usr/src/usr.bin/id/id.c

/*-
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1991 The Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)id.c        5.1 (Berkeley) %G%";
#endif /* not lint */

#include <sys/param.h>
#include <pwd.h>
#include <grp.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

typedef struct passwd PW;
typedef struct group GR;

void    current __P((void));
void    err __P((const char *, ...));
int     gcmp __P((const void *, const void *));
void    sgroup __P((PW *));
void    ugroup __P((PW *));
void    usage __P((void));
void    user __P((PW *));
PW     *who __P((char *));

int Gflag, gflag, nflag, rflag, uflag;

main(argc, argv)
        int argc;
        char *argv[];
{
        GR *gr;
        PW *pw;
        int ch, id;

        while ((ch = getopt(argc, argv, "Ggnru")) != EOF)
                switch(ch) {
                case 'G':
                        Gflag = 1;
                        break;
                case 'g':
                        gflag = 1;
                        break;
                case 'n':
                        nflag = 1;
                        break;
                case 'r':
                        rflag = 1;
                        break;
                case 'u':
                        uflag = 1;
                        break;
                case '?':
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        pw = *argv ? who(*argv) : NULL;

        if (Gflag + gflag + uflag > 1)
                usage();

        if (Gflag) {
                if (nflag)
                        sgroup(pw);
                else
                        ugroup(pw);
                exit(0);
        }

        if (gflag) {
                id = pw ? pw->pw_gid : rflag ? getgid() : getegid();
                if (nflag && (gr = getgrgid(id))) {
                        (void)printf("%s\n", gr->gr_name);
                        exit(0);
                }
                (void)printf("%u\n", id);
                exit(0);
        }

        if (uflag) {
                id = pw ? pw->pw_uid : rflag ? getuid() : geteuid();
                if (nflag && (pw = getpwuid(id))) {
                        (void)printf("%s\n", pw->pw_name);
                        exit(0);
                }
                (void)printf("%u\n", id);
                exit(0);
        }

        if (pw)
                user(pw);
        else
                current();
        exit(0);
}

void
sgroup(pw)
        PW *pw;
{
        register int id, lastid;
        char *fmt;

        if (pw) {
                register GR *gr;
                register char *name, **p;

                name = pw->pw_name;
                for (fmt = "%s", lastid = -1; gr = getgrent(); lastid = id) {
                        for (p = gr->gr_mem; p && *p; p++)
                                if (!strcmp(*p, name)) {
                                        (void)printf(fmt, gr->gr_name);
                                        fmt = " %s";
                                        break;
                                }
                }
        } else {
                GR *gr;
                register int ngroups;
                int groups[NGROUPS + 1];

                groups[0] = getgid();
                ngroups = getgroups(NGROUPS, groups + 1) + 1;
                heapsort(groups, ngroups, sizeof(groups[0]), gcmp);
                for (fmt = "%s", lastid = -1; --ngroups >= 0;) {
                        if (lastid == (id = groups[ngroups]))
                                continue;
                        if (gr = getgrgid(id))
                                (void)printf(fmt, gr->gr_name);
                        else
                                (void)printf(*fmt == ' ' ? " %u" : "%u", id);
                        fmt = " %s";
                        lastid = id;
                }
        }
        (void)printf("\n");
}

void
ugroup(pw)
        PW *pw;
{
        register int id, lastid;
        register char *fmt;

        if (pw) {
                register GR *gr;
                register char *name, **p;

                name = pw->pw_name;
                for (fmt = "%u", lastid = -1; gr = getgrent(); lastid = id) {
                        for (p = gr->gr_mem; p && *p; p++)
                                if (!strcmp(*p, name)) {
                                        (void)printf(fmt, gr->gr_gid);
                                        fmt = " %u";
                                        break;
                                }
                }
        } else {
                register int ngroups;
                int groups[NGROUPS + 1];

                groups[0] = getgid();
                ngroups = getgroups(NGROUPS, groups + 1) + 1;
                heapsort(groups, ngroups, sizeof(groups[0]), gcmp);
                for (fmt = "%u", lastid = -1; --ngroups >= 0;) {
                        if (lastid == (id = groups[ngroups]))
                                continue;
                        (void)printf(fmt, id);
                        fmt = " %u";
                        lastid = id;
                }
        }
        (void)printf("\n");
}

void
current()
{
        GR *gr;
        PW *pw;
        int id, eid, lastid, ngroups, groups[NGROUPS];
        char *fmt;

        id = getuid();
        (void)printf("uid=%u", id);
        if (pw = getpwuid(id))
                (void)printf("(%s)", pw->pw_name);
        if ((eid = geteuid()) != id) {
                (void)printf(" euid=%u", eid);
                if (pw = getpwuid(eid))
                        (void)printf("(%s)", pw->pw_name);
        }
        id = getgid();
        (void)printf(" gid=%u", id);
        if (gr = getgrgid(id))
                (void)printf("(%s)", gr->gr_name);
        if ((eid = getegid()) != id) {
                (void)printf(" egid=%u", eid);
                if (gr = getgrgid(eid))
                        (void)printf("(%s)", gr->gr_name);
        }
        if (ngroups = getgroups(NGROUPS, groups)) {
                heapsort(groups, ngroups, sizeof(groups[0]), gcmp);
                for (fmt = " groups=%u", lastid = -1; --ngroups >= 0;
                    fmt = ", %u", lastid = id) {
                        id = groups[ngroups];
                        if (lastid == id)
                                continue;
                        (void)printf(fmt, id);
                        if (gr = getgrgid(id))
                                (void)printf("(%s)", gr->gr_name);
                }
        }
        (void)printf("\n");
}

void
user(pw)
        register PW *pw;
{
        register GR *gr;
        register int id, lastid;
        register char *fmt, **p;

        id = pw->pw_uid;
        (void)printf("uid=%u(%s)", id, pw->pw_name);
        (void)printf(" gid=%u", pw->pw_gid);
        if (gr = getgrgid(id))
                (void)printf("(%s)", gr->gr_name);
        for (fmt = " groups=%u(%s)", lastid = -1; gr = getgrent();
            lastid = id) {
                if (pw->pw_gid == gr->gr_gid)
                        continue;
                for (p = gr->gr_mem; p && *p; p++)
                        if (!strcmp(*p, pw->pw_name)) {
                                (void)printf(fmt, gr->gr_gid, gr->gr_name);
                                fmt = ", %u(%s)";
                                break;
                        }
        }
        (void)printf("\n");
}

PW *
who(u)
        char *u;
{
        PW *pw;
        long id;
        char *ep;

        /*
         * Translate user argument into a pw pointer.  First, try to
         * get it as specified.  If that fails, try it as a number.
         */
        if (pw = getpwnam(u))
                return(pw);
        id = strtol(u, &ep, 10);
        if (*u && !*ep && (pw = getpwuid(id)))
                return(pw);
        err("%s: No such user", u);
        /* NOTREACHED */
}

gcmp(a, b)
        const void *a, *b;
{
        return(*(int *)b - *(int *)a);
}

#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif

void
#if __STDC__
err(const char *fmt, ...)
#else
err(fmt, va_alist)
        char *fmt;
        va_dcl
#endif
{
        va_list ap;
#if __STDC__
        va_start(ap, fmt);
#else
        va_start(ap);
#endif
        (void)fprintf(stderr, "id: ");
        (void)vfprintf(stderr, fmt, ap);
        va_end(ap);
        (void)fprintf(stderr, "\n");
        exit(1);
        /* NOTREACHED */
}

void
usage()
{
        (void)fprintf(stderr, "usage: id [user]\n");
        (void)fprintf(stderr, "       id -G [-n] [user]\n");
        (void)fprintf(stderr, "       id -g [-nr] [user]\n");
        (void)fprintf(stderr, "       id -u [-nr] [user]\n");
        exit(1);
}