diff options
| -rw-r--r-- | cmd/setexpr.c | 156 |
1 files changed, 98 insertions, 58 deletions
diff --git a/cmd/setexpr.c b/cmd/setexpr.c index dd9c2574fdc..fe3435b4d99 100644 --- a/cmd/setexpr.c +++ b/cmd/setexpr.c @@ -58,9 +58,6 @@ static ulong get_arg(char *s, int w) #include <slre.h> -#define SLRE_BUFSZ 16384 -#define SLRE_PATSZ 4096 - /* * memstr - Find the first substring in memory * @s1: The string to be searched @@ -83,13 +80,24 @@ static char *memstr(const char *s1, int l1, const char *s2, int l2) return NULL; } -static char *substitute(char *string, /* string buffer */ - int *slen, /* current string length */ - int ssize, /* string bufer size */ - const char *old,/* old (replaced) string */ - int olen, /* length of old string */ - const char *new,/* new (replacement) string */ - int nlen) /* length of new string */ +/** + * substitute() - Substitute part of one string with another + * + * This updates @string so that the first occurrence of @old is replaced with + * @new + * + * @string: String buffer containing string to update at the start + * @slen: Pointer to current string length, updated on success + * @ssize: Size of string buffer + * @old: Old string to find in the buffer (no terminator needed) + * @olen: Length of @old excluding terminator + * @new: New string to replace @old with + * @nlen: Length of @new excluding terminator + * @return pointer to immediately after the copied @new in @string, or NULL if + * no replacement took place + */ +static char *substitute(char *string, int *slen, int ssize, + const char *old, int olen, const char *new, int nlen) { char *p = memstr(string, *slen, old, olen); @@ -118,7 +126,7 @@ static char *substitute(char *string, /* string buffer */ memmove(p + nlen, p + olen, tail); } - /* insert substitue */ + /* insert substitute */ memcpy(p, new, nlen); *slen += nlen - olen; @@ -126,52 +134,33 @@ static char *substitute(char *string, /* string buffer */ return p + nlen; } -/* - * Perform regex operations on a environment variable +/** + * regex_sub() - Replace a regex pattern with a string * - * Returns 0 if OK, 1 in case of errors. + * @data: Buffer containing the string to update + * @data_size: Size of buffer (must be large enough for the new string) + * @nbuf: Back-reference buffer + * @nbuf_size: Size of back-reference buffer (must be larger enough for @s plus + * all back-reference expansions) + * @r: Regular expression to find + * @s: String to replace with + * @global: true to replace all matches in @data, false to replace just the + * first + * @return 0 if OK, 1 on error */ -static int regex_sub(const char *name, - const char *r, const char *s, const char *t, - int global) +static int regex_sub(char *data, uint data_size, char *nbuf, uint nbuf_size, + const char *r, const char *s, bool global) { struct slre slre; - char data[SLRE_BUFSZ]; char *datap = data; - const char *value; int res, len, nlen, loop; - if (name == NULL) - return 1; - if (slre_compile(&slre, r) == 0) { printf("Error compiling regex: %s\n", slre.err_str); return 1; } - if (t == NULL) { - value = env_get(name); - - if (value == NULL) { - printf("## Error: variable \"%s\" not defined\n", name); - return 1; - } - t = value; - } - - debug("REGEX on %s=%s\n", name, t); - debug("REGEX=\"%s\", SUBST=\"%s\", GLOBAL=%d\n", - r, s ? s : "<NULL>", global); - - len = strlen(t); - if (len + 1 > SLRE_BUFSZ) { - printf("## error: subst buffer overflow: have %d, need %d\n", - SLRE_BUFSZ, len + 1); - return 1; - } - - strcpy(data, t); - + len = strlen(data); if (s == NULL) nlen = 0; else @@ -179,7 +168,6 @@ static int regex_sub(const char *name, for (loop = 0;; loop++) { struct cap caps[slre.num_caps + 2]; - char nbuf[SLRE_PATSZ]; const char *old; char *np; int i, olen; @@ -199,7 +187,7 @@ static int regex_sub(const char *name, if (res == 0) { if (loop == 0) { - printf("%s: No match\n", t); + printf("%s: No match\n", data); return 1; } else { break; @@ -208,17 +196,15 @@ static int regex_sub(const char *name, debug("## MATCH ## %s\n", data); - if (s == NULL) { - printf("%s=%s\n", name, t); + if (!s) return 1; - } old = caps[0].ptr; olen = caps[0].len; - if (nlen + 1 >= SLRE_PATSZ) { + if (nlen + 1 >= nbuf_size) { printf("## error: pattern buffer overflow: have %d, need %d\n", - SLRE_BUFSZ, nlen + 1); + nbuf_size, nlen + 1); return 1; } strcpy(nbuf, s); @@ -263,7 +249,7 @@ static int regex_sub(const char *name, break; np = substitute(np, &nlen, - SLRE_PATSZ, + nbuf_size, backref, 2, caps[i].ptr, caps[i].len); @@ -273,9 +259,8 @@ static int regex_sub(const char *name, } debug("## SUBST(2) ## %s\n", nbuf); - datap = substitute(datap, &len, SLRE_BUFSZ, - old, olen, - nbuf, nlen); + datap = substitute(datap, &len, data_size, old, olen, + nbuf, nlen); if (datap == NULL) return 1; @@ -289,6 +274,61 @@ static int regex_sub(const char *name, } debug("## FINAL (now env_set()) : %s\n", data); + return 0; +} + +#define SLRE_BUFSZ 16384 +#define SLRE_PATSZ 4096 + +/* + * Perform regex operations on a environment variable + * + * Returns 0 if OK, 1 in case of errors. + */ +static int regex_sub_var(const char *name, const char *r, const char *s, + const char *t, int global) +{ + struct slre slre; + char data[SLRE_BUFSZ]; + char nbuf[SLRE_PATSZ]; + const char *value; + int len; + int ret; + + if (!name) + return 1; + + if (slre_compile(&slre, r) == 0) { + printf("Error compiling regex: %s\n", slre.err_str); + return 1; + } + + if (!t) { + value = env_get(name); + if (!value) { + printf("## Error: variable \"%s\" not defined\n", name); + return 1; + } + t = value; + } + + debug("REGEX on %s=%s\n", name, t); + debug("REGEX=\"%s\", SUBST=\"%s\", GLOBAL=%d\n", r, s ? s : "<NULL>", + global); + + len = strlen(t); + if (len + 1 > SLRE_BUFSZ) { + printf("## error: subst buffer overflow: have %d, need %d\n", + SLRE_BUFSZ, len + 1); + return 1; + } + + strcpy(data, t); + + ret = regex_sub(data, SLRE_BUFSZ, nbuf, SLRE_PATSZ, r, s, global); + if (ret) + return 1; + printf("%s=%s\n", name, data); return env_set(name, data); @@ -331,10 +371,10 @@ static int do_setexpr(struct cmd_tbl *cmdtp, int flag, int argc, * with 5 args, "t" will be NULL */ if (strcmp(argv[2], "gsub") == 0) - return regex_sub(argv[1], argv[3], argv[4], argv[5], 1); + return regex_sub_var(argv[1], argv[3], argv[4], argv[5], 1); if (strcmp(argv[2], "sub") == 0) - return regex_sub(argv[1], argv[3], argv[4], argv[5], 0); + return regex_sub_var(argv[1], argv[3], argv[4], argv[5], 0); #endif /* standard operators: "setexpr name val1 op val2" */ |