diff options
Diffstat (limited to 'lib/argv_split.c')
-rw-r--r-- | lib/argv_split.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/lib/argv_split.c b/lib/argv_split.c new file mode 100644 index 0000000..4096ed4 --- /dev/null +++ b/lib/argv_split.c @@ -0,0 +1,105 @@ +/* + * Helper function for splitting a string into an argv-like array. + */ + +#include <linux/kernel.h> +#include <linux/ctype.h> +#include <linux/bug.h> + +static const char *skip_sep(const char *cp) +{ + while (*cp && isspace(*cp)) + cp++; + + return cp; +} + +static const char *skip_arg(const char *cp) +{ + while (*cp && !isspace(*cp)) + cp++; + + return cp; +} + +static int count_argc(const char *str) +{ + int count = 0; + + while (*str) { + str = skip_sep(str); + if (*str) { + count++; + str = skip_arg(str); + } + } + + return count; +} + +/** + * argv_free - free an argv + * @argv - the argument vector to be freed + * + * Frees an argv and the strings it points to. + */ +void argv_free(char **argv) +{ + char **p; + for (p = argv; *p; p++) + kfree(*p); + + kfree(argv); +} +EXPORT_SYMBOL(argv_free); + +/** + * argv_split - split a string at whitespace, returning an argv + * @gfp: the GFP mask used to allocate memory + * @str: the string to be split + * @argcp: returned argument count + * + * Returns an array of pointers to strings which are split out from + * @str. This is performed by strictly splitting on white-space; no + * quote processing is performed. Multiple whitespace characters are + * considered to be a single argument separator. The returned array + * is always NULL-terminated. Returns NULL on memory allocation + * failure. + */ +char **argv_split(gfp_t gfp, const char *str, int *argcp) +{ + int argc = count_argc(str); + char **argv = kzalloc(sizeof(*argv) * (argc+1), gfp); + char **argvp; + + if (argv == NULL) + goto out; + + *argcp = argc; + argvp = argv; + + while (*str) { + str = skip_sep(str); + + if (*str) { + const char *p = str; + char *t; + + str = skip_arg(str); + + t = kstrndup(p, str-p, gfp); + if (t == NULL) + goto fail; + *argvp++ = t; + } + } + *argvp = NULL; + + out: + return argv; + + fail: + argv_free(argv); + return NULL; +} +EXPORT_SYMBOL(argv_split); |