maint: update copyright

[gnulib.git] / lib / progname.c

diff --git a/lib/progname.c b/lib/progname.c
index d3dc8cf..2919be9 100644 (file)
--- a/lib/progname.c
+++ b/lib/progname.c
@@ -1,11 +1,11 @@
 /* Program name management.
-   Copyright (C) 2001-2003, 2005-2006 Free Software Foundation, Inc.
-   Written by Bruno Haible <haible@clisp.cons.org>, 2001.
+   Copyright (C) 2001-2003, 2005-2014 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2001.
 
-   This program is free software; you can redistribute it and/or modify
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -13,39 +13,80 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software Foundation,
-   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 
 #include <config.h>
 
 /* Specification.  */
+#undef ENABLE_RELOCATABLE /* avoid defining set_program_name as a macro */
 #include "progname.h"
 
+#include <errno.h> /* get program_invocation_name declaration */
+#include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
-#undef set_program_name
-
 
 /* String containing name the program is called with.
    To be initialized by main().  */
 const char *program_name = NULL;
 
-/* Set program_name, based on argv[0].  */
+/* Set program_name, based on argv[0].
+   argv0 must be a string allocated with indefinite extent, and must not be
+   modified after this call.  */
 void
 set_program_name (const char *argv0)
 {
   /* libtool creates a temporary executable whose name is sometimes prefixed
      with "lt-" (depends on the platform).  It also makes argv[0] absolute.
+     But the name of the temporary executable is a detail that should not be
+     visible to the end user and to the test suite.
      Remove this "<dirname>/.libs/" or "<dirname>/.libs/lt-" prefix here.  */
   const char *slash;
   const char *base;
 
+  /* Sanity check.  POSIX requires the invoking process to pass a non-NULL
+     argv[0].  */
+  if (argv0 == NULL)
+    {
+      /* It's a bug in the invoking program.  Help diagnosing it.  */
+      fputs ("A NULL argv[0] was passed through an exec system call.\n",
+             stderr);
+      abort ();
+    }
+
   slash = strrchr (argv0, '/');
   base = (slash != NULL ? slash + 1 : argv0);
-  if (base - argv0 >= 7 && memcmp (base - 7, "/.libs/", 7) == 0)
-    argv0 = base;
-  if (strncmp (base, "lt-", 3) == 0)
-    argv0 = base + 3;
+  if (base - argv0 >= 7 && strncmp (base - 7, "/.libs/", 7) == 0)
+    {
+      argv0 = base;
+      if (strncmp (base, "lt-", 3) == 0)
+        {
+          argv0 = base + 3;
+          /* On glibc systems, remove the "lt-" prefix from the variable
+             program_invocation_short_name.  */
+#if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME
+          program_invocation_short_name = (char *) argv0;
+#endif
+        }
+    }
+
+  /* But don't strip off a leading <dirname>/ in general, because when the user
+     runs
+         /some/hidden/place/bin/cp foo foo
+     he should get the error message
+         /some/hidden/place/bin/cp: `foo' and `foo' are the same file
+     not
+         cp: `foo' and `foo' are the same file
+   */
+
   program_name = argv0;
+
+  /* On glibc systems, the error() function comes from libc and uses the
+     variable program_invocation_name, not program_name.  So set this variable
+     as well.  */
+#if HAVE_DECL_PROGRAM_INVOCATION_NAME
+  program_invocation_name = (char *) argv0;
+#endif
 }