bc: convert to "G trick" - this returns bc to zero bss increase
[oweals/busybox.git] / coreutils / who.c
index 9f37f65fdf54a3ecc51f859427d769538789d06c..80226c3d6a74b8a035a28c9e967cf40ec35bfe43 100644 (file)
@@ -1,5 +1,5 @@
 /* vi: set sw=4 ts=4: */
-/*----------------------------------------------------------------------
+/*
  * Mini who is used to display user name, login time,
  * idle time and host name.
  *
  * Copyright (c) 2002 AYR Networks, Inc.
  *
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
- *
- *----------------------------------------------------------------------
  */
+//config:config WHO
+//config:      bool "who (3.7 kb)"
+//config:      default y
+//config:      depends on FEATURE_UTMP
+//config:      help
+//config:      Print users currently logged on.
+//config:
+// procps-ng has this variation of "who":
+//config:config W
+//config:      bool "w (3.7 kb)"
+//config:      default y
+//config:      depends on FEATURE_UTMP
+//config:      help
+//config:      Print users currently logged on.
+//config:
+//config:config USERS
+//config:      bool "users (3.2 kb)"
+//config:      default y
+//config:      depends on FEATURE_UTMP
+//config:      help
+//config:      Print users currently logged on.
+
+//                APPLET_NOEXEC:name   main location        suid_type     help
+//applet:IF_USERS(APPLET_NOEXEC(users, who, BB_DIR_USR_BIN, BB_SUID_DROP, users))
+//applet:IF_W(    APPLET_NOEXEC(w,     who, BB_DIR_USR_BIN, BB_SUID_DROP, w))
+//applet:IF_WHO(  APPLET_NOEXEC(who,   who, BB_DIR_USR_BIN, BB_SUID_DROP, who))
+
+//kbuild:lib-$(CONFIG_USERS) += who.o
+//kbuild:lib-$(CONFIG_W)     += who.o
+//kbuild:lib-$(CONFIG_WHO)   += who.o
+
 /* BB_AUDIT SUSv3 _NOT_ compliant -- missing options -b, -d, -l, -m, -p, -q, -r, -s, -t, -T, -u; Missing argument 'file'.  */
 
+//usage:#define users_trivial_usage
+//usage:       ""
+//usage:#define users_full_usage "\n\n"
+//usage:       "Print the users currently logged on"
+
+//usage:#define w_trivial_usage
+//usage:       ""
+//usage:#define w_full_usage "\n\n"
+//usage:       "Show who is logged on"
+//
+// procps-ng 3.3.10:
+//           "\n       -h, --no-header"
+//           "\n       -u, --no-current"
+//     Ignores the username while figuring out the current process
+//     and cpu times.  To demonstrate this, do a "su" and do a "w" and a "w -u".
+//           "\n       -s, --short"
+//     Short format.  Don't print the login time, JCPU or PCPU times.
+//           "\n       -f, --from"
+//     Toggle printing the from (remote hostname) field.
+//     The default is for the from field to not be printed
+//           "\n       -i, --ip-addr"
+//     Display IP address instead of hostname for from field.
+//           "\n       -o, --old-style"
+//     Old style output. Prints blank space for idle times less than one minute.
+// Example output:
+//  17:28:00 up 4 days, 22:41,  4 users,  load average: 0.84, 0.97, 0.90
+// USER     TTY        LOGIN@   IDLE   JCPU   PCPU WHAT
+// root     tty1      Thu18    4days  4:33m  0.07s /bin/sh /etc/xdg/xfce4/xinitrc -- vt
+// root     pts/1     Mon13    3:24m  1:01   0.01s w
+
 //usage:#define who_trivial_usage
 //usage:       "[-a]"
 //usage:#define who_full_usage "\n\n"
 //usage:       "Show who is logged on\n"
 //usage:     "\n       -a      Show all"
+//usage:     "\n       -H      Print column headers"
 
 #include "libbb.h"
 
@@ -47,50 +107,64 @@ static void idle_string(char *str6, time_t t)
 int who_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int who_main(int argc UNUSED_PARAM, char **argv)
 {
-       struct utmp *ut;
+#define CNT_APPLET (ENABLE_USERS + ENABLE_W + ENABLE_WHO)
+       int do_users = (ENABLE_USERS && (CNT_APPLET == 1 || applet_name[0] == 'u'));
+       int do_w     = (ENABLE_W     && (CNT_APPLET == 1 || applet_name[1] == '\0'));
+       int do_who   = (ENABLE_WHO   && (CNT_APPLET == 1 || applet_name[1] == 'h'));
+       struct utmpx *ut;
        unsigned opt;
+       const char *fmt = "%s";
 
-       opt_complementary = "=0";
-       opt = getopt32(argv, "aH");
-       if (opt & 2) // -H
-               printf("USER\t\tTTY\t\tIDLE\tTIME\t\t HOST\n");
+       opt = getopt32(argv, do_who ? "^" "aH" "\0" "=0": "^" "" "\0" "=0");
+       if ((opt & 2) || do_w) /* -H or we are w */
+               puts("USER\t\tTTY\t\tIDLE\tTIME\t\t HOST");
 
-       setutent();
-       while ((ut = getutent()) != NULL) {
+       setutxent();
+       while ((ut = getutxent()) != NULL) {
                if (ut->ut_user[0]
                 && ((opt & 1) || ut->ut_type == USER_PROCESS)
                ) {
-                       char str6[6];
-                       char name[sizeof("/dev/") + sizeof(ut->ut_line) + 1];
-                       struct stat st;
-                       time_t seconds;
+                       if (!do_users) {
+                               char str6[6];
+                               char name[sizeof("/dev/") + sizeof(ut->ut_line) + 1];
+                               struct stat st;
+                               time_t seconds;
 
-                       str6[0] = '?';
-                       str6[1] = '\0';
-                       strcpy(name, "/dev/");
-                       safe_strncpy(ut->ut_line[0] == '/' ? name : name + sizeof("/dev/")-1,
-                               ut->ut_line,
-                               sizeof(ut->ut_line)+1
-                       );
-                       if (stat(name, &st) == 0)
-                               idle_string(str6, st.st_atime);
-                       /* manpages say ut_tv.tv_sec *is* time_t,
-                        * but some systems have it wrong */
-                       seconds = ut->ut_tv.tv_sec;
-                       /* How wide time field can be?
-                        * "Nov 10 19:33:20": 15 chars
-                        * "2010-11-10 19:33": 16 chars
-                        */
-                       printf("%-15.*s %-15.*s %-7s %-16.16s %.*s\n",
-                                       (int)sizeof(ut->ut_user), ut->ut_user,
-                                       (int)sizeof(ut->ut_line), ut->ut_line,
-                                       str6,
-                                       ctime(&seconds) + 4,
-                                       (int)sizeof(ut->ut_host), ut->ut_host
-                       );
+                               str6[0] = '?';
+                               str6[1] = '\0';
+                               strcpy(name, "/dev/");
+                               safe_strncpy(ut->ut_line[0] == '/' ? name : name + sizeof("/dev/")-1,
+                                       ut->ut_line,
+                                       sizeof(ut->ut_line)+1
+                               );
+                               if (stat(name, &st) == 0)
+                                       idle_string(str6, st.st_atime);
+                               /* manpages say ut_tv.tv_sec *is* time_t,
+                                * but some systems have it wrong */
+                               seconds = ut->ut_tv.tv_sec;
+                               /* How wide time field can be?
+                                * "Nov 10 19:33:20": 15 chars
+                                * "2010-11-10 19:33": 16 chars
+                                */
+                               printf("%-15.*s %-15.*s %-7s %-16.16s %.*s\n",
+                                               (int)sizeof(ut->ut_user), ut->ut_user,
+                                               (int)sizeof(ut->ut_line), ut->ut_line,
+                                               str6,
+// TODO: with LANG=en_US.UTF-8, who from coreutils 8.25 shows
+// TIME col as "2017-04-06 18:47" (the default format is "Apr  6 18:47").
+// The former format looks saner to me. Switch to it unconditionally?
+                                               ctime(&seconds) + 4,
+                                               (int)sizeof(ut->ut_host), ut->ut_host
+                               );
+                       } else {
+                               printf(fmt, ut->ut_user);
+                               fmt = " %s";
+                       }
                }
        }
+       if (do_users)
+               bb_putchar('\n');
        if (ENABLE_FEATURE_CLEAN_UP)
-               endutent();
+               endutxent();
        return EXIT_SUCCESS;
 }