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Diffstat (limited to 'gnu/usr.bin/cpio/userspec.c')
-rw-r--r-- | gnu/usr.bin/cpio/userspec.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/gnu/usr.bin/cpio/userspec.c b/gnu/usr.bin/cpio/userspec.c new file mode 100644 index 0000000..44d7d91 --- /dev/null +++ b/gnu/usr.bin/cpio/userspec.c @@ -0,0 +1,180 @@ +/* userspec.c -- Parse a user and group string. + Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +/* Written by David MacKenzie <djm@gnu.ai.mit.edu>. */ + +#include <stdio.h> +#include <sys/types.h> +#include <pwd.h> +#include <grp.h> + +#if defined(STDC_HEADERS) || defined(HAVE_STRING_H) +#include <string.h> +#ifndef index +#define index strchr +#endif +#else +#include <strings.h> +#endif + +#ifdef STDC_HEADERS +#include <stdlib.h> +#else +char *malloc (); +#endif + +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif + +#ifndef _POSIX_VERSION +struct passwd *getpwnam (); +struct group *getgrnam (); +struct group *getgrgid (); +#endif + +#ifdef _POSIX_SOURCE +#define endpwent() +#define endgrent() +#endif + +#define isdigit(c) ((c) >= '0' && (c) <= '9') + +char *strdup (); +static int isnumber (); + +/* Extract from NAME, which has the form "[user][:.][group]", + a USERNAME, UID U, GROUPNAME, and GID G. + Either user or group, or both, must be present. + If the group is omitted but the ":" or "." separator is given, + use the given user's login group. + + USERNAME and GROUPNAME will be in newly malloc'd memory. + Either one might be NULL instead, indicating that it was not + given and the corresponding numeric ID was left unchanged. + Might write NULs into NAME. + + Return NULL if successful, a static error message string if not. */ + +char * +parse_user_spec (name, uid, gid, username, groupname) + char *name; + uid_t *uid; + gid_t *gid; + char **username, **groupname; +{ + static char *tired = "virtual memory exhausted"; + struct passwd *pwd; + struct group *grp; + char *cp; + int use_login_group = 0; + + *username = *groupname = NULL; + + /* Check whether a group is given. */ + cp = index (name, ':'); + if (cp == NULL) + cp = index (name, '.'); + if (cp != NULL) + { + *cp++ = '\0'; + if (*cp == '\0') + { + if (cp == name + 1) + /* Neither user nor group given, just "." or ":". */ + return "can not omit both user and group"; + else + /* "user.". */ + use_login_group = 1; + } + else + { + /* Explicit group. */ + *groupname = strdup (cp); + if (*groupname == NULL) + return tired; + grp = getgrnam (cp); + if (grp == NULL) + { + if (!isnumber (cp)) + return "invalid group"; + *gid = atoi (cp); + } + else + *gid = grp->gr_gid; + endgrent (); /* Save a file descriptor. */ + } + } + + /* Parse the user name, now that any group has been removed. */ + + if (name[0] == '\0') + /* No user name was given, just a group. */ + return NULL; + + *username = strdup (name); + if (*username == NULL) + return tired; + + pwd = getpwnam (name); + if (pwd == NULL) + { + if (!isnumber (name)) + return "invalid user"; + if (use_login_group) + return "cannot get the login group of a numeric UID"; + *uid = atoi (name); + } + else + { + *uid = pwd->pw_uid; + if (use_login_group) + { + *gid = pwd->pw_gid; + grp = getgrgid (pwd->pw_gid); + if (grp == NULL) + { + *groupname = malloc (15); + if (*groupname == NULL) + return tired; + sprintf (*groupname, "%u", pwd->pw_gid); + } + else + { + *groupname = strdup (grp->gr_name); + if (*groupname == NULL) + return tired; + } + endgrent (); + } + } + endpwent (); + return NULL; +} + +/* Return nonzero if STR represents an unsigned decimal integer, + otherwise return 0. */ + +static int +isnumber (str) + char *str; +{ + for (; *str; str++) + if (!isdigit (*str)) + return 0; + return 1; +} |