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Commit d84d1cc7 authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Jeremy Fitzhardinge
Browse files

add argv_split() 



argv_split() is a helper function which takes a string, splits it at
whitespace, and returns a NULL-terminated argv vector.  This is
deliberately simple - it does no quote processing of any kind.

[ Seems to me that this is something which is already being done in
  the kernel, but I couldn't find any other implementations, either to
  steal or replace.  Keep an eye out. ]

Signed-off-by: default avatarJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: default avatarChris Wright <chrisw@sous-sol.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
parent 1e66df3e

include/linux/string.h

+3 −0
Original line number Diff line number Diff line
@@ -108,6 +108,9 @@ extern char *kstrdup(const char *s, gfp_t gfp); 
extern char *kstrndup(const char *s, size_t len, gfp_t gfp);

extern void *kmemdup(const void *src, size_t len, gfp_t gfp);



extern char **argv_split(gfp_t gfp, const char *str, int *argcp);

extern void argv_free(char **argv);



#ifdef __cplusplus

}

#endif

lib/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -5,7 +5,7 @@ 
lib-y := ctype.o string.o vsprintf.o cmdline.o \

	 rbtree.o radix-tree.o dump_stack.o \

	 idr.o int_sqrt.o bitmap.o extable.o prio_tree.o \

	 sha1.o irq_regs.o reciprocal_div.o

	 sha1.o irq_regs.o reciprocal_div.o argv_split.o



lib-$(CONFIG_MMU) += ioremap.o

lib-$(CONFIG_SMP) += cpumask.o

lib/argv_split.c

0 → 100644
+105 −0
Original line number Diff line number Diff line 
/*

 * 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);