/* id.c - print real and effective user and group IDs * * Copyright 2012 Sony Network Entertainment, Inc. * * by Tim Bird <tim.bird@am.sony.com> * * See http://opengroup.org/onlinepubs/9699919799/utilities/id.html USE_ID(NEWTOY(id, "nGgru", TOYFLAG_BIN)) config ID bool "id" default y help usage: id [-nGgru] Print user and group ID. -n print names instead of numeric IDs (to be used with -Ggu) -G Show only the group IDs -g Show only the effective group ID -r Show real ID instead of effective ID -u Show only the effective user ID */ #define FOR_id #include "toys.h" static void s_or_u(char *s, unsigned u, int done) { if (toys.optflags & FLAG_n) printf("%s", s); else printf("%u", u); if (done) { xputc('\n'); exit(0); } } static void showid(char *header, unsigned u, char *s) { printf("%s%u(%s)", header, u, s); } struct passwd *xgetpwuid(uid_t uid) { struct passwd *pwd = getpwuid(uid); if (!pwd) error_exit(NULL); return pwd; } struct group *xgetgrgid(gid_t gid) { struct group *group = getgrgid(gid); if (!group) error_exit(NULL); return group; } void id_main(void) { int flags = toys.optflags, i, ngroups; struct passwd *pw; struct group *grp; uid_t uid = getuid(), euid = geteuid(); gid_t gid = getgid(), egid = getegid(), *groups; // check if a username is given if (*toys.optargs) { if (!(pw = getpwnam(*toys.optargs))) error_exit("no such user '%s'", *toys.optargs); uid = euid = pw->pw_uid; gid = egid = pw->pw_gid; } i = toys.optflags & FLAG_r; pw = xgetpwuid(i ? uid : euid); if (flags & FLAG_u) s_or_u(pw->pw_name, pw->pw_uid, 1); grp = xgetgrgid(i ? gid : egid); if (flags & FLAG_g) s_or_u(grp->gr_name, grp->gr_gid, 1); if (!(flags & FLAG_G)) { showid("uid=", pw->pw_uid, pw->pw_name); showid(" gid=", grp->gr_gid, grp->gr_name); if (!i) { if (uid != euid) { pw = xgetpwuid(euid); showid(" euid=", pw->pw_uid, pw->pw_name); } if (gid != egid) { grp = xgetgrgid(egid); showid(" egid=", grp->gr_gid, grp->gr_name); } } showid(" groups=", grp->gr_gid, grp->gr_name); } groups = (gid_t *)toybuf; if (0 >= (ngroups = getgroups(sizeof(toybuf)/sizeof(gid_t), groups))) perror_exit(0); for (i = 0; i < ngroups; i++) { xputc(' '); if (!(grp = getgrgid(groups[i]))) perror_msg(0); else if (flags & FLAG_G) s_or_u(grp->gr_name, grp->gr_gid, 0); else if (grp->gr_gid != egid) showid("", grp->gr_gid, grp->gr_name); } xputc('\n'); }