lib/dpkg/progname.c

   1 /*
   2  * libdpkg - Debian packaging suite library routines
   3  * progname.c - program name handling functions
   4  *
   5  * Copyright © 2011 Guillem Jover <guillem@debian.org>
   6  *
   7  * This is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <config.h>
  22 #include <compat.h>
  23
  24 #ifdef HAVE_GETPROCS64
  25 #include <sys/types.h>
  26 #include <string.h>
  27 #include <unistd.h>
  28 #include <procinfo.h>
  29 #endif
  30 #include <errno.h>
  31 #include <stdlib.h>
  32
  33 #include <dpkg/path.h>
  34 #include <dpkg/progname.h>
  35
  36 static const char *progname;
  37
  38 /**
  39  * Set the program name.
  40  *
  41  * This function will set the program name which will be used by error
  42  * reporting functions, among others.
  43  *
  44  * @param name The new program name.
  45  */
  46 void
  47 dpkg_set_progname(const char *name)
  48 {
  49         progname = path_basename(name);
  50 }
  51
  52 #if defined(HAVE___PROGNAME)
  53 extern const char *__progname;
  54 #endif
  55
  56 /**
  57  * Get the program name.
  58  *
  59  * The program name might have been set previously by dpkg_set_progname(),
  60  * but if not this function will try to initialize it by system dependent
  61  * means, so it's half safe to not call dpkg_set_progname() at all. At worst
  62  * the function might return NULL in that case.
  63  *
  64  * @return A pointer to a static buffer with the program name.
  65  */
  66 const char *
  67 dpkg_get_progname(void)
  68 {
  69         if (progname == NULL) {
  70 #if defined(HAVE_PROGRAM_INVOCATION_SHORT_NAME)
  71                 progname = program_invocation_short_name;
  72 #elif defined(HAVE___PROGNAME)
  73                 progname = __progname;
  74 #elif defined(HAVE_GETPROGNAME)
  75                 progname = getprogname();
  76 #elif defined(HAVE_GETEXECNAME)
  77                 /* getexecname(3) returns an absolute path, normalize it. */
  78                 dpkg_set_progname(getexecname());
  79 #elif defined(HAVE_GETPROCS64)
  80                 struct progentry64 pe;
  81                 pid_t pid = getpid();
  82
  83                 if (getprocs64(&pe, sizeof(pe), NULL, 0, &pid, 1) >= 0)
  84                         progname = strdup(pe.pi_comm);
  85 #endif
  86         }
  87
  88         return progname;
  89 }