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      1 /*	$NetBSD: libdm-string.c,v 1.1.1.2 2009/12/02 00:26:08 haad Exp $	*/
      2 
      3 /*
      4  * Copyright (C) 2006-2007 Red Hat, Inc. All rights reserved.
      5  *
      6  * This file is part of the device-mapper userspace tools.
      7  *
      8  * This copyrighted material is made available to anyone wishing to use,
      9  * modify, copy, or redistribute it subject to the terms and conditions
     10  * of the GNU Lesser General Public License v.2.1.
     11  *
     12  * You should have received a copy of the GNU Lesser General Public License
     13  * along with this program; if not, write to the Free Software Foundation,
     14  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
     15  */
     16 
     17 #include "dmlib.h"
     18 #include "libdevmapper.h"
     19 
     20 #include <ctype.h>
     21 
     22 /*
     23  * consume characters while they match the predicate function.
     24  */
     25 static char *_consume(char *buffer, int (*fn) (int))
     26 {
     27 	while (*buffer && fn(*buffer))
     28 		buffer++;
     29 
     30 	return buffer;
     31 }
     32 
     33 static int _isword(int c)
     34 {
     35 	return !isspace(c);
     36 }
     37 
     38 /*
     39  * Split buffer into NULL-separated words in argv.
     40  * Returns number of words.
     41  */
     42 int dm_split_words(char *buffer, unsigned max,
     43 		   unsigned ignore_comments __attribute((unused)),
     44 		   char **argv)
     45 {
     46 	unsigned arg;
     47 
     48 	for (arg = 0; arg < max; arg++) {
     49 		buffer = _consume(buffer, isspace);
     50 		if (!*buffer)
     51 			break;
     52 
     53 		argv[arg] = buffer;
     54 		buffer = _consume(buffer, _isword);
     55 
     56 		if (*buffer) {
     57 			*buffer = '\0';
     58 			buffer++;
     59 		}
     60 	}
     61 
     62 	return arg;
     63 }
     64 
     65 /*
     66  * Remove hyphen quoting from a component of a name.
     67  * NULL-terminates the component and returns start of next component.
     68  */
     69 static char *_unquote(char *component)
     70 {
     71 	char *c = component;
     72 	char *o = c;
     73 	char *r;
     74 
     75 	while (*c) {
     76 		if (*(c + 1)) {
     77 			if (*c == '-') {
     78 				if (*(c + 1) == '-')
     79 					c++;
     80 				else
     81 					break;
     82 			}
     83 		}
     84 		*o = *c;
     85 		o++;
     86 		c++;
     87 	}
     88 
     89 	r = (*c) ? c + 1 : c;
     90 	*o = '\0';
     91 
     92 	return r;
     93 }
     94 
     95 int dm_split_lvm_name(struct dm_pool *mem, const char *dmname,
     96 		      char **vgname, char **lvname, char **layer)
     97 {
     98 	if (mem && !(*vgname = dm_pool_strdup(mem, dmname)))
     99 		return 0;
    100 
    101 	_unquote(*layer = _unquote(*lvname = _unquote(*vgname)));
    102 
    103 	return 1;
    104 }
    105 
    106 /*
    107  * On error, up to glibc 2.0.6, snprintf returned -1 if buffer was too small;
    108  * From glibc 2.1 it returns number of chars (excl. trailing null) that would
    109  * have been written had there been room.
    110  *
    111  * dm_snprintf reverts to the old behaviour.
    112  */
    113 int dm_snprintf(char *buf, size_t bufsize, const char *format, ...)
    114 {
    115 	int n;
    116 	va_list ap;
    117 
    118 	va_start(ap, format);
    119 	n = vsnprintf(buf, bufsize, format, ap);
    120 	va_end(ap);
    121 
    122 	if (n < 0 || ((unsigned) n + 1 > bufsize))
    123 		return -1;
    124 
    125 	return n;
    126 }
    127 
    128 char *dm_basename(const char *path)
    129 {
    130 	char *p = strrchr(path, '/');
    131 
    132 	return p ? p + 1 : (char *) path;
    133 }
    134 
    135 int dm_asprintf(char **result, const char *format, ...)
    136 {
    137 	int n, ok = 0, size = 32;
    138 	va_list ap;
    139 	char *buf = dm_malloc(size);
    140 
    141 	*result = 0;
    142 
    143 	if (!buf)
    144 		return -1;
    145 
    146 	while (!ok) {
    147 		va_start(ap, format);
    148 		n = vsnprintf(buf, size, format, ap);
    149 		if (0 <= n && n < size)
    150 			ok = 1;
    151 		else {
    152 			dm_free(buf);
    153 			size *= 2;
    154 			buf = dm_malloc(size);
    155 			if (!buf)
    156 				return -1;
    157 		};
    158 		va_end(ap);
    159 	}
    160 
    161 	*result = dm_strdup(buf);
    162 	dm_free(buf);
    163 	return n + 1;
    164 }
    165