vi: allow regular expressions in ':s' commands
BusyBox vi has never supported the use of regular expressions in
search/replace (':s') commands. Implement this using GNU regex
when VI_REGEX_SEARCH is enabled.
The implementation:
- uses basic regular expressions, to match those used in the search
command;
- only supports substitution of back references ('\0' - '\9') in the
replacement string. Any other character following a backslash is
treated as that literal character.
VI_REGEX_SEARCH isn't enabled in the default build. In that case:
function old new delta
colon 4036 4033 -3
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-3) Total: -3 bytes
When VI_REGEX_SEARCH is enabled:
function old new delta
colon 4036 4378 +342
.rodata 108207 108229 +22
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 364/0) Total: 364 bytes
v2: Rebase. Code shrink. Ensure empty replacement string is null terminated.
Signed-off-by: Andrey Dobrovolsky <andrey.dobrovolsky.odessa@gmail.com>
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
parent
c76c78740a
commit
95ac4a48f1
133
editors/vi.c
133
editors/vi.c
|
|
@ -2677,6 +2677,59 @@ static char *expand_args(char *args)
|
|||
# endif
|
||||
#endif /* FEATURE_VI_COLON */
|
||||
|
||||
#if ENABLE_FEATURE_VI_REGEX_SEARCH
|
||||
# define MAX_SUBPATTERN 10 // subpatterns \0 .. \9
|
||||
|
||||
// If the return value is not NULL the caller should free R
|
||||
static char *regex_search(char *q, regex_t *preg, const char *Rorig,
|
||||
size_t *len_F, size_t *len_R, char **R)
|
||||
{
|
||||
regmatch_t regmatch[MAX_SUBPATTERN], *cur_match;
|
||||
char *found = NULL;
|
||||
const char *t;
|
||||
char *r;
|
||||
|
||||
regmatch[0].rm_so = 0;
|
||||
regmatch[0].rm_eo = end_line(q) - q;
|
||||
if (regexec(preg, q, MAX_SUBPATTERN, regmatch, REG_STARTEND) != 0)
|
||||
return found;
|
||||
|
||||
found = q + regmatch[0].rm_so;
|
||||
*len_F = regmatch[0].rm_eo - regmatch[0].rm_so;
|
||||
*R = NULL;
|
||||
|
||||
fill_result:
|
||||
// first pass calculates len_R, second fills R
|
||||
*len_R = 0;
|
||||
for (t = Rorig, r = *R; *t; t++) {
|
||||
size_t len = 1; // default is to copy one char from replace pattern
|
||||
const char *from = t;
|
||||
if (*t == '\\') {
|
||||
from = ++t; // skip backslash
|
||||
if (*t >= '0' && *t < '0' + MAX_SUBPATTERN) {
|
||||
cur_match = regmatch + (*t - '0');
|
||||
if (cur_match->rm_so >= 0) {
|
||||
len = cur_match->rm_eo - cur_match->rm_so;
|
||||
from = q + cur_match->rm_so;
|
||||
}
|
||||
}
|
||||
}
|
||||
*len_R += len;
|
||||
if (*R) {
|
||||
memcpy(r, from, len);
|
||||
r += len;
|
||||
/* *r = '\0'; - xzalloc did it */
|
||||
}
|
||||
}
|
||||
if (*R == NULL) {
|
||||
*R = xzalloc(*len_R + 1);
|
||||
goto fill_result;
|
||||
}
|
||||
|
||||
return found;
|
||||
}
|
||||
#endif /* ENABLE_FEATURE_VI_REGEX_SEARCH */
|
||||
|
||||
// buf must be no longer than MAX_INPUT_LEN!
|
||||
static void colon(char *buf)
|
||||
{
|
||||
|
|
@ -3083,6 +3136,14 @@ static void colon(char *buf)
|
|||
int subs = 0; // number of substitutions
|
||||
# if ENABLE_FEATURE_VI_VERBOSE_STATUS
|
||||
int last_line = 0, lines = 0;
|
||||
# endif
|
||||
# if ENABLE_FEATURE_VI_REGEX_SEARCH
|
||||
regex_t preg;
|
||||
int cflags;
|
||||
char *Rorig;
|
||||
# if ENABLE_FEATURE_VI_UNDO
|
||||
int undo = 0;
|
||||
# endif
|
||||
# endif
|
||||
|
||||
// F points to the "find" pattern
|
||||
|
|
@ -3100,7 +3161,6 @@ static void colon(char *buf)
|
|||
*flags++ = '\0'; // terminate "replace"
|
||||
gflag = *flags;
|
||||
}
|
||||
len_R = strlen(R);
|
||||
|
||||
if (len_F) { // save "find" as last search pattern
|
||||
free(last_search_pattern);
|
||||
|
|
@ -3122,31 +3182,68 @@ static void colon(char *buf)
|
|||
b = e;
|
||||
}
|
||||
|
||||
# if ENABLE_FEATURE_VI_REGEX_SEARCH
|
||||
Rorig = R;
|
||||
cflags = 0;
|
||||
if (ignorecase)
|
||||
cflags = REG_ICASE;
|
||||
memset(&preg, 0, sizeof(preg));
|
||||
if (regcomp(&preg, F, cflags) != 0) {
|
||||
status_line(":s bad search pattern");
|
||||
goto regex_search_end;
|
||||
}
|
||||
# else
|
||||
len_R = strlen(R);
|
||||
# endif
|
||||
|
||||
for (i = b; i <= e; i++) { // so, :20,23 s \0 find \0 replace \0
|
||||
char *ls = q; // orig line start
|
||||
char *found;
|
||||
vc4:
|
||||
# if ENABLE_FEATURE_VI_REGEX_SEARCH
|
||||
found = regex_search(q, &preg, Rorig, &len_F, &len_R, &R);
|
||||
# else
|
||||
found = char_search(q, F, (FORWARD << 1) | LIMITED); // search cur line only for "find"
|
||||
# endif
|
||||
if (found) {
|
||||
uintptr_t bias;
|
||||
// we found the "find" pattern - delete it
|
||||
// For undo support, the first item should not be chained
|
||||
text_hole_delete(found, found + len_F - 1,
|
||||
subs ? ALLOW_UNDO_CHAIN: ALLOW_UNDO);
|
||||
// can't do this above, no undo => no third argument
|
||||
subs++;
|
||||
# if ENABLE_FEATURE_VI_VERBOSE_STATUS
|
||||
if (last_line != i) {
|
||||
last_line = i;
|
||||
++lines;
|
||||
}
|
||||
// This needs to be handled differently depending on
|
||||
// whether or not regex support is enabled.
|
||||
# if ENABLE_FEATURE_VI_REGEX_SEARCH
|
||||
# define TEST_LEN_F len_F // len_F may be zero
|
||||
# define TEST_UNDO1 undo++
|
||||
# define TEST_UNDO2 undo++
|
||||
# else
|
||||
# define TEST_LEN_F 1 // len_F is never zero
|
||||
# define TEST_UNDO1 subs
|
||||
# define TEST_UNDO2 1
|
||||
# endif
|
||||
// insert the "replace" patern
|
||||
bias = string_insert(found, R, ALLOW_UNDO_CHAIN);
|
||||
found += bias;
|
||||
ls += bias;
|
||||
dot = ls;
|
||||
//q += bias; - recalculated anyway
|
||||
if (TEST_LEN_F) // match can be empty, no delete needed
|
||||
text_hole_delete(found, found + len_F - 1,
|
||||
TEST_UNDO1 ? ALLOW_UNDO_CHAIN: ALLOW_UNDO);
|
||||
if (len_R) { // insert the "replace" pattern, if required
|
||||
bias = string_insert(found, R,
|
||||
TEST_UNDO2 ? ALLOW_UNDO_CHAIN: ALLOW_UNDO);
|
||||
found += bias;
|
||||
ls += bias;
|
||||
dot = ls;
|
||||
//q += bias; - recalculated anyway
|
||||
}
|
||||
# if ENABLE_FEATURE_VI_REGEX_SEARCH
|
||||
free(R);
|
||||
# endif
|
||||
if (TEST_LEN_F || len_R) {
|
||||
dot = ls;
|
||||
subs++;
|
||||
# if ENABLE_FEATURE_VI_VERBOSE_STATUS
|
||||
if (last_line != i) {
|
||||
last_line = i;
|
||||
++lines;
|
||||
}
|
||||
# endif
|
||||
}
|
||||
// check for "global" :s/foo/bar/g
|
||||
if (gflag == 'g') {
|
||||
if ((found + len_R) < end_line(ls)) {
|
||||
|
|
@ -3166,6 +3263,10 @@ static void colon(char *buf)
|
|||
status_line("%d substitutions on %d lines", subs, lines);
|
||||
# endif
|
||||
}
|
||||
# if ENABLE_FEATURE_VI_REGEX_SEARCH
|
||||
regex_search_end:
|
||||
regfree(&preg);
|
||||
# endif
|
||||
# endif /* FEATURE_VI_SEARCH */
|
||||
} else if (strncmp(cmd, "version", i) == 0) { // show software version
|
||||
status_line(BB_VER);
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user