
 990                                                 if(!substituted) break;
 991                                                 substituted=0;
 992                                                 /* Fall through */
 993                                         /* Test/branch if substitution didn't occur */
 994                                         case 'T':
 995                                                 if (substituted) break;
 996                                                 /* Fall through */
 997                                         /* Branch to label */
 998                                         case 'b':
 999                                                 if (!sed_cmd->string) goto discard_commands;
1000                                                 else sed_cmd = branch_to(sed_cmd->string);
1001                                                 break;
1002                                         /* Transliterate characters */
1003                                         case 'y':
1004                                         {
1005                                                 int i;
1006
1007                                                 for (i = 0; pattern_space[i]; i++) {
1008                                                         int j;
1009
1010                                                         for (j = 0; sed_cmd->string[j]; j += 2) {
1011                                                                 if (pattern_space[i] == sed_cmd->string[j]) {
1012                                                                         pattern_space[i] = sed_cmd->string[j + 1];
1013                                                                         break;
1014                                                                 }
1015                                                         }
1016                                                 }
1017
1018                                                 break;
1019                                         }
1020                                         case 'g':       /* Replace pattern space with hold space */
1021                                                 free(pattern_space);
1022                                                 pattern_space = strdup(hold_space ? hold_space : "");
1023                                                 break;
1024                                         case 'G':       /* Append newline and hold space to pattern space */
1025                                         {
1026                                                 int pattern_space_size = 2;
1027                                                 int hold_space_size = 0;
1028
1029                                                 if (pattern_space)
1030                                                         pattern_space_size += strlen(pattern_space);
1031                                                 if (hold_space) hold_space_size = strlen(hold_space);
1032                                                 pattern_space = xrealloc(pattern_space, pattern_space_size + hold_space_size);
1033                                                 if (pattern_space_size == 2) pattern_space[0]=0;
1034                                                 strcat(pattern_space, "\n");
1035                                                 if (hold_space) strcat(pattern_space, hold_space);
1036                                                 no_newline=0;
1037
1038                                                 break;
1039                                         }
1040                                         case 'h':       /* Replace hold space with pattern space */
1041                                                 free(hold_space);
1042                                                 hold_space = strdup(pattern_space);
1043                                                 break;
1044                                         case 'H':       /* Append newline and pattern space to hold space */
1045                                         {
1046                                                 int hold_space_size = 2;
1047                                                 int pattern_space_size = 0;
1048
1049                                                 if (hold_space) hold_space_size += strlen(hold_space);
1050                                                 if (pattern_space)
1051                                                         pattern_space_size = strlen(pattern_space);
1052                                                 hold_space = xrealloc(hold_space,
1053                                                                                         hold_space_size + pattern_space_size);
1054
1055                                                 if (hold_space_size == 2) hold_space[0]=0;
1056                                                 strcat(hold_space, "\n");
1057                                                 if (pattern_space) strcat(hold_space, pattern_space);
1058
1059                                                 break;
1060                                         }
1061                                         case 'x': /* Exchange hold and pattern space */
1062                                         {
1063                                                 char *tmp = pattern_space;
1064                                                 pattern_space = hold_space;
1065                                                 no_newline=0;
1066                                                 hold_space = tmp;
1067                                                 break;
1068                                         }
1069                                 }
1070                         }
1071                 }
1072
1073                 /*
1074                  * exit point from sedding...
1075                  */
1076 discard_commands:
1077                 /* we will print the line unless we were told to be quiet ('-n')
1078                    or if the line was suppressed (ala 'd'elete) */
1079                 if (!be_quiet) sed_puts(pattern_space,no_newline);
1080
1081                 /* Delete and such jump here. */
1082 discard_line:
1083                 flush_append();
1084                 free(pattern_space);
1085         }
1086 }
1087
1088 /* It is possible to have a command line argument with embedded
1089    newlines.  This counts as multiple command lines. */
1090
1091 static void add_cmd_block(char *cmdstr)
1092 {
1093         int go=1;
1094         char *temp=bb_xstrdup(cmdstr),*temp2=temp;
1095
1096         while(go) {
1097                 int len=strcspn(temp2,"\n");
1098                 if(!temp2[len]) go=0;
1099                 else temp2[len]=0;
1100                 add_cmd(temp2);
1101                 temp2+=len+1;
1102         }
1103         free(temp);
1104 }
1105
1106 extern int sed_main(int argc, char **argv)
1107 {
1108         int status = EXIT_SUCCESS, opt, getpat = 1;
1109
1110 #ifdef CONFIG_FEATURE_CLEAN_UP
1111         /* destroy command strings on exit */
1112         if (atexit(free_and_close_stuff) == -1)
1113                 bb_perror_msg_and_die("atexit");
1114 #endif
1115
1116         /* Lie to autoconf when it starts asking stupid questions. */
1117         if(argc==2 && !strcmp(argv[1],"--version")) {
1118                 printf("This is not GNU sed version 4.0\n");
1119                 exit(0);
1120         }
1121
1122         /* do normal option parsing */
1123         while ((opt = getopt(argc, argv, "irne:f:")) > 0) {
1124                 switch (opt) {
1125                 case 'i':
1126                         in_place++;
1127                         atexit(cleanup_outname);
1128                         break;
1129                 case 'r':
1130                         regex_type|=REG_EXTENDED;
1131                         break;
1132                 case 'n':
1133                         be_quiet++;
1134                         break;
1135                 case 'e':
1136                         add_cmd_block(optarg);
1137                         getpat=0;
1138                         break;
1139                 case 'f':
1140                 {
1141                         FILE *cmdfile;
1142                         char *line;
1143
1144                         cmdfile = bb_xfopen(optarg, "r");
1145
1146                         while ((line = bb_get_chomped_line_from_file(cmdfile)) != NULL) {
1147                                 add_cmd(line);
1148                                 getpat=0;
1149                                 free(line);
1150                         }
1151                         bb_xprint_and_close_file(cmdfile);
1152
1153                         break;
1154                 }
1155                 default:
1156                         bb_show_usage();
1157                 }
1158         }
1159
1160         /* if we didn't get a pattern from -e or -f, use argv[optind] */
1161         if(getpat) {
1162                 if (argv[optind] == NULL)
1163                         bb_show_usage();
1164                 else
1165                         add_cmd_block(argv[optind++]);
1166         }
1167         /* Flush any unfinished commands. */
1168         add_cmd("");
1169
1170         /* By default, we write to stdout */
1171         nonstdout=stdout;
1172
1173         /* argv[(optind)..(argc-1)] should be names of file to process. If no
1174          * files were specified or '-' was specified, take input from stdin.
1175          * Otherwise, we process all the files specified. */
1176         if (argv[optind] == NULL) {
1177                 if(in_place) bb_error_msg_and_die("Filename required for -i");
1178                 add_input_file(stdin);
1179                 process_files();
1180         } else {
1181                 int i;
1182                 FILE *file;
1183
1184                 for (i = optind; i < argc; i++) {
1185                         if(!strcmp(argv[i], "-") && !in_place) {
1186                                 add_input_file(stdin);
1187                                 process_files();
1188                         } else {
1189                                 file = bb_wfopen(argv[i], "r");
1190                                 if (file) {
1191                                         if(in_place) {
1192                                                 struct stat statbuf;
1193                                                 int nonstdoutfd;
1194
1195                                                 outname=bb_xstrndup(argv[i],strlen(argv[i])+6);
1196                                                 strcat(outname,"XXXXXX");
1197                                                 if(-1==(nonstdoutfd=mkstemp(outname)))
1198                                                         bb_error_msg_and_die("no temp file");
1199                                                 nonstdout=fdopen(nonstdoutfd,"w");
1200                                                 /* Set permissions of output file */
1201                                                 fstat(fileno(file),&statbuf);
1202                                                 fchmod(nonstdoutfd,statbuf.st_mode);
1203                                                 add_input_file(file);
1204                                                 process_files();
1205                                                 fclose(nonstdout);
1206                                                 nonstdout=stdout;
1207                                                 unlink(argv[i]);
1208                                                 rename(outname,argv[i]);
1209                                                 free(outname);
1210                                                 outname=0;
1211                                         } else add_input_file(file);
1212                                 } else {
1213                                         status = EXIT_FAILURE;
1214                                 }
1215                         }
1216                 }
1217                 if(input_file_count>current_input_file) process_files();
1218         }
1219
1220         return status;
1221 }