/* $OpenBSD: pat_rep.c,v 1.29 2005/04/21 21:47:18 beck Exp $ */ /* $NetBSD: pat_rep.c,v 1.4 1995/03/21 09:07:33 cgd Exp $ */ /*- * Copyright (c) 1992 Keith Muller. * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Keith Muller of the University of California, San Diego. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint #if 0 static const char sccsid[] = "@(#)pat_rep.c 8.2 (Berkeley) 4/18/94"; #else static const char rcsid[] = "$OpenBSD: pat_rep.c,v 1.29 2005/04/21 21:47:18 beck Exp $"; #endif #endif /* not lint */ #include #include #include #include #include #include #include #include #include #include #include "pax.h" #include "pat_rep.h" #include "extern.h" /* * routines to handle pattern matching, name modification (regular expression * substitution and interactive renames), and destination name modification for * copy (-rw). Both file name and link names are adjusted as required in these * routines. */ #define MAXSUBEXP 10 /* max subexpressions, DO NOT CHANGE */ static PATTERN *pathead = NULL; /* file pattern match list head */ static PATTERN *pattail = NULL; /* file pattern match list tail */ static REPLACE *rephead = NULL; /* replacement string list head */ static REPLACE *reptail = NULL; /* replacement string list tail */ static int rep_name(char *, size_t, int *, int); static int tty_rename(ARCHD *); static int fix_path(char *, int *, char *, int); static int fn_match(char *, char *, char **); static char * range_match(char *, int); static int resub(regex_t *, regmatch_t *, char *, char *, char *, char *); /* * rep_add() * parses the -s replacement string; compiles the regular expression * and stores the compiled value and it's replacement string together in * replacement string list. Input to this function is of the form: * /old/new/pg * The first char in the string specifies the delimiter used by this * replacement string. "Old" is a regular expression in "ed" format which * is compiled by regcomp() and is applied to filenames. "new" is the * substitution string; p and g are options flags for printing and global * replacement (over the single filename) * Return: * 0 if a proper replacement string and regular expression was added to * the list of replacement patterns; -1 otherwise. */ int rep_add(char *str) { char *pt1; char *pt2; REPLACE *rep; int res; char rebuf[BUFSIZ]; /* * throw out the bad parameters */ if ((str == NULL) || (*str == '\0')) { paxwarn(1, "Empty replacement string"); return(-1); } /* * first character in the string specifies what the delimiter is for * this expression */ for (pt1 = str+1; *pt1; pt1++) { if (*pt1 == '\\') { pt1++; continue; } if (*pt1 == *str) break; } if (*pt1 == '\0') { paxwarn(1, "Invalid replacement string %s", str); return(-1); } /* * allocate space for the node that handles this replacement pattern * and split out the regular expression and try to compile it */ if ((rep = (REPLACE *)malloc(sizeof(REPLACE))) == NULL) { paxwarn(1, "Unable to allocate memory for replacement string"); return(-1); } *pt1 = '\0'; if ((res = regcomp(&(rep->rcmp), str+1, 0)) != 0) { regerror(res, &(rep->rcmp), rebuf, sizeof(rebuf)); paxwarn(1, "%s while compiling regular expression %s", rebuf, str); (void)free((char *)rep); return(-1); } /* * put the delimiter back in case we need an error message and * locate the delimiter at the end of the replacement string * we then point the node at the new substitution string */ *pt1++ = *str; for (pt2 = pt1; *pt2; pt2++) { if (*pt2 == '\\') { pt2++; continue; } if (*pt2 == *str) break; } if (*pt2 == '\0') { regfree(&(rep->rcmp)); (void)free((char *)rep); paxwarn(1, "Invalid replacement string %s", str); return(-1); } *pt2 = '\0'; rep->nstr = pt1; pt1 = pt2++; rep->flgs = 0; /* * set the options if any */ while (*pt2 != '\0') { switch (*pt2) { case 'g': case 'G': rep->flgs |= GLOB; break; case 'p': case 'P': rep->flgs |= PRNT; break; default: regfree(&(rep->rcmp)); (void)free((char *)rep); *pt1 = *str; paxwarn(1, "Invalid replacement string option %s", str); return(-1); } ++pt2; } /* * all done, link it in at the end */ rep->fow = NULL; if (rephead == NULL) { reptail = rephead = rep; return(0); } reptail->fow = rep; reptail = rep; return(0); } /* * pat_add() * add a pattern match to the pattern match list. Pattern matches are used * to select which archive members are extracted. (They appear as * arguments to pax in the list and read modes). If no patterns are * supplied to pax, all members in the archive will be selected (and the * pattern match list is empty). * Return: * 0 if the pattern was added to the list, -1 otherwise */ int pat_add(char *str, char *chdname) { PATTERN *pt; /* * throw out the junk */ if ((str == NULL) || (*str == '\0')) { paxwarn(1, "Empty pattern string"); return(-1); } /* * allocate space for the pattern and store the pattern. the pattern is * part of argv so do not bother to copy it, just point at it. Add the * node to the end of the pattern list */ if ((pt = (PATTERN *)malloc(sizeof(PATTERN))) == NULL) { paxwarn(1, "Unable to allocate memory for pattern string"); return(-1); } pt->pstr = str; pt->pend = NULL; pt->plen = strlen(str); pt->fow = NULL; pt->flgs = 0; pt->chdname = chdname; if (pathead == NULL) { pattail = pathead = pt; return(0); } pattail->fow = pt; pattail = pt; return(0); } /* * pat_chk() * complain if any the user supplied pattern did not result in a match to * a selected archive member. */ void pat_chk(void) { PATTERN *pt; int wban = 0; /* * walk down the list checking the flags to make sure MTCH was set, * if not complain */ for (pt = pathead; pt != NULL; pt = pt->fow) { if (pt->flgs & MTCH) continue; if (!wban) { paxwarn(1, "WARNING! These patterns were not matched:"); ++wban; } (void)fprintf(stderr, "%s\n", pt->pstr); } } /* * pat_sel() * the archive member which matches a pattern was selected. Mark the * pattern as having selected an archive member. arcn->pat points at the * pattern that was matched. arcn->pat is set in pat_match() * * NOTE: When the -c option is used, we are called when there was no match * by pat_match() (that means we did match before the inverted sense of * the logic). Now this seems really strange at first, but with -c we * need to keep track of those patterns that cause an archive member to NOT * be selected (it found an archive member with a specified pattern) * Return: * 0 if the pattern pointed at by arcn->pat was tagged as creating a * match, -1 otherwise. */ int pat_sel(ARCHD *arcn) { PATTERN *pt; PATTERN **ppt; int len; /* * if no patterns just return */ if ((pathead == NULL) || ((pt = arcn->pat) == NULL)) return(0); /* * when we are NOT limited to a single match per pattern mark the * pattern and return */ if (!nflag) { pt->flgs |= MTCH; return(0); } /* * we reach this point only when we allow a single selected match per * pattern, if the pattern matches a directory and we do not have -d * (dflag) we are done with this pattern. We may also be handed a file * in the subtree of a directory. in that case when we are operating * with -d, this pattern was already selected and we are done */ if (pt->flgs & DIR_MTCH) return(0); if (!dflag && ((pt->pend != NULL) || (arcn->type == PAX_DIR))) { /* * ok we matched a directory and we are allowing * subtree matches but because of the -n only its children will * match. This is tagged as a DIR_MTCH type. * WATCH IT, the code assumes that pt->pend points * into arcn->name and arcn->name has not been modified. * If not we will have a big mess. Yup this is another kludge */ /* * if this was a prefix match, remove trailing part of path * so we can copy it. Future matches will be exact prefix match */ if (pt->pend != NULL) *pt->pend = '\0'; if ((pt->pstr = strdup(arcn->name)) == NULL) { paxwarn(1, "Pattern select out of memory"); if (pt->pend != NULL) *pt->pend = '/'; pt->pend = NULL; return(-1); } /* * put the trailing / back in the source string */ if (pt->pend != NULL) { *pt->pend = '/'; pt->pend = NULL; } pt->plen = strlen(pt->pstr); /* * strip off any trailing /, this should really never happen */ len = pt->plen - 1; if (*(pt->pstr + len) == '/') { *(pt->pstr + len) = '\0'; pt->plen = len; } pt->flgs = DIR_MTCH | MTCH; arcn->pat = pt; return(0); } /* * we are then done with this pattern, so we delete it from the list * because it can never be used for another match. * Seems kind of strange to do for a -c, but the pax spec is really * vague on the interaction of -c, -n and -d. We assume that when -c * and the pattern rejects a member (i.e. it matched it) it is done. * In effect we place the order of the flags as having -c last. */ pt = pathead; ppt = &pathead; while ((pt != NULL) && (pt != arcn->pat)) { ppt = &(pt->fow); pt = pt->fow; } if (pt == NULL) { /* * should never happen.... */ paxwarn(1, "Pattern list inconsistent"); return(-1); } *ppt = pt->fow; (void)free((char *)pt); arcn->pat = NULL; return(0); } /* * pat_match() * see if this archive member matches any supplied pattern, if a match * is found, arcn->pat is set to point at the potential pattern. Later if * this archive member is "selected" we process and mark the pattern as * one which matched a selected archive member (see pat_sel()) * Return: * 0 if this archive member should be processed, 1 if it should be * skipped and -1 if we are done with all patterns (and pax should quit * looking for more members) */ int pat_match(ARCHD *arcn) { PATTERN *pt; arcn->pat = NULL; /* * if there are no more patterns and we have -n (and not -c) we are * done. otherwise with no patterns to match, matches all */ if (pathead == NULL) { if (nflag && !cflag) return(-1); return(0); } /* * have to search down the list one at a time looking for a match. */ pt = pathead; while (pt != NULL) { /* * check for a file name match unless we have DIR_MTCH set in * this pattern then we want a prefix match */ if (pt->flgs & DIR_MTCH) { /* * this pattern was matched before to a directory * as we must have -n set for this (but not -d). We can * only match CHILDREN of that directory so we must use * an exact prefix match (no wildcards). */ if ((arcn->name[pt->plen] == '/') && (strncmp(pt->pstr, arcn->name, pt->plen) == 0)) break; } else if (fn_match(pt->pstr, arcn->name, &pt->pend) == 0) break; pt = pt->fow; } /* * return the result, remember that cflag (-c) inverts the sense of a * match */ if (pt == NULL) return(cflag ? 0 : 1); /* * we had a match, now when we invert the sense (-c) we reject this * member. However we have to tag the pattern a being successful, (in a * match, not in selecting a archive member) so we call pat_sel() here. */ arcn->pat = pt; if (!cflag) return(0); if (pat_sel(arcn) < 0) return(-1); arcn->pat = NULL; return(1); } /* * fn_match() * Return: * 0 if this archive member should be processed, 1 if it should be * skipped and -1 if we are done with all patterns (and pax should quit * looking for more members) * Note: *pend may be changed to show where the prefix ends. */ static int fn_match(char *pattern, char *string, char **pend) { char c; char test; *pend = NULL; for (;;) { switch (c = *pattern++) { case '\0': /* * Ok we found an exact match */ if (*string == '\0') return(0); /* * Check if it is a prefix match */ if ((dflag == 1) || (*string != '/')) return(-1); /* * It is a prefix match, remember where the trailing * / is located */ *pend = string; return(0); case '?': if ((test = *string++) == '\0') return (-1); break; case '*': c = *pattern; /* * Collapse multiple *'s. */ while (c == '*') c = *++pattern; /* * Optimized hack for pattern with a * at the end */ if (c == '\0') return (0); /* * General case, use recursion. */ while ((test = *string) != '\0') { if (!fn_match(pattern, string, pend)) return (0); ++string; } return (-1); case '[': /* * range match */ if (((test = *string++) == '\0') || ((pattern = range_match(pattern, test)) == NULL)) return (-1); break; case '\\': default: if (c != *string++) return (-1); break; } } /* NOTREACHED */ } static char * range_match(char *pattern, int test) { char c; char c2; int negate; int ok = 0; if ((negate = (*pattern == '!')) != 0) ++pattern; while ((c = *pattern++) != ']') { /* * Illegal pattern */ if (c == '\0') return (NULL); if ((*pattern == '-') && ((c2 = pattern[1]) != '\0') && (c2 != ']')) { if ((c <= test) && (test <= c2)) ok = 1; pattern += 2; } else if (c == test) ok = 1; } return (ok == negate ? NULL : pattern); } /* * mod_name() * modify a selected file name. first attempt to apply replacement string * expressions, then apply interactive file rename. We apply replacement * string expressions to both filenames and file links (if we didn't the * links would point to the wrong place, and we could never be able to * move an archive that has a file link in it). When we rename files * interactively, we store that mapping (old name to user input name) so * if we spot any file links to the old file name in the future, we will * know exactly how to fix the file link. * Return: * 0 continue to process file, 1 skip this file, -1 pax is finished */ int mod_name(ARCHD *arcn) { int res = 0; /* * Strip off leading '/' if appropriate. * Currently, this option is only set for the tar format. */ if (rmleadslash && arcn->name[0] == '/') { if (arcn->name[1] == '\0') { arcn->name[0] = '.'; } else { (void)memmove(arcn->name, &arcn->name[1], strlen(arcn->name)); arcn->nlen--; } if (rmleadslash < 2) { rmleadslash = 2; paxwarn(0, "Removing leading / from absolute path names in the archive"); } } if (rmleadslash && arcn->ln_name[0] == '/' && (arcn->type == PAX_HLK || arcn->type == PAX_HRG)) { if (arcn->ln_name[1] == '\0') { arcn->ln_name[0] = '.'; } else { (void)memmove(arcn->ln_name, &arcn->ln_name[1], strlen(arcn->ln_name)); arcn->ln_nlen--; } if (rmleadslash < 2) { rmleadslash = 2; paxwarn(0, "Removing leading / from absolute path names in the archive"); } } /* * IMPORTANT: We have a problem. what do we do with symlinks? * Modifying a hard link name makes sense, as we know the file it * points at should have been seen already in the archive (and if it * wasn't seen because of a read error or a bad archive, we lose * anyway). But there are no such requirements for symlinks. On one * hand the symlink that refers to a file in the archive will have to * be modified to so it will still work at its new location in the * file system. On the other hand a symlink that points elsewhere (and * should continue to do so) should not be modified. There is clearly * no perfect solution here. So we handle them like hardlinks. Clearly * a replacement made by the interactive rename mapping is very likely * to be correct since it applies to a single file and is an exact * match. The regular expression replacements are a little harder to * justify though. We claim that the symlink name is only likely * to be replaced when it points within the file tree being moved and * in that case it should be modified. what we really need to do is to * call an oracle here. :) */ if (rephead != NULL) { /* * we have replacement strings, modify the name and the link * name if any. */ if ((res = rep_name(arcn->name, sizeof(arcn->name), &(arcn->nlen), 1)) != 0) return(res); if (((arcn->type == PAX_SLK) || (arcn->type == PAX_HLK) || (arcn->type == PAX_HRG)) && ((res = rep_name(arcn->ln_name, sizeof(arcn->ln_name), &(arcn->ln_nlen), 0)) != 0)) return(res); } if (iflag) { /* * perform interactive file rename, then map the link if any */ if ((res = tty_rename(arcn)) != 0) return(res); if ((arcn->type == PAX_SLK) || (arcn->type == PAX_HLK) || (arcn->type == PAX_HRG)) sub_name(arcn->ln_name, &(arcn->ln_nlen), sizeof(arcn->ln_name)); } return(res); } /* * tty_rename() * Prompt the user for a replacement file name. A "." keeps the old name, * a empty line skips the file, and an EOF on reading the tty, will cause * pax to stop processing and exit. Otherwise the file name input, replaces * the old one. * Return: * 0 process this file, 1 skip this file, -1 we need to exit pax */ static int tty_rename(ARCHD *arcn) { char tmpname[PAXPATHLEN+2]; int res; /* * prompt user for the replacement name for a file, keep trying until * we get some reasonable input. Archives may have more than one file * on them with the same name (from updates etc). We print verbose info * on the file so the user knows what is up. */ tty_prnt("\nATTENTION: %s interactive file rename operation.\n", argv0); for (;;) { ls_tty(arcn); tty_prnt("Input new name, or a \".\" to keep the old name, "); tty_prnt("or a \"return\" to skip this file.\n"); tty_prnt("Input > "); if (tty_read(tmpname, sizeof(tmpname)) < 0) return(-1); if (strcmp(tmpname, "..") == 0) { tty_prnt("Try again, illegal file name: ..\n"); continue; } if (strlen(tmpname) > PAXPATHLEN) { tty_prnt("Try again, file name too long\n"); continue; } break; } /* * empty file name, skips this file. a "." leaves it alone */ if (tmpname[0] == '\0') { tty_prnt("Skipping file.\n"); return(1); } if ((tmpname[0] == '.') && (tmpname[1] == '\0')) { tty_prnt("Processing continues, name unchanged.\n"); return(0); } /* * ok the name changed. We may run into links that point at this * file later. we have to remember where the user sent the file * in order to repair any links. */ tty_prnt("Processing continues, name changed to: %s\n", tmpname); res = add_name(arcn->name, arcn->nlen, tmpname); arcn->nlen = strlcpy(arcn->name, tmpname, sizeof(arcn->name)); if (arcn->nlen >= sizeof(arcn->name)) arcn->nlen = sizeof(arcn->name) - 1; /* XXX truncate? */ if (res < 0) return(-1); return(0); } /* * set_dest() * fix up the file name and the link name (if any) so this file will land * in the destination directory (used during copy() -rw). * Return: * 0 if ok, -1 if failure (name too long) */ int set_dest(ARCHD *arcn, char *dest_dir, int dir_len) { if (fix_path(arcn->name, &(arcn->nlen), dest_dir, dir_len) < 0) return(-1); /* * It is really hard to deal with symlinks here, we cannot be sure * if the name they point was moved (or will be moved). It is best to * leave them alone. */ if ((arcn->type != PAX_HLK) && (arcn->type != PAX_HRG)) return(0); if (fix_path(arcn->ln_name, &(arcn->ln_nlen), dest_dir, dir_len) < 0) return(-1); return(0); } /* * fix_path * concatenate dir_name and or_name and store the result in or_name (if * it fits). This is one ugly function. * Return: * 0 if ok, -1 if the final name is too long */ static int fix_path(char *or_name, int *or_len, char *dir_name, int dir_len) { char *src; char *dest; char *start; int len; /* * we shift the or_name to the right enough to tack in the dir_name * at the front. We make sure we have enough space for it all before * we start. since dest always ends in a slash, we skip of or_name * if it also starts with one. */ start = or_name; src = start + *or_len; dest = src + dir_len; if (*start == '/') { ++start; --dest; } if ((len = dest - or_name) > PAXPATHLEN) { paxwarn(1, "File name %s/%s, too long", dir_name, start); return(-1); } *or_len = len; /* * enough space, shift */ while (src >= start) *dest-- = *src--; src = dir_name + dir_len - 1; /* * splice in the destination directory name */ while (src >= dir_name) *dest-- = *src--; *(or_name + len) = '\0'; return(0); } /* * rep_name() * walk down the list of replacement strings applying each one in order. * when we find one with a successful substitution, we modify the name * as specified. if required, we print the results. if the resulting name * is empty, we will skip this archive member. We use the regexp(3) * routines (regexp() ought to win a prize as having the most cryptic * library function manual page). * --Parameters-- * name is the file name we are going to apply the regular expressions to * (and may be modified) * nsize is the size of the name buffer. * nlen is the length of this name (and is modified to hold the length of * the final string). * prnt is a flag that says whether to print the final result. * Return: * 0 if substitution was successful, 1 if we are to skip the file (the name * ended up empty) */ static int rep_name(char *name, size_t nsize, int *nlen, int prnt) { REPLACE *pt; char *inpt; char *outpt; char *endpt; char *rpt; int found = 0; int res; regmatch_t pm[MAXSUBEXP]; char nname[PAXPATHLEN+1]; /* final result of all replacements */ char buf1[PAXPATHLEN+1]; /* where we work on the name */ /* * copy the name into buf1, where we will work on it. We need to keep * the orig string around so we can print out the result of the final * replacement. We build up the final result in nname. inpt points at * the string we apply the regular expression to. prnt is used to * suppress printing when we handle replacements on the link field * (the user already saw that substitution go by) */ pt = rephead; (void)strlcpy(buf1, name, sizeof(buf1)); inpt = buf1; outpt = nname; endpt = outpt + PAXPATHLEN; /* * try each replacement string in order */ while (pt != NULL) { do { char *oinpt = inpt; /* * check for a successful substitution, if not go to * the next pattern, or cleanup if we were global */ if (regexec(&(pt->rcmp), inpt, MAXSUBEXP, pm, 0) != 0) break; /* * ok we found one. We have three parts, the prefix * which did not match, the section that did and the * tail (that also did not match). Copy the prefix to * the final output buffer (watching to make sure we * do not create a string too long). */ found = 1; rpt = inpt + pm[0].rm_so; while ((inpt < rpt) && (outpt < endpt)) *outpt++ = *inpt++; if (outpt == endpt) break; /* * for the second part (which matched the regular * expression) apply the substitution using the * replacement string and place it the prefix in the * final output. If we have problems, skip it. */ if ((res = resub(&(pt->rcmp),pm,pt->nstr,oinpt,outpt,endpt)) < 0) { if (prnt) paxwarn(1, "Replacement name error %s", name); return(1); } outpt += res; /* * we set up to look again starting at the first * character in the tail (of the input string right * after the last character matched by the regular * expression (inpt always points at the first char in * the string to process). If we are not doing a global * substitution, we will use inpt to copy the tail to * the final result. Make sure we do not overrun the * output buffer */ inpt += pm[0].rm_eo - pm[0].rm_so; if ((outpt == endpt) || (*inpt == '\0')) break; /* * if the user wants global we keep trying to * substitute until it fails, then we are done. */ } while (pt->flgs & GLOB); if (found) break; /* * a successful substitution did NOT occur, try the next one */ pt = pt->fow; } if (found) { /* * we had a substitution, copy the last tail piece (if there is * room) to the final result */ while ((outpt < endpt) && (*inpt != '\0')) *outpt++ = *inpt++; *outpt = '\0'; if ((outpt == endpt) && (*inpt != '\0')) { if (prnt) paxwarn(1,"Replacement name too long %s >> %s", name, nname); return(1); } /* * inform the user of the result if wanted */ if (prnt && (pt->flgs & PRNT)) { if (*nname == '\0') (void)fprintf(stderr,"%s >> \n", name); else (void)fprintf(stderr,"%s >> %s\n", name, nname); } /* * if empty inform the caller this file is to be skipped * otherwise copy the new name over the orig name and return */ if (*nname == '\0') return(1); *nlen = strlcpy(name, nname, nsize); } return(0); } /* * resub() * apply the replacement to the matched expression. expand out the old * style ed(1) subexpression expansion. * Return: * -1 if error, or the number of characters added to the destination. */ static int resub(regex_t *rp, regmatch_t *pm, char *src, char *inpt, char *dest, char *destend) { char *spt; char *dpt; char c; regmatch_t *pmpt; int len; int subexcnt; spt = src; dpt = dest; subexcnt = rp->re_nsub; while ((dpt < destend) && ((c = *spt++) != '\0')) { /* * see if we just have an ordinary replacement character * or we refer to a subexpression. */ if (c == '&') { pmpt = pm; } else if ((c == '\\') && (*spt >= '0') && (*spt <= '9')) { /* * make sure there is a subexpression as specified */ if ((len = *spt++ - '0') > subexcnt) return(-1); pmpt = pm + len; } else { /* * Ordinary character, just copy it */ if ((c == '\\') && (*spt != '\0')) c = *spt++; *dpt++ = c; continue; } /* * continue if the subexpression is bogus */ if ((pmpt->rm_so < 0) || (pmpt->rm_eo < 0) || ((len = pmpt->rm_eo - pmpt->rm_so) <= 0)) continue; /* * copy the subexpression to the destination. * fail if we run out of space or the match string is damaged */ if (len > (destend - dpt)) return (-1); strncpy(dpt, inpt + pmpt->rm_so, len); dpt += len; } return(dpt - dest); }