]>
git.ipfire.org Git - people/ms/u-boot.git/blob - common/cmd_setexpr.c
2 * Copyright 2008 Freescale Semiconductor, Inc.
3 * Copyright 2013 Wolfgang Denk <wd@denx.de>
5 * SPDX-License-Identifier: GPL-2.0+
9 * This file provides a shell like 'expr' function to return.
16 static ulong
get_arg(char *s
, int w
)
21 * if the parameter starts with a '*' then assume
22 * it is a pointer to the value we want
26 p
= (ulong
*)simple_strtoul(&s
[1], NULL
, 16);
28 case 1: return((ulong
)(*(uchar
*)p
));
29 case 2: return((ulong
)(*(ushort
*)p
));
34 return simple_strtoul(s
, NULL
, 16);
42 #define SLRE_BUFSZ 16384
43 #define SLRE_PATSZ 4096
46 * memstr - Find the first substring in memory
47 * @s1: The string to be searched
48 * @s2: The string to search for
50 * Similar to and based on strstr(),
51 * but strings do not need to be NUL terminated.
53 static char *memstr(const char *s1
, int l1
, const char *s2
, int l2
)
60 if (!memcmp(s1
, s2
, l2
))
67 static char *substitute(char *string
, /* string buffer */
68 int *slen
, /* current string length */
69 int ssize
, /* string bufer size */
70 const char *old
,/* old (replaced) string */
71 int olen
, /* length of old string */
72 const char *new,/* new (replacement) string */
73 int nlen
) /* length of new string */
75 char *p
= memstr(string
, *slen
, old
, olen
);
80 debug("## Match at pos %ld: match len %d, subst len %d\n",
81 (long)(p
- string
), olen
, nlen
);
83 /* make sure replacement matches */
84 if (*slen
+ nlen
- olen
> ssize
) {
85 printf("## error: substitution buffer overflow\n");
89 /* move tail if needed */
93 len
= (olen
> nlen
) ? olen
: nlen
;
95 tail
= ssize
- (p
+ len
- string
);
97 debug("## tail len %d\n", tail
);
99 memmove(p
+ nlen
, p
+ olen
, tail
);
102 /* insert substitue */
103 memcpy(p
, new, nlen
);
105 *slen
+= nlen
- olen
;
111 * Perform regex operations on a environment variable
113 * Returns 0 if OK, 1 in case of errors.
115 static int regex_sub(const char *name
,
116 const char *r
, const char *s
, const char *t
,
120 char data
[SLRE_BUFSZ
];
123 int res
, len
, nlen
, loop
;
128 if (slre_compile(&slre
, r
) == 0) {
129 printf("Error compiling regex: %s\n", slre
.err_str
);
134 value
= getenv(name
);
137 printf("## Error: variable \"%s\" not defined\n", name
);
143 debug("REGEX on %s=%s\n", name
, t
);
144 debug("REGEX=\"%s\", SUBST=\"%s\", GLOBAL=%d\n",
145 r
, s
? s
: "<NULL>", global
);
148 if (len
+ 1 > SLRE_BUFSZ
) {
149 printf("## error: subst buffer overflow: have %d, need %d\n",
150 SLRE_BUFSZ
, len
+ 1);
161 for (loop
= 0;; loop
++) {
162 struct cap caps
[slre
.num_caps
+ 2];
163 char nbuf
[SLRE_PATSZ
];
168 (void) memset(caps
, 0, sizeof(caps
));
170 res
= slre_match(&slre
, datap
, len
, caps
);
172 debug("Result: %d\n", res
);
174 for (i
= 0; i
< slre
.num_caps
; i
++) {
175 if (caps
[i
].len
> 0) {
176 debug("Substring %d: [%.*s]\n", i
,
177 caps
[i
].len
, caps
[i
].ptr
);
183 printf("%s: No match\n", t
);
190 debug("## MATCH ## %s\n", data
);
193 printf("%s=%s\n", name
, t
);
200 if (nlen
+ 1 >= SLRE_PATSZ
) {
201 printf("## error: pattern buffer overflow: have %d, need %d\n",
202 SLRE_BUFSZ
, nlen
+ 1);
207 debug("## SUBST(1) ## %s\n", nbuf
);
210 * Handle back references
212 * Support for \0 ... \9, where \0 is the
213 * whole matched pattern (similar to &).
215 * Implementation is a bit simpleminded as
216 * backrefs are substituted sequentially, one
217 * by one. This will lead to somewhat
218 * unexpected results if the replacement
219 * strings contain any \N strings then then
220 * may get substitued, too. We accept this
221 * restriction for the sake of simplicity.
223 for (i
= 0; i
< 10; ++i
) {
229 if (caps
[i
].len
== 0)
234 debug("## BACKREF %d: replace \"%.*s\" by \"%.*s\" in \"%s\"\n",
237 caps
[i
].len
, caps
[i
].ptr
,
241 char *p
= memstr(np
, nlen
, backref
, 2);
246 np
= substitute(np
, &nlen
,
249 caps
[i
].ptr
, caps
[i
].len
);
255 debug("## SUBST(2) ## %s\n", nbuf
);
257 datap
= substitute(datap
, &len
, SLRE_BUFSZ
,
264 debug("## REMAINDER: %s\n", datap
);
266 debug("## RESULT: %s\n", data
);
271 debug("## FINAL (now setenv()) : %s\n", data
);
273 printf("%s=%s\n", name
, data
);
275 return setenv(name
, data
);
279 static int do_setexpr(cmd_tbl_t
*cmdtp
, int flag
, int argc
, char * const argv
[])
286 * We take 3, 5, or 6 arguments:
287 * 3 : setexpr name value
288 * 5 : setexpr name val1 op val2
289 * setexpr name [g]sub r s
290 * 6 : setexpr name [g]sub r s t
293 /* > 6 already tested by max command args */
294 if ((argc
< 3) || (argc
== 4))
295 return CMD_RET_USAGE
;
297 w
= cmd_get_data_size(argv
[0], 4);
299 a
= get_arg(argv
[2], w
);
301 /* plain assignment: "setexpr name value" */
303 setenv_hex(argv
[1], a
);
307 /* 5 or 6 args (6 args only with [g]sub) */
310 * rexep handling: "setexpr name [g]sub r s [t]"
311 * with 5 args, "t" will be NULL
313 if (strcmp(argv
[2], "gsub") == 0)
314 return regex_sub(argv
[1], argv
[3], argv
[4], argv
[5], 1);
316 if (strcmp(argv
[2], "sub") == 0)
317 return regex_sub(argv
[1], argv
[3], argv
[4], argv
[5], 0);
320 /* standard operators: "setexpr name val1 op val2" */
322 return CMD_RET_USAGE
;
324 if (strlen(argv
[3]) != 1)
325 return CMD_RET_USAGE
;
327 b
= get_arg(argv
[4], w
);
329 switch (argv
[3][0]) {
355 printf("invalid op\n");
359 setenv_hex(argv
[1], value
);
365 setexpr
, 6, 0, do_setexpr
,
366 "set environment variable as the result of eval expression",
367 "[.b, .w, .l] name [*]value1 <op> [*]value2\n"
368 " - set environment variable 'name' to the result of the evaluated\n"
369 " expression specified by <op>. <op> can be &, |, ^, +, -, *, /, %\n"
370 " size argument is only meaningful if value1 and/or value2 are\n"
371 " memory addresses (*)\n"
372 "setexpr[.b, .w, .l] name [*]value\n"
373 " - load a value into a variable"
376 "setexpr name gsub r s [t]\n"
377 " - For each substring matching the regular expression <r> in the\n"
378 " string <t>, substitute the string <s>. The result is\n"
379 " assigned to <name>. If <t> is not supplied, use the old\n"
381 "setexpr name sub r s [t]\n"
382 " - Just like gsub(), but replace only the first matching substring"