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Diffstat (limited to 'lib/sgetgrent.c')
| -rw-r--r-- | lib/sgetgrent.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/lib/sgetgrent.c b/lib/sgetgrent.c new file mode 100644 index 0000000..a951be4 --- /dev/null +++ b/lib/sgetgrent.c @@ -0,0 +1,154 @@ +/* + * Copyright (c) 1990 - 1994, Julianne Frances Haugh + * Copyright (c) 1996 - 1998, Marek Michałkiewicz + * Copyright (c) 2005 , Tomasz Kłoczko + * Copyright (c) 2008 , Nicolas François + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the copyright holders or contributors may not be used to + * endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <config.h> + +#ident "$Id$" + +#include <stdio.h> +#include <sys/types.h> +#include <grp.h> +#include "defines.h" +#include "prototypes.h" + +#define NFIELDS 4 + +/* + * list - turn a comma-separated string into an array of (char *)'s + * + * list() converts the comma-separated list of member names into + * an array of character pointers. + * + * WARNING: I profiled this once with and without strchr() calls + * and found that using a register variable and an explicit loop + * works best. For large /etc/group files, this is a major win. + * + * FINALLY added dynamic allocation. Still need to fix sgetsgent(). + * --marekm + */ +static char **list (char *s) +{ + static char **members = 0; + static int size = 0; /* max members + 1 */ + int i; + char **rbuf; + + i = 0; + for (;;) { + /* check if there is room for another pointer (to a group + member name, or terminating NULL). */ + if (i >= size) { + size = i + 100; /* at least: i + 1 */ + if (members) { + rbuf = + realloc (members, size * sizeof (char *)); + } else { + /* for old (before ANSI C) implementations of + realloc() that don't handle NULL properly */ + rbuf = malloc (size * sizeof (char *)); + } + if (!rbuf) { + if (members) + free (members); + members = 0; + size = 0; + return (char **) 0; + } + members = rbuf; + } + if (!s || s[0] == '\0') + break; + members[i++] = s; + while (('\0' != *s) && (',' != *s)) { + s++; + } + if ('\0' != *s) { + *s++ = '\0'; + } + } + members[i] = (char *) 0; + return members; +} + + +struct group *sgetgrent (const char *buf) +{ + static char *grpbuf = 0; + static size_t size = 0; + static char *grpfields[NFIELDS]; + static struct group grent; + int i; + char *cp; + + if (strlen (buf) + 1 > size) { + /* no need to use realloc() here - just free it and + allocate a larger block */ + if (grpbuf) + free (grpbuf); + size = strlen (buf) + 1000; /* at least: strlen(buf) + 1 */ + grpbuf = malloc (size); + if (!grpbuf) { + size = 0; + return 0; + } + } + strcpy (grpbuf, buf); + + cp = strrchr (grpbuf, '\n'); + if (NULL != cp) { + *cp = '\0'; + } + + for (cp = grpbuf, i = 0; (i < NFIELDS) && (NULL != cp); i++) { + grpfields[i] = cp; + cp = strchr (cp, ':'); + if (NULL != cp) { + *cp = '\0'; + cp++; + } + } + if (i < (NFIELDS - 1) || *grpfields[2] == '\0' || cp != NULL) { + return (struct group *) 0; + } + grent.gr_name = grpfields[0]; + grent.gr_passwd = grpfields[1]; + if (get_gid (grpfields[2], &grent.gr_gid) == 0) { + return (struct group *) 0; + } + grent.gr_mem = list (grpfields[3]); + if (NULL == grent.gr_mem) { + return (struct group *) 0; /* out of memory */ + } + + return &grent; +} + |