commit 02e0a1de08e9f5a9ffff983c1f9ddce8bbd2ed7c
Author: sin <s...@2f30.org>
Date: Thu Feb 27 14:27:28 2014 +0000
Import id(1) from sbase
diff --git a/Makefile b/Makefile
index 63d4aae..dccfe4f 100644
--- a/Makefile
+++ b/Makefile
@@ -27,6 +27,7 @@ SRC = \
free.c \
getty.c \
halt.c \
+ id.c \
insmod.c \
lsmod.c \
lsusb.c \
diff --git a/id.1 b/id.1
new file mode 100644
index 0000000..967022c
--- /dev/null
+++ b/id.1
@@ -0,0 +1,18 @@
+.TH ID 1 sbase\-VERSION
+.SH NAME
+id \- print real and effective user and group IDs
+.SH SYNOPSIS
+.B id
+.RB [ -G ]
+.RB [ user | uid ]
+.SH DESCRIPTION
+Print user and group information of the calling process to standard output.
+If a login name or uid is specified, the user and group information of that
+user is displayed.
+.SH OPTIONS
+.TP
+.B \-G
+Display group information as whitespace separated numbers, in no particular
+order.
+.SH SEE ALSO
+.IR who(1)
diff --git a/id.c b/id.c
new file mode 100644
index 0000000..225c254
--- /dev/null
+++ b/id.c
@@ -0,0 +1,132 @@
+/* See LICENSE file for copyright and license details. */
+#include <sys/types.h>
+#include <errno.h>
+#include <unistd.h>
+#include <pwd.h>
+#include <grp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <ctype.h>
+#include "util.h"
+
+static void groupid(struct passwd *pw);
+static void user(struct passwd *pw);
+static void userid(uid_t id);
+static void usernam(const char *nam);
+
+static void
+usage(void)
+{
+ eprintf("usage: %s [-G] [user | uid]
", argv0);
+}
+
+static int Gflag = 0;
+
+int
+main(int argc, char *argv[])
+{
+ ARGBEGIN {
+ case 'G':
+ Gflag = 1;
+ break;
+ default:
+ usage();
+ } ARGEND;
+
+ errno = 0;
+ switch (argc) {
+ case 0:
+ userid(getuid());
+ break;
+ case 1:
+ /* user names can't begin [0-9] */
+ if (isdigit(argv[0][0]))
+ userid(estrtol(argv[0], 0));
+ else
+ usernam(argv[0]);
+ break;
+ default:
+ usage();
+ }
+
+ return EXIT_SUCCESS;
+}
+
+static void
+groupid(struct passwd *pw)
+{
+ gid_t gid, groups[NGROUPS_MAX];
+ int ngroups;
+ int i;
+
+ ngroups = NGROUPS_MAX;
+ getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
+ for (i = 0; i < ngroups; i++) {
+ gid = groups[i];
+ printf("%u", gid);
+ if (i < ngroups - 1)
+ putchar(' ');
+ }
+ putchar('
');
+}
+
+static void
+usernam(const char *nam)
+{
+ struct passwd *pw;
+
+ errno = 0;
+ pw = getpwnam(nam);
+ if (errno != 0)
+ eprintf("getpwnam %s:", nam);
+ else if (!pw)
+ eprintf("getpwnam %s: no such user
", nam);
+ if (Gflag)
+ groupid(pw);
+ else
+ user(pw);
+}
+
+static void
+userid(uid_t id)
+{
+ struct passwd *pw;
+
+ errno = 0;
+ pw = getpwuid(id);
+ if (errno != 0)
+ eprintf("getpwuid %d:", id);
+ else if (!pw)
+ eprintf("getpwuid %d: no such user
", id);
+ if (Gflag)
+ groupid(pw);
+ else
+ user(pw);
+}
+
+static void
+user(struct passwd *pw)
+{
+ struct group *gr;
+ gid_t gid, groups[NGROUPS_MAX];
+ int ngroups;
+ int i;
+
+ printf("uid=%u(%s)", pw->pw_uid, pw->pw_name);
+ printf(" gid=%u", pw->pw_gid);
+ if (!(gr = getgrgid(pw->pw_gid)))
+ eprintf("getgrgid:");
+ printf("(%s)", gr->gr_name);
+
+ ngroups = NGROUPS_MAX;
+ getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
+ for (i = 0; i < ngroups; i++) {
+ gid = groups[i];
+ printf("%s%u", !i ? " groups=" : ",", gid);
+ if (!(gr = getgrgid(gid)))
+ eprintf("getgrgid:");
+ printf("(%s)", gr->gr_name);
+ }
+ putchar('
');
+}
