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  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  19  * General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  24  *
  25  */
  26
  27 /* Code overview.
  28
  29   Files are laid out to avoid unnecessary function declarations.  So for
  30   example, every function add_cmd calls occurs before add_cmd in this file.
  31
  32   add_cmd() is called on each line of sed command text (from a file or from
  33   the command line).  It calls get_address() and parse_cmd_args().  The
  34   resulting sed_cmd_t structures are appended to a linked list
  35   (sed_cmd_head/sed_cmd_tail).
  36
  37   add_input_file() adds a FILE * to the list of input files.  We need to
  38   know them all ahead of time to find the last line for the $ match.
  39
  40   process_files() does actual sedding, reading data lines from each input FILE *
  41   (which could be stdin) and applying the sed command list (sed_cmd_head) to
  42   each of the resulting lines.
  43
  44   sed_main() is where external code calls into this, with a command line.
  45 */
  46
  47
  48 /*
  49         Supported features and commands in this version of sed:
  50
  51          - comments ('#')
  52          - address matching: num|/matchstr/[,num|/matchstr/|$]command
  53          - commands: (p)rint, (d)elete, (s)ubstitue (with g & I flags)
  54          - edit commands: (a)ppend, (i)nsert, (c)hange
  55          - file commands: (r)ead
  56          - backreferences in substitution expressions (\1, \2...\9)
  57          - grouped commands: {cmd1;cmd2}
  58          - transliteration (y/source-chars/dest-chars/)
  59          - pattern space hold space storing / swapping (g, h, x)
  60          - labels / branching (: label, b, t, T)
  61
  62          (Note: Specifying an address (range) to match is *optional*; commands
  63          default to the whole pattern space if no specific address match was
  64          requested.)
  65
  66         Unsupported features:
  67
  68          - most GNU extensions
  69          - and more.
  70
  71         Todo:
  72
  73          - Create a wrapper around regex to make libc's regex conform with sed
  74          - Fix bugs
  75
  76
  77         Reference http://www.opengroup.org/onlinepubs/007904975/utilities/sed.html
  78 */
  79
  80 #include <stdio.h>
  81 #include <unistd.h>             /* for getopt() */
  82 #include <string.h>             /* for strdup() */
  83 #include <errno.h>
  84 #include <ctype.h>              /* for isspace() */
  85 #include <stdlib.h>
  86 #include "busybox.h"
  87 #include "xregex.h"
  88
  89 typedef struct sed_cmd_s {
  90     /* Ordered by alignment requirements: currently 36 bytes on x86 */
  91
  92     /* address storage */
  93     regex_t *beg_match; /* sed -e '/match/cmd' */
  94     regex_t *end_match; /* sed -e '/match/,/end_match/cmd' */
  95     regex_t *sub_match; /* For 's/sub_match/string/' */
  96     int beg_line;               /* 'sed 1p'   0 == apply commands to all lines */
  97     int end_line;               /* 'sed 1,3p' 0 == one line only. -1 = last line ($) */
  98
  99     FILE *file;                 /* File (sr) command writes to, -1 for none. */
 100     char *string;               /* Data string for (saicytb) commands. */
 101
 102     unsigned short which_match;         /* (s) Which match to replace (0 for all) */
 103
 104     /* Bitfields (gcc won't group them if we don't) */
 105     unsigned int invert:1;                      /* the '!' after the address */
 106     unsigned int in_match:1;            /* Next line also included in match? */
 107     unsigned int no_newline:1;          /* Last line written by (sr) had no '\n' */
 108     unsigned int sub_p:1;                       /* (s) print option */
 109
 110
 111     /* GENERAL FIELDS */
 112     char cmd;                           /* The command char: abcdDgGhHilnNpPqrstwxy:={} */
 113     struct sed_cmd_s *next;     /* Next command (linked list, NULL terminated) */
 114 } sed_cmd_t;
 115
 116 /* globals */
 117 /* options */
 118 static int be_quiet, in_place, regex_type;
 119 static FILE *nonstdout;
 120 static char *outname,*hold_space;
 121
 122 /* List of input files */
 123 static int input_file_count,current_input_file;
 124 static FILE **input_file_list;
 125
 126 static const char bad_format_in_subst[] =
 127         "bad format in substitution expression";
 128 static const char *const semicolon_whitespace = "; \n\r\t\v";
 129
 130 static regmatch_t regmatch[10];
 131 static regex_t *previous_regex_ptr;
 132
 133 /* linked list of sed commands */
 134 static sed_cmd_t sed_cmd_head;
 135 static sed_cmd_t *sed_cmd_tail = &sed_cmd_head;
 136
 137 /* Linked list of append lines */
 138 struct append_list {
 139         char *string;
 140         struct append_list *next;
 141 };
 142 static struct append_list *append_head=NULL, *append_tail=NULL;
 143
 144 #ifdef CONFIG_FEATURE_CLEAN_UP
 145 static void free_and_close_stuff(void)
 146 {
 147         sed_cmd_t *sed_cmd = sed_cmd_head.next;
 148
 149         while(append_head) {
 150                 append_tail=append_head->next;
 151                 free(append_head->string);
 152                 free(append_head);
 153                 append_head=append_tail;
 154         }
 155
 156         while (sed_cmd) {
 157                 sed_cmd_t *sed_cmd_next = sed_cmd->next;
 158
 159                 if(sed_cmd->file)
 160                         bb_xprint_and_close_file(sed_cmd->file);
 161
 162                 if (sed_cmd->beg_match) {
 163                         regfree(sed_cmd->beg_match);
 164                         free(sed_cmd->beg_match);
 165                 }
 166                 if (sed_cmd->end_match) {
 167                         regfree(sed_cmd->end_match);
 168                         free(sed_cmd->end_match);
 169                 }
 170                 if (sed_cmd->sub_match) {
 171                         regfree(sed_cmd->sub_match);
 172                         free(sed_cmd->sub_match);
 173                 }
 174                 free(sed_cmd->string);
 175                 free(sed_cmd);
 176                 sed_cmd = sed_cmd_next;
 177         }
 178
 179         if(hold_space) free(hold_space);
 180
 181     while(current_input_file<input_file_count)
 182                 fclose(input_file_list[current_input_file++]);
 183 }
 184 #endif
 185
 186 /* If something bad happens during -i operation, delete temp file */
 187
 188 static void cleanup_outname(void)
 189 {
 190   if(outname) unlink(outname);
 191 }
 192
 193 /* strdup, replacing "\n" with '\n', and "\delimiter" with 'delimiter' */
 194
 195 static void parse_escapes(char *dest, const char *string, int len, char from, char to)
 196 {
 197         int i=0;
 198
 199         while(i<len) {
 200                 if(string[i] == '\\') {
 201                         if(!to || string[i+1] == from) {
 202                                 *(dest++) = to ? to : string[i+1];
 203                                 i+=2;
 204                                 continue;
 205                         } else *(dest++)=string[i++];
 206                 }
 207                 *(dest++) = string[i++];
 208         }
 209         *dest=0;
 210 }
 211
 212 static char *copy_parsing_slashn(const char *string, int len)
 213 {
 214         char *dest=xmalloc(len+1);
 215
 216         parse_escapes(dest,string,len,'n','\n');
 217         return dest;
 218 }
 219
 220
 221 /*
 222  * index_of_next_unescaped_regexp_delim - walks left to right through a string
 223  * beginning at a specified index and returns the index of the next regular
 224  * expression delimiter (typically a forward * slash ('/')) not preceded by
 225  * a backslash ('\').
 226  */
 227 static int index_of_next_unescaped_regexp_delim(const char delimiter,
 228         const char *str)
 229 {
 230         int bracket = -1;
 231         int escaped = 0;
 232         int idx = 0;
 233         char ch;
 234
 235         for (; (ch = str[idx]); idx++) {
 236                 if (bracket != -1) {
 237                         if (ch == ']' && !(bracket == idx - 1 || (bracket == idx - 2
 238                                         && str[idx - 1] == '^')))
 239                                 bracket = -1;
 240                 } else if (escaped)
 241                         escaped = 0;
 242                 else if (ch == '\\')
 243                         escaped = 1;
 244                 else if (ch == '[')
 245                         bracket = idx;
 246                 else if (ch == delimiter)
 247                         return idx;
 248         }
 249
 250         /* if we make it to here, we've hit the end of the string */
 251         return -1;
 252 }
 253
 254 /*
 255  *  Returns the index of the third delimiter
 256  */
 257 static int parse_regex_delim(const char *cmdstr, char **match, char **replace)
 258 {
 259         const char *cmdstr_ptr = cmdstr;
 260         char delimiter;
 261         int idx = 0;
 262
 263         /* verify that the 's' or 'y' is followed by something.  That something
 264          * (typically a 'slash') is now our regexp delimiter... */
 265         if (*cmdstr == '\0') bb_error_msg_and_die(bad_format_in_subst);
 266         delimiter = *(cmdstr_ptr++);
 267
 268         /* save the match string */
 269         idx = index_of_next_unescaped_regexp_delim(delimiter, cmdstr_ptr);
 270         if (idx == -1) {
 271                 bb_error_msg_and_die(bad_format_in_subst);
 272         }
 273         *match = copy_parsing_slashn(cmdstr_ptr, idx);
 274
 275         /* save the replacement string */
 276         cmdstr_ptr += idx + 1;
 277         idx = index_of_next_unescaped_regexp_delim(delimiter, cmdstr_ptr);
 278         if (idx == -1) {
 279                 bb_error_msg_and_die(bad_format_in_subst);
 280         }
 281         *replace = copy_parsing_slashn(cmdstr_ptr, idx);
 282
 283         return ((cmdstr_ptr - cmdstr) + idx);
 284 }
 285
 286 /*
 287  * returns the index in the string just past where the address ends.
 288  */
 289 static int get_address(char *my_str, int *linenum, regex_t ** regex)
 290 {
 291         char *pos = my_str;
 292
 293         if (isdigit(*my_str)) {
 294                 *linenum = strtol(my_str, &pos, 10);
 295                 /* endstr shouldnt ever equal NULL */
 296         } else if (*my_str == '$') {
 297                 *linenum = -1;
 298                 pos++;
 299         } else if (*my_str == '/' || *my_str == '\\') {
 300                 int next;
 301                 char delimiter;
 302                 char *temp;
 303
 304                 if (*my_str == '\\') delimiter = *(++pos);
 305                 else delimiter = '/';
 306                 next = index_of_next_unescaped_regexp_delim(delimiter, ++pos);
 307                 if (next == -1)
 308                         bb_error_msg_and_die("unterminated match expression");
 309
 310                 temp=copy_parsing_slashn(pos,next);
 311                 *regex = (regex_t *) xmalloc(sizeof(regex_t));
 312                 xregcomp(*regex, temp, regex_type|REG_NEWLINE);
 313                 free(temp);
 314                 /* Move position to next character after last delimiter */
 315                 pos+=(next+1);
 316         }
 317         return pos - my_str;
 318 }
 319
 320 /* Grab a filename.  Whitespace at start is skipped, then goes to EOL. */
 321 static int parse_file_cmd(sed_cmd_t * sed_cmd, const char *filecmdstr, char **retval)
 322 {
 323         int start = 0, idx, hack=0;
 324
 325         /* Skip whitespace, then grab filename to end of line */
 326         while (isspace(filecmdstr[start])) start++;
 327         idx=start;
 328         while(filecmdstr[idx] && filecmdstr[idx]!='\n') idx++;
 329         /* If lines glued together, put backslash back. */
 330         if(filecmdstr[idx]=='\n') hack=1;
 331         if(idx==start) bb_error_msg_and_die("Empty filename");
 332         *retval = bb_xstrndup(filecmdstr+start, idx-start+hack+1);
 333         if(hack) *(idx+*retval)='\\';
 334
 335         return idx;
 336 }
 337
 338 static int parse_subst_cmd(sed_cmd_t * const sed_cmd, char *substr)
 339 {
 340         int cflags = regex_type;
 341         char *match;
 342         int idx = 0;
 343
 344         /*
 345          * A substitution command should look something like this:
 346          *    s/match/replace/ #gIpw
 347          *    ||     |        |||
 348          *    mandatory       optional
 349          */
 350         idx = parse_regex_delim(substr, &match, &sed_cmd->string);
 351
 352         /* determine the number of back references in the match string */
 353         /* Note: we compute this here rather than in the do_subst_command()
 354          * function to save processor time, at the expense of a little more memory
 355          * (4 bits) per sed_cmd */
 356
 357         /* process the flags */
 358
 359         sed_cmd->which_match=1;
 360         while (substr[++idx]) {
 361                 /* Parse match number */
 362                 if(isdigit(substr[idx])) {
 363                         if(match[0]!='^') {
 364                                 /* Match 0 treated as all, multiple matches we take the last one. */
 365                                 char *pos=substr+idx;
 366                                 sed_cmd->which_match=(unsigned short)strtol(substr+idx,&pos,10);
 367                                 idx=pos-substr;
 368                         }
 369                         continue;
 370                 }
 371                 /* Skip spaces */
 372                 if(isspace(substr[idx])) continue;
 373
 374                 switch (substr[idx]) {
 375                         /* Replace all occurrences */
 376                         case 'g':
 377                                 if (match[0] != '^') sed_cmd->which_match = 0;
 378                                 break;
 379                         /* Print pattern space */
 380                         case 'p':
 381                                 sed_cmd->sub_p = 1;
 382                                 break;
 383                         case 'w':
 384                         {
 385                                 char *temp;
 386                                 idx+=parse_file_cmd(sed_cmd,substr+idx,&temp);
 387
 388                                 break;
 389                         }
 390                         /* Ignore case (gnu exension) */
 391                         case 'I':
 392                                 cflags |= REG_ICASE;
 393                                 break;
 394                         case ';':
 395                         case '}':
 396                                 goto out;
 397                         default:
 398                                 bb_error_msg_and_die("bad option in substitution expression");
 399                 }
 400         }
 401 out:
 402         /* compile the match string into a regex */
 403         if (*match != '\0') {
 404                 /* If match is empty, we use last regex used at runtime */
 405                 sed_cmd->sub_match = (regex_t *) xmalloc(sizeof(regex_t));
 406                 xregcomp(sed_cmd->sub_match, match, cflags);
 407         }
 408         free(match);
 409
 410         return idx;
 411 }
 412
 413 /*
 414  *  Process the commands arguments
 415  */
 416 static char *parse_cmd_args(sed_cmd_t *sed_cmd, char *cmdstr)
 417 {
 418         /* handle (s)ubstitution command */
 419         if (sed_cmd->cmd == 's') cmdstr += parse_subst_cmd(sed_cmd, cmdstr);
 420         /* handle edit cmds: (a)ppend, (i)nsert, and (c)hange */
 421         else if (strchr("aic", sed_cmd->cmd)) {
 422                 if ((sed_cmd->end_line || sed_cmd->end_match) && sed_cmd->cmd != 'c')
 423                         bb_error_msg_and_die
 424                                 ("only a beginning address can be specified for edit commands");
 425                 for(;;) {
 426                         if(*cmdstr=='\n' || *cmdstr=='\\') {
 427                                 cmdstr++;
 428                                 break;
 429                         } else if(isspace(*cmdstr)) cmdstr++;
 430                         else break;
 431                 }
 432                 sed_cmd->string = bb_xstrdup(cmdstr);
 433                 parse_escapes(sed_cmd->string,sed_cmd->string,strlen(cmdstr),0,0);
 434                 cmdstr += strlen(cmdstr);
 435         /* handle file cmds: (r)ead */
 436         } else if(strchr("rw", sed_cmd->cmd)) {
 437                 if (sed_cmd->end_line || sed_cmd->end_match)
 438                         bb_error_msg_and_die("Command only uses one address");
 439                 cmdstr += parse_file_cmd(sed_cmd, cmdstr, &sed_cmd->string);
 440                 if(sed_cmd->cmd=='w')
 441                         sed_cmd->file=bb_xfopen(sed_cmd->string,"w");
 442         /* handle branch commands */
 443         } else if (strchr(":btT", sed_cmd->cmd)) {
 444                 int length;
 445
 446                 while(isspace(*cmdstr)) cmdstr++;
 447                 length = strcspn(cmdstr, semicolon_whitespace);
 448                 if (length) {
 449                         sed_cmd->string = strndup(cmdstr, length);
 450                         cmdstr += length;
 451                 }
 452         }
 453         /* translation command */
 454         else if (sed_cmd->cmd == 'y') {
 455                 char *match, *replace;
 456                 int i=cmdstr[0];
 457
 458                 cmdstr+=parse_regex_delim(cmdstr, &match, &replace)+1;
 459                 /* \n already parsed, but \delimiter needs unescaping. */
 460                 parse_escapes(match,match,strlen(match),i,i);
 461                 parse_escapes(replace,replace,strlen(replace),i,i);
 462
 463                 sed_cmd->string = xcalloc(1, (strlen(match) + 1) * 2);
 464                 for (i = 0; match[i] && replace[i]; i++) {
 465                         sed_cmd->string[i * 2] = match[i];
 466                         sed_cmd->string[(i * 2) + 1] = replace[i];
 467                 }
 468                 free(match);
 469                 free(replace);
 470         }
 471         /* if it wasnt a single-letter command that takes no arguments
 472          * then it must be an invalid command.
 473          */
 474         else if (strchr("dDgGhHlnNpPqx={}", sed_cmd->cmd) == 0) {
 475                 bb_error_msg_and_die("Unsupported command %c", sed_cmd->cmd);
 476         }
 477
 478         /* give back whatever's left over */
 479         return (cmdstr);
 480 }
 481
 482
 483 /* Parse address+command sets, skipping comment lines. */
 484
 485 static void add_cmd(char *cmdstr)
 486 {
 487         static char *add_cmd_line=NULL;
 488         sed_cmd_t *sed_cmd;
 489         int temp;
 490
 491         /* Append this line to any unfinished line from last time. */
 492         if(add_cmd_line) {
 493                 int lastlen=strlen(add_cmd_line);
 494                 char *tmp=xmalloc(lastlen+strlen(cmdstr)+2);
 495
 496                 memcpy(tmp,add_cmd_line,lastlen);
 497                 tmp[lastlen]='\n';
 498                 strcpy(tmp+lastlen+1,cmdstr);
 499                 free(add_cmd_line);
 500                 cmdstr=add_cmd_line=tmp;
 501         } else add_cmd_line=NULL;
 502
 503         /* If this line ends with backslash, request next line. */
 504         temp=strlen(cmdstr);
 505         if(temp && cmdstr[temp-1]=='\\') {
 506                 if(!add_cmd_line) add_cmd_line=strdup(cmdstr);
 507                 add_cmd_line[temp-1]=0;
 508                 return;
 509         }
 510
 511         /* Loop parsing all commands in this line. */
 512         while(*cmdstr) {
 513                 /* Skip leading whitespace and semicolons */
 514                 cmdstr += strspn(cmdstr, semicolon_whitespace);
 515
 516                 /* If no more commands, exit. */
 517                 if(!*cmdstr) break;
 518
 519                 /* if this is a comment, jump past it and keep going */
 520                 if (*cmdstr == '#') {
 521                         /* "#n" is the same as using -n on the command line */
 522                         if (cmdstr[1] == 'n') be_quiet++;
 523                         if(!(cmdstr=strpbrk(cmdstr, "\n\r"))) break;
 524                         continue;
 525                 }
 526
 527                 /* parse the command
 528                  * format is: [addr][,addr][!]cmd
 529                  *            |----||-----||-|
 530                  *            part1 part2  part3
 531                  */
 532
 533                 sed_cmd = xcalloc(1, sizeof(sed_cmd_t));
 534
 535                 /* first part (if present) is an address: either a '$', a number or a /regex/ */
 536                 cmdstr += get_address(cmdstr, &sed_cmd->beg_line, &sed_cmd->beg_match);
 537
 538                 /* second part (if present) will begin with a comma */
 539                 if (*cmdstr == ',') {
 540                         int idx;
 541
 542                         cmdstr++;
 543                         idx = get_address(cmdstr, &sed_cmd->end_line, &sed_cmd->end_match);
 544                         if (!idx) bb_error_msg_and_die("get_address: no address found in string\n");
 545                         cmdstr += idx;
 546                 }
 547
 548                 /* skip whitespace before the command */
 549                 while (isspace(*cmdstr)) cmdstr++;
 550
 551                 /* Check for inversion flag */
 552                 if (*cmdstr == '!') {
 553                         sed_cmd->invert = 1;
 554                         cmdstr++;
 555
 556                         /* skip whitespace before the command */
 557                         while (isspace(*cmdstr)) cmdstr++;
 558                 }
 559
 560                 /* last part (mandatory) will be a command */
 561                 if (!*cmdstr) bb_error_msg_and_die("missing command");
 562                 sed_cmd->cmd = *(cmdstr++);
 563                 cmdstr = parse_cmd_args(sed_cmd, cmdstr);
 564
 565                 /* Add the command to the command array */
 566                 sed_cmd_tail->next = sed_cmd;
 567                 sed_cmd_tail = sed_cmd_tail->next;
 568         }
 569
 570         /* If we glued multiple lines together, free the memory. */
 571         if(add_cmd_line) {
 572                 free(add_cmd_line);
 573                 add_cmd_line=NULL;
 574         }
 575 }
 576
 577 /* Append to a string, reallocating memory as necessary. */
 578
 579 static struct pipeline {
 580         char *buf;      /* Space to hold string */
 581         int idx;        /* Space used */
 582         int len;        /* Space allocated */
 583 } pipeline;
 584
 585 #define PIPE_GROW 64
 586
 587 static void pipe_putc(char c)
 588 {
 589         if(pipeline.idx==pipeline.len) {
 590                 pipeline.buf = xrealloc(pipeline.buf, pipeline.len + PIPE_GROW);
 591                 pipeline.len+=PIPE_GROW;
 592         }
 593         pipeline.buf[pipeline.idx++] = (c);
 594 }
 595
 596 static void do_subst_w_backrefs(const char *line, const char *replace)
 597 {
 598         int i,j;
 599
 600         /* go through the replacement string */
 601         for (i = 0; replace[i]; i++) {
 602                 /* if we find a backreference (\1, \2, etc.) print the backref'ed * text */
 603                 if (replace[i] == '\\' && replace[i+1]>'0' && replace[i+1]<='9') {
 604                         int backref=replace[++i]-'0';
 605
 606                         /* print out the text held in regmatch[backref] */
 607                         if(regmatch[backref].rm_so != -1)
 608                                 for (j = regmatch[backref].rm_so; j < regmatch[backref].rm_eo; j++)
 609                                         pipe_putc(line[j]);
 610                 }
 611
 612                 /* if we find a backslash escaped character, print the character */
 613                 else if (replace[i] == '\\') pipe_putc(replace[++i]);
 614
 615                 /* if we find an unescaped '&' print out the whole matched text. */
 616                 else if (replace[i] == '&')
 617                         for (j = regmatch[0].rm_so; j < regmatch[0].rm_eo; j++)
 618                                 pipe_putc(line[j]);
 619                 /* Otherwise just output the character. */
 620                 else pipe_putc(replace[i]);
 621         }
 622 }
 623
 624 static int do_subst_command(sed_cmd_t * sed_cmd, char **line)
 625 {
 626         char *oldline = *line;
 627         int altered = 0;
 628         int match_count=0;
 629         regex_t *current_regex;
 630
 631         /* Handle empty regex. */
 632         if (sed_cmd->sub_match == NULL) {
 633                 current_regex = previous_regex_ptr;
 634                 if(!current_regex)
 635                         bb_error_msg_and_die("No previous regexp.");
 636         } else previous_regex_ptr = current_regex = sed_cmd->sub_match;
 637
 638         /* Find the first match */
 639         if(REG_NOMATCH==regexec(current_regex, oldline, 10, regmatch, 0))
 640                 return 0;
 641
 642         /* Initialize temporary output buffer. */
 643         pipeline.buf=xmalloc(PIPE_GROW);
 644         pipeline.len=PIPE_GROW;
 645         pipeline.idx=0;
 646
 647         /* Now loop through, substituting for matches */
 648         do {
 649                 int i;
 650
 651                 /* Work around bug in glibc regexec, demonstrated by:
 652                    echo " a.b" | busybox sed 's [^ .]* x g'
 653                    The match_count check is so not to break
 654                    echo "hi" | busybox sed 's/^/!/g' */
 655                 if(!regmatch[0].rm_so && !regmatch[0].rm_eo && match_count) {
 656                         pipe_putc(*(oldline++));
 657                         continue;
 658                 }
 659
 660                 match_count++;
 661
 662                 /* If we aren't interested in this match, output old line to
 663                    end of match and continue */
 664                 if(sed_cmd->which_match && sed_cmd->which_match!=match_count) {
 665                         for(i=0;i<regmatch[0].rm_eo;i++)
 666                                 pipe_putc(oldline[i]);
 667                         continue;
 668                 }
 669
 670                 /* print everything before the match */
 671                 for (i = 0; i < regmatch[0].rm_so; i++) pipe_putc(oldline[i]);
 672
 673                 /* then print the substitution string */
 674                 do_subst_w_backrefs(oldline, sed_cmd->string);
 675
 676                 /* advance past the match */
 677                 oldline += regmatch[0].rm_eo;
 678                 /* flag that something has changed */
 679                 altered++;
 680
 681                 /* if we're not doing this globally, get out now */
 682                 if (sed_cmd->which_match) break;
 683         } while (*oldline && (regexec(current_regex, oldline, 10, regmatch, 0) != REG_NOMATCH));
 684
 685         /* Copy rest of string into output pipeline */
 686
 687         while(*oldline) pipe_putc(*(oldline++));
 688         pipe_putc(0);
 689
 690         free(*line);
 691         *line = pipeline.buf;
 692         return altered;
 693 }
 694
 695 /* Set command pointer to point to this label.  (Does not handle null label.) */
 696 static sed_cmd_t *branch_to(const char *label)
 697 {
 698         sed_cmd_t *sed_cmd;
 699
 700         for (sed_cmd = sed_cmd_head.next; sed_cmd; sed_cmd = sed_cmd->next) {
 701                 if ((sed_cmd->cmd == ':') && (sed_cmd->string) && (strcmp(sed_cmd->string, label) == 0)) {
 702                         return (sed_cmd);
 703                 }
 704         }
 705         bb_error_msg_and_die("Can't find label for jump to `%s'", label);
 706 }
 707
 708 /* Append copy of string to append buffer */
 709 static void append(char *s)
 710 {
 711         struct append_list *temp=calloc(1,sizeof(struct append_list));
 712
 713         if(append_head)
 714                 append_tail=(append_tail->next=temp);
 715         else append_head=append_tail=temp;
 716         temp->string=strdup(s);
 717 }
 718
 719 static void flush_append(void)
 720 {
 721         /* Output appended lines. */
 722         while(append_head) {
 723                 fprintf(nonstdout,"%s\n",append_head->string);
 724                 append_tail=append_head->next;
 725                 free(append_head->string);
 726                 free(append_head);
 727                 append_head=append_tail;
 728         }
 729         append_head=append_tail=NULL;
 730 }
 731
 732 static void add_input_file(FILE *file)
 733 {
 734         input_file_list=xrealloc(input_file_list,(input_file_count+1)*sizeof(FILE *));
 735         input_file_list[input_file_count++]=file;
 736 }
 737
 738 /* Get next line of input from input_file_list, flushing append buffer and
 739  * noting if we ran out of files without a newline on the last line we read.
 740  */
 741 static char *get_next_line(int *no_newline)
 742 {
 743         char *temp=NULL;
 744         int len;
 745
 746         flush_append();
 747         while(current_input_file<input_file_count) {
 748                 temp=bb_get_line_from_file(input_file_list[current_input_file]);
 749                 if(temp) {
 750                         len=strlen(temp);
 751                         *no_newline=!(len && temp[len-1]=='\n');
 752                         if(!*no_newline) temp[len-1]=0;
 753                         break;
 754                 } else fclose(input_file_list[current_input_file++]);
 755         }
 756
 757         return temp;
 758 }
 759
 760 /* Output line of text.  missing_newline means the last line output did not
 761    end with a newline.  no_newline means this line does not end with a
 762    newline. */
 763
 764 static int puts_maybe_newline(char *s, FILE *file, int missing_newline, int no_newline)
 765 {
 766         if(missing_newline) fputc('\n',file);
 767         fputs(s,file);
 768         if(!no_newline) fputc('\n',file);
 769
 770     if(ferror(file)) {
 771                 fprintf(stderr,"Write failed.\n");
 772                 exit(4);  /* It's what gnu sed exits with... */
 773         }
 774
 775         return no_newline;
 776 }
 777
 778 #define sed_puts(s,n) missing_newline=puts_maybe_newline(s,nonstdout,missing_newline,n)
 779
 780 static void process_files(void)
 781 {
 782         char *pattern_space, *next_line;
 783         int linenum = 0, missing_newline=0;
 784         int no_newline,next_no_newline=0;
 785
 786         next_line = get_next_line(&next_no_newline);
 787
 788         /* go through every line in each file */
 789         for(;;) {
 790                 sed_cmd_t *sed_cmd;
 791                 int substituted=0;
 792
 793                 /* Advance to next line.  Stop if out of lines. */
 794                 if(!(pattern_space=next_line)) break;
 795                 no_newline=next_no_newline;
 796
 797                 /* Read one line in advance so we can act on the last line, the '$' address */
 798                 next_line = get_next_line(&next_no_newline);
 799                 linenum++;
 800 restart:
 801                 /* for every line, go through all the commands */
 802                 for (sed_cmd = sed_cmd_head.next; sed_cmd; sed_cmd = sed_cmd->next) {
 803                         int old_matched, matched;
 804
 805                         old_matched = sed_cmd->in_match;
 806
 807                         /* Determine if this command matches this line: */
 808
 809                         /* Are we continuing a previous multi-line match? */
 810
 811                         sed_cmd->in_match = sed_cmd->in_match
 812
 813                         /* Or is no range necessary? */
 814                                 || (!sed_cmd->beg_line && !sed_cmd->end_line
 815                                         && !sed_cmd->beg_match && !sed_cmd->end_match)
 816
 817                         /* Or did we match the start of a numerical range? */
 818                                 || (sed_cmd->beg_line > 0 && (sed_cmd->beg_line == linenum))
 819
 820                         /* Or does this line match our begin address regex? */
 821                                 || (sed_cmd->beg_match &&
 822                                     !regexec(sed_cmd->beg_match, pattern_space, 0, NULL, 0))
 823
 824                         /* Or did we match last line of input? */
 825                                 || (sed_cmd->beg_line == -1 && next_line == NULL);
 826
 827                         /* Snapshot the value */
 828
 829                         matched = sed_cmd->in_match;
 830
 831                         /* Is this line the end of the current match? */
 832
 833                         if(matched) {
 834                                 sed_cmd->in_match = !(
 835                                         /* has the ending line come, or is this a single address command? */
 836                                         (sed_cmd->end_line ?
 837                                                 sed_cmd->end_line==-1 ?
 838                                                         !next_line
 839                                                         : sed_cmd->end_line<=linenum
 840                                                 : !sed_cmd->end_match)
 841                                         /* or does this line matches our last address regex */
 842                                         || (sed_cmd->end_match && old_matched && (regexec(sed_cmd->end_match, pattern_space, 0, NULL, 0) == 0))
 843                                 );
 844                         }
 845
 846                         /* Skip blocks of commands we didn't match. */
 847                         if (sed_cmd->cmd == '{') {
 848                                 if(sed_cmd->invert ? matched : !matched)
 849                                         while(sed_cmd && sed_cmd->cmd!='}') sed_cmd=sed_cmd->next;
 850                                 if(!sed_cmd) bb_error_msg_and_die("Unterminated {");
 851                                 continue;
 852                         }
 853
 854                         /* Okay, so did this line match? */
 855                         if (sed_cmd->invert ? !matched : matched) {
 856                                 /* Update last used regex in case a blank substitute BRE is found */
 857                                 if (sed_cmd->beg_match) {
 858                                         previous_regex_ptr = sed_cmd->beg_match;
 859                                 }
 860
 861                                 /* actual sedding */
 862                                 switch (sed_cmd->cmd) {
 863
 864                                         /* Print line number */
 865                                         case '=':
 866                                                 fprintf(nonstdout,"%d\n", linenum);
 867                                                 break;
 868
 869                                         /* Write the current pattern space up to the first newline */
 870                                         case 'P':
 871                                         {
 872                                                 char *tmp = strchr(pattern_space, '\n');
 873
 874                                                 if (tmp) {
 875                                                         *tmp = '\0';
 876                                                         sed_puts(pattern_space,1);
 877                                                         *tmp = '\n';
 878                                                         break;
 879                                                 }
 880                                                 /* Fall Through */
 881                                         }
 882
 883                                         /* Write the current pattern space to output */
 884                                         case 'p':
 885                                                 sed_puts(pattern_space,no_newline);
 886                                                 break;
 887                                         /* Delete up through first newline */
 888                                         case 'D':
 889                                         {
 890                                                 char *tmp = strchr(pattern_space,'\n');
 891
 892                                                 if(tmp) {
 893                                                         tmp=bb_xstrdup(tmp+1);
 894                                                         free(pattern_space);
 895                                                         pattern_space=tmp;
 896                                                         goto restart;
 897                                                 }
 898                                         }
 899                                         /* discard this line. */
 900                                         case 'd':
 901                                                 goto discard_line;
 902
 903                                         /* Substitute with regex */
 904                                         case 's':
 905                                                 if(do_subst_command(sed_cmd, &pattern_space)) {
 906                                                         substituted|=1;
 907
 908                                                         /* handle p option */
 909                                                         if(sed_cmd->sub_p)
 910                                                                 sed_puts(pattern_space,no_newline);
 911                                                         /* handle w option */
 912                                                         if(sed_cmd->file)
 913                                                                 sed_cmd->no_newline=puts_maybe_newline(pattern_space, sed_cmd->file, sed_cmd->no_newline, no_newline);
 914
 915                                                 }
 916                                                 break;
 917
 918                                         /* Append line to linked list to be printed later */
 919                                         case 'a':
 920                                         {
 921                                                 append(sed_cmd->string);
 922                                                 break;
 923                                         }
 924
 925                                         /* Insert text before this line */
 926                                         case 'i':
 927                                                 sed_puts(sed_cmd->string,1);
 928                                                 break;
 929
 930                                         /* Cut and paste text (replace) */
 931                                         case 'c':
 932                                                 /* Only triggers on last line of a matching range. */
 933                                                 if (!sed_cmd->in_match) sed_puts(sed_cmd->string,0);
 934                                                 goto discard_line;
 935
 936                                         /* Read file, append contents to output */
 937                                         case 'r':
 938                                         {
 939                                                 FILE *outfile;
 940
 941                                                 outfile = fopen(sed_cmd->string, "r");
 942                                                 if (outfile) {
 943                                                         char *line;
 944
 945                                                         while ((line = bb_get_chomped_line_from_file(outfile))
 946                                                                         != NULL)
 947                                                                 append(line);
 948                                                         bb_xprint_and_close_file(outfile);
 949                                                 }
 950
 951                                                 break;
 952                                         }
 953
 954                                         /* Write pattern space to file. */
 955                                         case 'w':
 956                                                 sed_cmd->no_newline=puts_maybe_newline(pattern_space,sed_cmd->file, sed_cmd->no_newline,no_newline);
 957                                                 break;
 958
 959                                         /* Read next line from input */
 960                                         case 'n':
 961                                                 if (!be_quiet)
 962                                                         sed_puts(pattern_space,no_newline);
 963                                                 if (next_line) {
 964                                                         free(pattern_space);
 965                                                         pattern_space = next_line;
 966                                                         no_newline=next_no_newline;
 967                                                         next_line = get_next_line(&next_no_newline);
 968                                                         linenum++;
 969                                                         break;
 970                                                 }
 971                                                 /* fall through */
 972
 973                                         /* Quit.  End of script, end of input. */
 974                                         case 'q':
 975                                                 /* Exit the outer while loop */
 976                                                 free(next_line);
 977                                                 next_line = NULL;
 978                                                 goto discard_commands;
 979
 980                                         /* Append the next line to the current line */
 981                                         case 'N':
 982                                         {
 983                                                 /* If no next line, jump to end of script and exit. */
 984                                                 if (next_line == NULL) {
 985                                                         /* Jump to end of script and exit */
 986                                                         free(next_line);
 987                                                         next_line = NULL;
 988                                                         goto discard_line;
 989                                                 /* append next_line, read new next_line. */
 990                                                 } else {
 991                                                         int len=strlen(pattern_space);
 992
 993                                                         pattern_space = realloc(pattern_space, len + strlen(next_line) + 2);
 994                                                         pattern_space[len]='\n';
 995                                                         strcpy(pattern_space+len+1, next_line);
 996                                                         no_newline=next_no_newline;
 997                                                         next_line = get_next_line(&next_no_newline);
 998                                                         linenum++;
 999                                                 }
1000                                                 break;
1001                                         }
1002
1003                                         /* Test/branch if substitution occurred */
1004                                         case 't':
1005                                                 if(!substituted) break;
1006                                                 substituted=0;
1007                                                 /* Fall through */
1008                                         /* Test/branch if substitution didn't occur */
1009                                         case 'T':
1010                                                 if (substituted) break;
1011                                                 /* Fall through */
1012                                         /* Branch to label */
1013                                         case 'b':
1014                                                 if (!sed_cmd->string) goto discard_commands;
1015                                                 else sed_cmd = branch_to(sed_cmd->string);
1016                                                 break;
1017                                         /* Transliterate characters */
1018                                         case 'y':
1019                                         {
1020                                                 int i;
1021
1022                                                 for (i = 0; pattern_space[i]; i++) {
1023                                                         int j;
1024
1025                                                         for (j = 0; sed_cmd->string[j]; j += 2) {
1026                                                                 if (pattern_space[i] == sed_cmd->string[j]) {
1027                                                                         pattern_space[i] = sed_cmd->string[j + 1];
1028                                                                         break;
1029                                                                 }
1030                                                         }
1031                                                 }
1032
1033                                                 break;
1034                                         }
1035                                         case 'g':       /* Replace pattern space with hold space */
1036                                                 free(pattern_space);
1037                                                 pattern_space = strdup(hold_space ? hold_space : "");
1038                                                 break;
1039                                         case 'G':       /* Append newline and hold space to pattern space */
1040                                         {
1041                                                 int pattern_space_size = 2;
1042                                                 int hold_space_size = 0;
1043
1044                                                 if (pattern_space)
1045                                                         pattern_space_size += strlen(pattern_space);
1046                                                 if (hold_space) hold_space_size = strlen(hold_space);
1047                                                 pattern_space = xrealloc(pattern_space, pattern_space_size + hold_space_size);
1048                                                 if (pattern_space_size == 2) pattern_space[0]=0;
1049                                                 strcat(pattern_space, "\n");
1050                                                 if (hold_space) strcat(pattern_space, hold_space);
1051                                                 no_newline=0;
1052
1053                                                 break;
1054                                         }
1055                                         case 'h':       /* Replace hold space with pattern space */
1056                                                 free(hold_space);
1057                                                 hold_space = strdup(pattern_space);
1058                                                 break;
1059                                         case 'H':       /* Append newline and pattern space to hold space */
1060                                         {
1061                                                 int hold_space_size = 2;
1062                                                 int pattern_space_size = 0;
1063
1064                                                 if (hold_space) hold_space_size += strlen(hold_space);
1065                                                 if (pattern_space)
1066                                                         pattern_space_size = strlen(pattern_space);
1067                                                 hold_space = xrealloc(hold_space,
1068                                                                                         hold_space_size + pattern_space_size);
1069
1070                                                 if (hold_space_size == 2) hold_space[0]=0;
1071                                                 strcat(hold_space, "\n");
1072                                                 if (pattern_space) strcat(hold_space, pattern_space);
1073
1074                                                 break;
1075                                         }
1076                                         case 'x': /* Exchange hold and pattern space */
1077                                         {
1078                                                 char *tmp = pattern_space;
1079                                                 pattern_space = hold_space;
1080                                                 no_newline=0;
1081                                                 hold_space = tmp;
1082                                                 break;
1083                                         }
1084                                 }
1085                         }
1086                 }
1087
1088                 /*
1089                  * exit point from sedding...
1090                  */
1091 discard_commands:
1092                 /* we will print the line unless we were told to be quiet ('-n')
1093                    or if the line was suppressed (ala 'd'elete) */
1094                 if (!be_quiet) sed_puts(pattern_space,no_newline);
1095
1096                 /* Delete and such jump here. */
1097 discard_line:
1098                 flush_append();
1099                 free(pattern_space);
1100         }
1101 }
1102
1103 /* It is possible to have a command line argument with embedded
1104    newlines.  This counts as multiple command lines. */
1105
1106 static void add_cmd_block(char *cmdstr)
1107 {
1108         int go=1;
1109         char *temp=bb_xstrdup(cmdstr),*temp2=temp;
1110
1111         while(go) {
1112                 int len=strcspn(temp2,"\n");
1113                 if(!temp2[len]) go=0;
1114                 else temp2[len]=0;
1115                 add_cmd(temp2);
1116                 temp2+=len+1;
1117         }
1118         free(temp);
1119 }
1120
1121 extern int sed_main(int argc, char **argv)
1122 {
1123         int status = EXIT_SUCCESS, opt, getpat = 1;
1124
1125 #ifdef CONFIG_FEATURE_CLEAN_UP
1126         /* destroy command strings on exit */
1127         if (atexit(free_and_close_stuff) == -1)
1128                 bb_perror_msg_and_die("atexit");
1129 #endif
1130
1131 #define LIE_TO_AUTOCONF
1132 #ifdef LIE_TO_AUTOCONF
1133         if(argc==2 && !strcmp(argv[1],"--version")) {
1134                 printf("This is not GNU sed version 4.0\n");
1135                 exit(0);
1136         }
1137 #endif
1138
1139         /* do normal option parsing */
1140         while ((opt = getopt(argc, argv, "irne:f:")) > 0) {
1141                 switch (opt) {
1142                 case 'i':
1143                         in_place++;
1144                         atexit(cleanup_outname);
1145                         break;
1146                 case 'r':
1147                         regex_type|=REG_EXTENDED;
1148                         break;
1149                 case 'n':
1150                         be_quiet++;
1151                         break;
1152                 case 'e':
1153                         add_cmd_block(optarg);
1154                         getpat=0;
1155                         break;
1156                 case 'f':
1157                 {
1158                         FILE *cmdfile;
1159                         char *line;
1160
1161                         cmdfile = bb_xfopen(optarg, "r");
1162
1163                         while ((line = bb_get_chomped_line_from_file(cmdfile))
1164                                  != NULL) {
1165                                 add_cmd(line);
1166                                 getpat=0;
1167                                 free(line);
1168                         }
1169                         bb_xprint_and_close_file(cmdfile);
1170
1171                         break;
1172                 }
1173                 default:
1174                         bb_show_usage();
1175                 }
1176         }
1177
1178         /* if we didn't get a pattern from -e or -f, use argv[optind] */
1179         if(getpat) {
1180                 if (argv[optind] == NULL)
1181                         bb_show_usage();
1182                 else
1183                         add_cmd_block(argv[optind++]);
1184         }
1185         /* Flush any unfinished commands. */
1186         add_cmd("");
1187
1188         /* By default, we write to stdout */
1189         nonstdout=stdout;
1190
1191         /* argv[(optind)..(argc-1)] should be names of file to process. If no
1192          * files were specified or '-' was specified, take input from stdin.
1193          * Otherwise, we process all the files specified. */
1194         if (argv[optind] == NULL) {
1195                 if(in_place) bb_error_msg_and_die("Filename required for -i");
1196                 add_input_file(stdin);
1197                 process_files();
1198         } else {
1199                 int i;
1200                 FILE *file;
1201
1202                 for (i = optind; i < argc; i++) {
1203                         if(!strcmp(argv[i], "-") && !in_place) {
1204                                 add_input_file(stdin);
1205                                 process_files();
1206                         } else {
1207                                 file = bb_wfopen(argv[i], "r");
1208                                 if (file) {
1209                                         if(in_place) {
1210                                                 struct stat statbuf;
1211                                                 int nonstdoutfd;
1212
1213                                                 outname=bb_xstrndup(argv[i],strlen(argv[i])+6);
1214                                                 strcat(outname,"XXXXXX");
1215                                                 if(-1==(nonstdoutfd=mkstemp(outname)))
1216                                                         bb_error_msg_and_die("no temp file");
1217                                                 nonstdout=fdopen(nonstdoutfd,"w");
1218                                                 /* Set permissions of output file */
1219                                                 fstat(fileno(file),&statbuf);
1220                                                 fchmod(nonstdoutfd,statbuf.st_mode);
1221                                                 add_input_file(file);
1222                                                 process_files();
1223                                                 fclose(nonstdout);
1224                                                 nonstdout=stdout;
1225                                                 unlink(argv[i]);
1226                                                 rename(outname,argv[i]);
1227                                                 free(outname);
1228                                                 outname=0;
1229                                         } else add_input_file(file);
1230                                 } else {
1231                                         status = EXIT_FAILURE;
1232                                 }
1233                         }
1234                 }
1235                 if(input_file_count>current_input_file) process_files();
1236         }
1237
1238         return status;
1239 }