| /* vi: set sw=4 ts=4: |
| * |
| * 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://www.opengroup.org/onlinepubs/009695399/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 |
| */ |
| |
| #include "toys.h" |
| |
| #define FLAG_n (1<<4) |
| #define FLAG_G (1<<3) |
| #define FLAG_g (1<<2) |
| #define FLAG_r (1<<1) |
| #define FLAG_u 1 |
| |
| void pretty_print(struct passwd *pw, struct group *grp, struct group **grps, |
| int n) |
| { |
| int i; |
| printf("uid= %d(%s) gid= %d(%s)", pw->pw_uid, pw->pw_name, |
| grp->gr_gid, grp->gr_name); |
| if (n) { |
| printf(" groups= "); |
| } |
| for (i = 0; i < n; i++) { |
| printf("%d(%s)%s", grps[i]->gr_gid, grps[i]->gr_name, |
| (i < n-1) ? ",": ""); |
| } |
| printf("\n"); |
| } |
| |
| void id_main(void) |
| { |
| int flags = toys.optflags; |
| |
| struct passwd *pw; |
| struct group *grp; |
| struct group **grps; |
| uid_t uid; |
| gid_t gid; |
| gid_t *groups; |
| int i; |
| int ngroups; |
| char *username; |
| |
| /* check if a username is given */ |
| if (*toys.optargs) { |
| username = *(toys.optargs); |
| pw = getpwnam(username); |
| if (!pw) { |
| printf("id: %s: no such user\n", username); |
| toys.exitval = 1; |
| return; |
| } |
| uid = pw->pw_uid; |
| gid = pw->pw_gid; |
| } else { |
| /* show effective, unless user specifies real */ |
| if (flags & FLAG_r) { |
| uid = getuid(); |
| gid = getgid(); |
| } else { |
| uid = geteuid(); |
| gid = getegid(); |
| } |
| } |
| |
| pw = getpwuid(uid); |
| if (!pw) { |
| perror("id"); |
| toys.exitval = 1; |
| return; |
| } |
| |
| grp = getgrgid(pw->pw_gid); |
| if (!grp) { |
| perror("id"); |
| toys.exitval = 1; |
| return; |
| } |
| |
| if (flags & FLAG_u) { |
| if (flags & FLAG_n) |
| printf("%s\n", pw->pw_name); |
| else |
| printf("%d\n", pw->pw_uid); |
| return; |
| } |
| if (flags & FLAG_g) { |
| if (flags & FLAG_n) |
| printf("%s\n", grp->gr_name); |
| else |
| printf("%d\n", grp->gr_gid); |
| return; |
| } |
| |
| |
| if (flags & FLAG_r) { |
| printf("-r can only be used in combination with -u or -g\n"); |
| toys.exitval = 1; |
| return; |
| } |
| ngroups = sysconf(_SC_NGROUPS_MAX); |
| /* fallback for number of groups to 32 */ |
| if (ngroups < 0) |
| ngroups = 32; |
| groups = malloc(ngroups * sizeof(gid_t)); |
| if (!groups) { |
| perror("id"); |
| toys.exitval = 1; |
| return; |
| } |
| if (getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups) < 0) { |
| perror("id"); |
| toys.exitval = 1; |
| return; |
| } |
| grps = malloc(ngroups * sizeof(struct group *)); |
| for (i = 0; i < ngroups; i++) { |
| struct group *tmp; |
| grps[i] = malloc(sizeof(struct group)); |
| size_t f = sysconf(_SC_GETGR_R_SIZE_MAX); |
| char *buf = malloc(f); |
| if (getgrgid_r(groups[i], grps[i], buf, f, &tmp) < 0) { |
| perror("id"); |
| continue; |
| } |
| if (tmp == NULL) { |
| perror("id"); |
| continue; |
| } |
| } |
| |
| if (flags & FLAG_G) { |
| for (i = 0; i < ngroups; i++) { |
| if (flags & FLAG_n) |
| printf("%s%s", !i ? "" : " ", grps[i]->gr_name); |
| else |
| printf("%s%d", !i ? "" : " ", grps[i]->gr_gid); |
| } |
| printf("\n"); |
| return; |
| } |
| |
| pretty_print(pw, grp, grps, ngroups); |
| for (i=0; i < ngroups; i++) |
| free(grps[i]); |
| |
| } |