newlib-cygwin/newlib/libc/argz/argz_insert.c

49 lines
1.1 KiB
C

/* Copyright (C) 2002, 2005 by Red Hat, Incorporated. All rights reserved.
*
* Permission to use, copy, modify, and distribute this software
* is freely granted, provided that this notice is preserved.
*/
#include <errno.h>
#include <sys/types.h>
#include <string.h>
#include <stdlib.h>
#include <argz.h>
#define __need_ptrdiff_t
#include <stddef.h>
error_t
_DEFUN (argz_insert, (argz, argz_len, before, entry),
char **argz _AND
size_t *argz_len _AND
char *before _AND
const char *entry)
{
int len = 0;
ptrdiff_t delta;
if (before == NULL)
return argz_add(argz, argz_len, entry);
if (before < *argz || before >= *argz + *argz_len)
return EINVAL;
while (before != *argz && before[-1])
before--;
/* delta will always be non-negative, and < *argz_len */
delta = before - *argz;
len = strlen(entry) + 1;
if(!(*argz = (char *)realloc(*argz, *argz_len + len)))
return ENOMEM;
memmove(*argz + delta + len, *argz + delta, *argz_len - delta);
memcpy(*argz + delta, entry, len);
*argz_len += len;
return 0;
}