diff options
| -rw-r--r-- | toys/posix/sed.c | 61 |
1 files changed, 36 insertions, 25 deletions
diff --git a/toys/posix/sed.c b/toys/posix/sed.c index 0c31d2af..d9bb5c94 100644 --- a/toys/posix/sed.c +++ b/toys/posix/sed.c @@ -466,20 +466,21 @@ static void sed_line(char **pline, long plen) break; } else if (c=='s') { - char *rline = line, *new = command->arg2 + (char *)command, *swap, *rswap; + char *rline = line, *new = command->arg2 + (char *)command, *l2 = 0; regmatch_t *match = (void *)toybuf; regex_t *reg = get_regex(command, command->arg1); - int mflags = 0, count = 0, zmatch = 1, rlen = len, mlen, off, newlen; + int mflags = 0, count = 0, l2used = 0, zmatch = 1, l2l = len, + mlen, off, newlen; - // Find match in remaining line (up to remaining len) - while (!regexec0(reg, rline, rlen, 10, match, mflags)) { + // Loop finding match in remaining line (up to remaining len) + while (!regexec0(reg, rline, len-(rline-line), 10, match, mflags)) { mflags = REG_NOTBOL; // Zero length matches don't count immediately after a previous match mlen = match[0].rm_eo-match[0].rm_so; if (!mlen && !zmatch) { - if (!rlen--) break; - rline++; + if (rline-line == len) break; + l2[l2used++] = *rline++; zmatch++; continue; } else zmatch = 0; @@ -487,8 +488,9 @@ static void sed_line(char **pline, long plen) // If we're replacing only a specific match, skip if this isn't it off = command->sflags>>3; if (off && off != ++count) { + memcpy(l2+l2used, rline, match[0].rm_eo); + l2used += match[0].rm_eo; rline += match[0].rm_eo; - rlen -= match[0].rm_eo; continue; } @@ -509,13 +511,15 @@ static void sed_line(char **pline, long plen) newlen += match[cc].rm_eo-match[cc].rm_so; } - // Allocate new size, copy start/end around match. (Can't extend in - // place because backrefs may refer to text after it's overwritten.) - len += newlen-mlen; - swap = xmalloc(len+1); - rswap = swap+(rline-line)+match[0].rm_so; - memcpy(swap, line, (rline-line)+match[0].rm_so); - memcpy(rswap+newlen, rline+match[0].rm_eo, (rlen -= match[0].rm_eo)+1); + // Copy changed data to new string + + // Adjust allocation size of new string, copy data we know we'll keep + l2l += newlen-mlen; + if (newlen>mlen || !l2) l2 = xrealloc(l2, l2l+1); + if (match[0].rm_so) { + memcpy(l2+l2used, rline, match[0].rm_so); + l2used += match[0].rm_so; + } // copy in new replacement text for (off = mlen = 0; new[off]; off++) { @@ -524,33 +528,40 @@ static void sed_line(char **pline, long plen) if (new[off] == '\\') { cc = new[++off] - '0'; if (cc<0 || cc>9) { - if (!(rswap[mlen++] = unescape(new[off]))) - rswap[mlen-1] = new[off]; + if (!(l2[l2used+mlen++] = unescape(new[off]))) + l2[l2used+mlen-1] = new[off]; continue; } else if (cc > reg->re_nsub) error_exit("no s//\\%d/", cc); } else if (new[off] != '&') { - rswap[mlen++] = new[off]; + l2[l2used+mlen++] = new[off]; continue; } - if (match[cc].rm_so == -1) ll = 0; // Empty match. - else { + if (match[cc].rm_so != -1) { ll = match[cc].rm_eo-match[cc].rm_so; - memcpy(rswap+mlen, rline+match[cc].rm_so, ll); + memcpy(l2+l2used+mlen, rline+match[cc].rm_so, ll); + mlen += ll; } - mlen += ll; } - - rline = rswap+newlen; - free(line); - line = swap; + l2used += newlen; + rline += match[0].rm_eo; // Stop after first substitution unless we have flag g if (!(command->sflags & 2)) break; } + // If we made any changes, finish off l2 and swap it for line + if (l2) { + // grab trailing unmatched data and null terminator, swap with original + mlen = len-(rline-line); + memcpy(l2+l2used, rline, mlen+1); + len = l2used + mlen; + free(line); + line = l2; + } + if (mflags) { // flag p if (command->sflags & 4) emit(line, len, eol); |