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Diffstat (limited to 'examples/loadables/id.c')
| -rw-r--r-- | examples/loadables/id.c | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/examples/loadables/id.c b/examples/loadables/id.c new file mode 100644 index 0000000..8773349 --- /dev/null +++ b/examples/loadables/id.c @@ -0,0 +1,328 @@ +/* + * id - POSIX.2 user identity + * + * (INCOMPLETE -- supplementary groups for other users not yet done) + * + * usage: id [-Ggu] [-nr] [user] + * + * The default output format looks something like: + * uid=xxx(chet) gid=xx groups=aa(aname), bb(bname), cc(cname) + */ + +/* + Copyright (C) 1999-2009 Free Software Foundation, Inc. + + This file is part of GNU Bash. + Bash 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 3 of the License, or + (at your option) any later version. + + Bash 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 Bash. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include <config.h> +#include <stdio.h> +#include "bashtypes.h" +#include <pwd.h> +#include <grp.h> +#include "bashansi.h" + +#ifdef HAVE_LIMITS_H +# include <limits.h> +#else +# include <sys/param.h> +#endif + +#if !defined (HAVE_GETPW_DECLS) +extern struct passwd *getpwuid (); +#endif +extern struct group *getgrgid (); + +#include "shell.h" +#include "builtins.h" +#include "stdc.h" +#include "common.h" +#include "bashgetopt.h" + +#define ID_ALLGROUPS 0x001 /* -G */ +#define ID_GIDONLY 0x002 /* -g */ +#define ID_USENAME 0x004 /* -n */ +#define ID_USEREAL 0x008 /* -r */ +#define ID_USERONLY 0x010 /* -u */ + +#define ID_FLAGSET(s) ((id_flags & (s)) != 0) + +static int id_flags; + +static uid_t ruid, euid; +static gid_t rgid, egid; + +static char *id_user; + +static int inituser (); + +static int id_pruser (); +static int id_prgrp (); +static int id_prgroups (); +static int id_prall (); + +int +id_builtin (list) + WORD_LIST *list; +{ + int opt; + char *user; + + id_flags = 0; + reset_internal_getopt (); + while ((opt = internal_getopt (list, "Ggnru")) != -1) + { + switch (opt) + { + case 'G': id_flags |= ID_ALLGROUPS; break; + case 'g': id_flags |= ID_GIDONLY; break; + case 'n': id_flags |= ID_USENAME; break; + case 'r': id_flags |= ID_USEREAL; break; + case 'u': id_flags |= ID_USERONLY; break; + default: + builtin_usage (); + return (EX_USAGE); + } + } + list = loptend; + + user = list ? list->word->word : (char *)NULL; + + /* Check for some invalid option combinations */ + opt = ID_FLAGSET (ID_ALLGROUPS) + ID_FLAGSET (ID_GIDONLY) + ID_FLAGSET (ID_USERONLY); + if (opt > 1 || (opt == 0 && ((id_flags & (ID_USEREAL|ID_USENAME)) != 0))) + { + builtin_usage (); + return (EX_USAGE); + } + + if (list && list->next) + { + builtin_usage (); + return (EX_USAGE); + } + + if (inituser (user) < 0) + return (EXECUTION_FAILURE); + + opt = 0; + if (id_flags & ID_USERONLY) + opt += id_pruser ((id_flags & ID_USEREAL) ? ruid : euid); + else if (id_flags & ID_GIDONLY) + opt += id_prgrp ((id_flags & ID_USEREAL) ? rgid : egid); + else if (id_flags & ID_ALLGROUPS) + opt += id_prgroups (user); + else + opt += id_prall (user); + putchar ('\n'); + fflush (stdout); + + return (opt == 0 ? EXECUTION_SUCCESS : EXECUTION_FAILURE); +} + +static int +inituser (uname) + char *uname; +{ + struct passwd *pwd; + + if (uname) + { + pwd = getpwnam (uname); + if (pwd == 0) + { + builtin_error ("%s: no such user", uname); + return -1; + } + ruid = euid = pwd->pw_uid; + rgid = egid = pwd->pw_gid; + } + else + { + ruid = current_user.uid; + euid = current_user.euid; + rgid = current_user.gid; + egid = current_user.egid; + } + return 0; +} + +/* Print the name or value of user ID UID. */ +static int +id_pruser (uid) + int uid; +{ + struct passwd *pwd = NULL; + int r; + + r = 0; + if (id_flags & ID_USENAME) + { + pwd = getpwuid (uid); + if (pwd == NULL) + r = 1; + } + if (pwd) + printf ("%s", pwd->pw_name); + else + printf ("%u", (unsigned) uid); + + return r; +} + +/* Print the name or value of group ID GID. */ + +static int +id_prgrp (gid) + int gid; +{ + struct group *grp = NULL; + int r; + + r = 0; + if (id_flags & ID_USENAME) + { + grp = getgrgid (gid); + if (grp == NULL) + r = 1; + } + + if (grp) + printf ("%s", grp->gr_name); + else + printf ("%u", (unsigned) gid); + + return r; +} + +static int +id_prgroups (uname) + char *uname; +{ + int *glist, ng, i, r; + + r = 0; + id_prgrp (rgid); + if (egid != rgid) + { + putchar (' '); + id_prgrp (egid); + } + + if (uname) + { + builtin_error ("supplementary groups for other users not yet implemented"); + glist = (int *)NULL; + ng = 0; + r = 1; + } + else + glist = get_group_array (&ng); + + for (i = 0; i < ng; i++) + if (glist[i] != rgid && glist[i] != egid) + { + putchar (' '); + id_prgrp (glist[i]); + } + + return r; +} + +static int +id_prall (uname) + char *uname; +{ + int r, i, ng, *glist; + struct passwd *pwd; + struct group *grp; + + r = 0; + printf ("uid=%u", (unsigned) ruid); + pwd = getpwuid (ruid); + if (pwd == NULL) + r = 1; + else + printf ("(%s)", pwd->pw_name); + + printf (" gid=%u", (unsigned) rgid); + grp = getgrgid (rgid); + if (grp == NULL) + r = 1; + else + printf ("(%s)", grp->gr_name); + + if (euid != ruid) + { + printf (" euid=%u", (unsigned) euid); + pwd = getpwuid (euid); + if (pwd == NULL) + r = 1; + else + printf ("(%s)", pwd->pw_name); + } + + if (egid != rgid) + { + printf (" egid=%u", (unsigned) egid); + grp = getgrgid (egid); + if (grp == NULL) + r = 1; + else + printf ("(%s)", grp->gr_name); + } + + if (uname) + { + builtin_error ("supplementary groups for other users not yet implemented"); + glist = (int *)NULL; + ng = 0; + r = 1; + } + else + glist = get_group_array (&ng); + + if (ng > 0) + printf (" groups="); + for (i = 0; i < ng; i++) + { + if (i > 0) + printf (", "); + printf ("%u", (unsigned) glist[i]); + grp = getgrgid (glist[i]); + if (grp == NULL) + r = 1; + else + printf ("(%s)", grp->gr_name); + } + + return r; +} + +char *id_doc[] = { + "Display information about user." + "", + "Return information about user identity", + (char *)NULL +}; + +struct builtin id_struct = { + "id", + id_builtin, + BUILTIN_ENABLED, + id_doc, + "id [user]\n\tid -G [-n] [user]\n\tid -g [-nr] [user]\n\tid -u [-nr] [user]", + 0 +}; |