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lvm2/lib/misc/lvm-string.c
Dave Wysochanski 15309c57bd Add count_chars and count_chars_len functions, two
generic string utility functions.

--
2007-04-25 18:24:19 +00:00

158 lines
3.1 KiB
C

/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004 Red Hat, Inc. All rights reserved.
*
* This file is part of LVM2.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License v.2.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "lib.h"
#include "lvm-string.h"
#include <ctype.h>
int emit_to_buffer(char **buffer, size_t *size, const char *fmt, ...)
{
int n;
va_list ap;
va_start(ap, fmt);
n = vsnprintf(*buffer, *size, fmt, ap);
va_end(ap);
if (n < 0 || (n == *size))
return 0;
*buffer += n;
*size -= n;
return 1;
}
/*
* Count occurences of 'c' in 'str' until we reach a null char.
*
* Returns:
* len - incremented for each char we encounter, whether 'c' or not.
* count - number of occurences of 'c'
*/
void count_chars(const char *str, size_t *len, int *count,
const char c)
{
const char *ptr;
for (ptr = str; *ptr; ptr++, (*len)++)
if (*ptr == c)
(*count)++;
}
/*
* Count occurences of 'c' in 'str' of length 'size'.
*
* Returns:
* # of occurences of 'c'
*/
unsigned count_chars_len(const char *str, size_t size, const char c)
{
int i;
unsigned count=0;
for (i=0; i < size; i++)
if (str[i] == c)
count++;
return count;
}
/*
* Copies a string, quoting hyphens with hyphens.
*/
static void _quote_hyphens(char **out, const char *src)
{
while (*src) {
if (*src == '-')
*(*out)++ = '-';
*(*out)++ = *src++;
}
}
/*
* <vg>-<lv>-<layer> or if !layer just <vg>-<lv>.
*/
char *build_dm_name(struct dm_pool *mem, const char *vgname,
const char *lvname, const char *layer)
{
size_t len = 1;
int hyphens = 1;
char *r, *out;
count_chars(vgname, &len, &hyphens, '-');
count_chars(lvname, &len, &hyphens, '-');
if (layer && *layer) {
count_chars(layer, &len, &hyphens, '-');
hyphens++;
}
len += hyphens;
if (!(r = dm_pool_alloc(mem, len))) {
log_error("build_dm_name: Allocation failed for %" PRIsize_t
" for %s %s %s.", len, vgname, lvname, layer);
return NULL;
}
out = r;
_quote_hyphens(&out, vgname);
*out++ = '-';
_quote_hyphens(&out, lvname);
if (layer && *layer) {
/* No hyphen if the layer begins with _ e.g. _mlog */
if (*layer != '_')
*out++ = '-';
_quote_hyphens(&out, layer);
}
*out = '\0';
return r;
}
/*
* Device layer names are all of the form <vg>-<lv>-<layer>, any
* other hyphens that appear in these names are quoted with yet
* another hyphen. The top layer of any device has no layer
* name. eg, vg0-lvol0.
*/
int validate_name(const char *n)
{
register char c;
register int len = 0;
if (!n || !*n)
return 0;
/* Hyphen used as VG-LV separator - ambiguity if LV starts with it */
if (*n == '-')
return 0;
if (!strcmp(n, ".") || !strcmp(n, ".."))
return 0;
while ((len++, c = *n++))
if (!isalnum(c) && c != '.' && c != '_' && c != '-' && c != '+')
return 0;
if (len > NAME_LEN)
return 0;
return 1;
}