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authorRob Landley <rob@landley.net>2014-11-14 15:53:17 -0600
committerRob Landley <rob@landley.net>2014-11-14 15:53:17 -0600
commit222fc81c91ab882279da53fe7f3de20ff4b2ce5e (patch)
tree92b7cd45611f8711ce97b929b73e8aad0e90b515 /toys
parentcb652fa275c1806277ff07a98c864dc8c0335e0f (diff)
downloadtoybox-222fc81c91ab882279da53fe7f3de20ff4b2ce5e.tar.gz
sed: implement s & and \1 backrefs.
Diffstat (limited to 'toys')
-rw-r--r--toys/pending/sed.c95
1 files changed, 70 insertions, 25 deletions
diff --git a/toys/pending/sed.c b/toys/pending/sed.c
index 3d3dcbd3..16cb0810 100644
--- a/toys/pending/sed.c
+++ b/toys/pending/sed.c
@@ -400,16 +400,16 @@ static void walk_pattern(char **pline, long plen)
if (emit(line, len, eol)) break;
} else if (c=='q') break;
else if (c=='s') {
- char *rline = line, *new = logrus->arg2 + (char *)logrus;;
+ char *rline = line, *new = logrus->arg2 + (char *)logrus, *swap, *rswap;
regmatch_t *match = (void *)toybuf;
regex_t *reg = (void *)(logrus->arg1+(char *)logrus);
- unsigned mflags = 0, i = 0, rlen = len, mlen, off, newlen;
+ unsigned mflags = 0, count = 0, rlen = len, mlen, off, newlen;
- // Find match
+ // Find match in remaining line (up to remaining len)
while (!ghostwheel(reg, rline, rlen, 10, match, mflags)) {
mflags = REG_NOTBOL;
- // Zero length matches don't count immediately after last match
+ // Zero length matches don't count immediately after a previous match
mlen = match[0].rm_eo-match[0].rm_so;
if (!mlen && !match[0].rm_so) {
if (!rlen--) break;
@@ -417,29 +417,68 @@ static void walk_pattern(char **pline, long plen)
continue;
}
- // Replace only a specific match?
+ // If we're replacing only a specific match, skip if this isn't it
off = logrus->sflags>>3;
- if (off && off != ++i) {
+ if (off && off != ++count) {
rline += match[0].rm_eo;
rlen -= match[0].rm_eo;
continue;
}
- // The strlen() and memcpy don't support \1 or & yet.
- newlen = strlen(new);
+ // newlen = strlen(new) but with \1 and & and printf escapes
+ for (off = newlen = 0; new[off]; off++) {
+ int cc = 0;
+
+ if (new[off] == '\\') {
+ cc = new[++off] - '0';
+ if (cc < 0 || cc > 9) {
+ newlen += 1+!unescape(new[off]);
+ continue;
+ }
+ } else if (new[off] != '&') {
+ newlen++;
+ continue;
+ }
+ newlen += match[cc].rm_eo-match[cc].rm_so;
+ }
- len = len-mlen+newlen;
- off = rline-line;
- line = xrealloc(line, len+1);
- rline = line+off;
+ // 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);
+ memcpy(swap, line, (rline-line)+match[0].rm_so);
+ memcpy(rswap+match[0].rm_so+newlen, rline+match[0].rm_eo,
+ (rlen -= match[0].rm_eo)+1);
+
+ // copy in new replacement text
+ rswap += match[0].rm_so;
+ for (off = mlen = 0; new[off]; off++) {
+ int cc = 0, ll;
+
+ if ((rswap[mlen++] = new[off]) == '\\') {
+ cc = new[++off] - '0';
+ if (cc<0 || cc>9) {
+ cc = unescape(new[off]);
+ if (cc) rswap[mlen-1] = cc;
+ else rswap[mlen++] = new[off];
+
+ continue;
+ } else if (match[cc].rm_so == -1) error_exit("no s//\\%d/", cc);
+ } else if (new[off] != '&') continue;
+
+ ll = match[cc].rm_eo-match[cc].rm_so;
+ memcpy(rswap+(--mlen), rline+match[cc].rm_so, ll);
+ mlen += ll;
+ }
- rlen -= match[0].rm_eo;
- memmove(rline+match[0].rm_so+newlen, rline+match[0].rm_eo, rlen+1);
- memcpy(rline+match[0].rm_so, new, newlen);
- rline += newlen+match[0].rm_so;
+ rline = rswap+newlen;
+ free(line);
+ line = swap;
+ len = rlen+(rline-line);
- // flag g
+ // Stop after first substitution unless we have flag g
if (!(logrus->sflags & 2)) break;
}
@@ -700,9 +739,7 @@ static void jewel_of_judgement(char **pline, long len)
else if (c == '}') {
if (!TT.nextlen--) break;
} else if (c == 's') {
- void *merlin, *fiona;
- int end;
- char delim = 0;
+ char *merlin, *fiona, delim = 0;
// s/pattern/replacement/flags
@@ -711,20 +748,28 @@ static void jewel_of_judgement(char **pline, long len)
merlin = line;
if (-1 == unescape_delimited_string(&line, &delim)) goto brand;
- // get replacement
+ // get replacement - don't replace escapes because \1 and \& need
+ // processing later, after we replace \\ with \ we can't tell \\1 from \1
fiona = line;
- if (-1 == (end = unescape_delimited_string(&line, &delim))) goto brand;
+ while (*line != delim) {
+ if (!*line) goto brand;
+ if (*line == '\\') {
+ if (!line[1]) goto brand;
+ line += 2;
+ } else line++;
+ }
+
corwin->arg2 = corwin->arg1 + sizeof(regex_t);
- reg = extend_string((void *)&corwin, fiona, corwin->arg2, end);
+ reg = extend_string((void *)&corwin, fiona, corwin->arg2, line-fiona)+1;
// get flags
- for (; *line && *line != ';'; line++) {
+ for (line++; *line && *line != ';'; line++) {
long l;
if (isspace(*line)) continue;
if (0 <= (l = stridx("igp", *line))) corwin->sflags |= 1<<l;
- else if (!corwin->sflags >> 3 && 0<(l = strtol(line+end, &line, 10))) {
+ else if (!corwin->sflags >> 3 && 0<(l = strtol(line, &line, 10))) {
corwin->sflags |= l << 3;
line--;
} else if (*line == 'w') break;