src/coreutils.c

   1 /* Copyright (C) 2014-2023 Free Software Foundation, Inc.
   2
   3    This program is free software: you can redistribute it and/or modify
   4    it under the terms of the GNU General Public License as published by
   5    the Free Software Foundation, either version 3 of the License, or
   6    (at your option) any later version.
   7
   8    This program is distributed in the hope that it will be useful,
   9    but WITHOUT ANY WARRANTY; without even the implied warranty of
  10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11    GNU General Public License for more details.
  12
  13    You should have received a copy of the GNU General Public License
  14    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  15
  16 /* coreutils.c aggregates the functionality of every other tool into a single
  17    binary multiplexed by the value of argv[0]. This is enabled by passing
  18    --enable-single-binary to configure.
  19
  20    Written by Alex Deymo <deymo@chromium.org>.  */
  21
  22 #include <config.h>
  23 #include <getopt.h>
  24 #include <stdio.h>
  25 #if HAVE_PRCTL
  26 # include <sys/prctl.h>
  27 #endif
  28
  29 #include "system.h"
  30 #include "die.h"
  31 #include "error.h"
  32 #include "quote.h"
  33
  34 #ifdef SINGLE_BINARY
  35 /* Declare the main function on each one of the selected tools.  This name
  36    needs to match the one passed as CFLAGS on single-binary.mk (generated
  37    by gen-single-binary.sh). */
  38 # define SINGLE_BINARY_PROGRAM(prog_name_str, main_name) \
  39   int single_binary_main_##main_name (int, char **);
  40 # include "coreutils.h"
  41 # undef SINGLE_BINARY_PROGRAM
  42 #endif
  43
  44 /* The official name of this program (e.g., no 'g' prefix).  */
  45 #define PROGRAM_NAME "coreutils"
  46
  47 #define AUTHORS \
  48   proper_name ("Alex Deymo")
  49
  50 static struct option const long_options[] =
  51 {
  52   {GETOPT_HELP_OPTION_DECL},
  53   {GETOPT_VERSION_OPTION_DECL},
  54   {NULL, 0, NULL, 0}
  55 };
  56
  57
  58 void
  59 usage (int status)
  60 {
  61   if (status != EXIT_SUCCESS)
  62     emit_try_help ();
  63   else
  64     {
  65       printf (_("\
  66 Usage: %s --coreutils-prog=PROGRAM_NAME [PARAMETERS]... \n"),
  67               program_name);
  68       fputs (_("\
  69 Execute the PROGRAM_NAME built-in program with the given PARAMETERS.\n\
  70 \n"), stdout);
  71       fputs (HELP_OPTION_DESCRIPTION, stdout);
  72       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  73
  74 #ifdef SINGLE_BINARY
  75 /* XXX: Ideally we'd like to present "install" here, not "ginstall".  */
  76       char const *prog_name_list =
  77 # define SINGLE_BINARY_PROGRAM(prog_name_str, main_name) " " prog_name_str
  78 # include "coreutils.h"
  79 # undef SINGLE_BINARY_PROGRAM
  80       ;
  81       printf ("\n\
  82 Built-in programs:\n\
  83 %s\n", prog_name_list);
  84 #endif
  85
  86       printf (_("\
  87 \n\
  88 Use: '%s --coreutils-prog=PROGRAM_NAME --help' for individual program help.\n"),
  89               program_name);
  90       emit_ancillary_info (PROGRAM_NAME);
  91     }
  92   exit (status);
  93 }
  94
  95 static void
  96 launch_program (char const *prog_name, int prog_argc, char **prog_argv)
  97 {
  98   int (*prog_main) (int, char **) = NULL;
  99
 100   /* Ensure that at least one parameter was passed.  */
 101   if (!prog_argc || !prog_argv || !prog_argv[0] || !prog_name)
 102     return;
 103
 104 #ifdef SINGLE_BINARY
 105   if (false);
 106   /* Look up the right main program.  */
 107 # define SINGLE_BINARY_PROGRAM(prog_name_str, main_name) \
 108   else if (STREQ (prog_name_str, prog_name)) \
 109     prog_main = single_binary_main_##main_name;
 110 # include "coreutils.h"
 111 # undef SINGLE_BINARY_PROGRAM
 112 #endif
 113
 114   if (! prog_main)
 115     return;
 116
 117 #if HAVE_PRCTL && defined PR_SET_NAME
 118   /* Not being able to set the program name is not a fatal error.  */
 119   prctl (PR_SET_NAME, prog_argv[0]);
 120 #endif
 121 #if HAVE_PRCTL && defined PR_SET_MM_ARG_START
 122   /* Shift the beginning of the command line to prog_argv[0] (if set) so
 123      /proc/$pid/cmdline reflects a more specific value.  Note one needs
 124      CAP_SYS_RESOURCE or root privileges for this to succeed.  */
 125   prctl (PR_SET_MM, PR_SET_MM_ARG_START, prog_argv[0], 0, 0);
 126 #endif
 127
 128   exit (prog_main (prog_argc, prog_argv));
 129 }
 130
 131 int
 132 main (int argc, char **argv)
 133 {
 134   char *prog_name = last_component (argv[0]);
 135   int optc;
 136
 137   /* Map external name to internal name.  */
 138   char ginstall[] = "ginstall";
 139   if (STREQ (prog_name, "install"))
 140     prog_name = ginstall;
 141
 142   /* If this program is called directly as "coreutils" or if the value of
 143      argv[0] is an unknown tool (which "coreutils" is), we proceed and parse
 144      the options.  */
 145   launch_program (prog_name, argc, argv);
 146
 147   /* No known program was selected via argv[0].  Try parsing the first
 148      argument as --coreutils-prog=PROGRAM to determine the program.  The
 149      invocation for this case should be:
 150        path/to/coreutils --coreutils-prog=someprog someprog ...
 151      The third argument is what the program will see as argv[0].  */
 152
 153   if (argc >= 2)
 154     {
 155       size_t nskip = 0;
 156       char *arg_name = NULL;
 157
 158       /* If calling coreutils directly, the "script" name isn't passed.
 159          Distinguish the two cases with a -shebang suffix.  */
 160       if (STRPREFIX (argv[1], "--coreutils-prog="))
 161         {
 162           nskip = 1;
 163           arg_name = prog_name = argv[1] + strlen ("--coreutils-prog=");
 164         }
 165       else if (STRPREFIX (argv[1], "--coreutils-prog-shebang="))
 166         {
 167           nskip = 2;
 168           prog_name = argv[1] + strlen ("--coreutils-prog-shebang=");
 169           if (argc >= 3)
 170             arg_name = last_component (argv[2]);
 171           else
 172             arg_name = prog_name;
 173         }
 174
 175       if (nskip)
 176         {
 177           argv[nskip] = arg_name; /* XXX: Discards any specified path.  */
 178           launch_program (prog_name, argc - nskip, argv + nskip);
 179           die (EXIT_FAILURE, 0, _("unknown program %s"),
 180                quote (prog_name));
 181         }
 182     }
 183
 184   /* No known program was selected.  From here on, we behave like any other
 185      coreutils program.  */
 186   initialize_main (&argc, &argv);
 187   set_program_name (argv[0]);
 188   setlocale (LC_ALL, "");
 189   bindtextdomain (PACKAGE, LOCALEDIR);
 190   textdomain (PACKAGE);
 191   atexit (close_stdout);
 192
 193   if ((optc = getopt_long (argc, argv, "", long_options, NULL)) != -1)
 194     switch (optc)
 195       {
 196       case_GETOPT_HELP_CHAR;
 197
 198       case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 199       }
 200
 201   /* Only print the error message when no options have been passed
 202      to coreutils.  */
 203   if (optind == 1 && prog_name && !STREQ (prog_name, "coreutils"))
 204     error (0, 0, _("unknown program %s"),
 205            quote (prog_name));
 206
 207   usage (EXIT_FAILURE);
 208 }