X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fprogname.c;h=0c195e521ad0aefe6ca1cf12b3a43c3e129b2050;hb=23eecb48e39afd0d267d64d40ba6bf97aa865e13;hp=47d08c65d5732517db1bf4315125d1a13d44b178;hpb=e5573b1bad88bfabcda181b9e0125fb0c52b7d3b;p=gnulib.git

diff --git a/lib/progname.c b/lib/progname.c
index 47d08c65d..0c195e521 100644
--- a/lib/progname.c
+++ b/lib/progname.c
@@ -1,6 +1,6 @@
 /* Program name management.
-   Copyright (C) 2001-2003, 2005-2007 Free Software Foundation, Inc.
-   Written by Bruno Haible <haible@clisp.cons.org>, 2001.
+   Copyright (C) 2001-2003, 2005-2013 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2001.
 
    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
@@ -22,6 +22,9 @@
 #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>
 
 
@@ -29,21 +32,61 @@
    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 && strncmp (base - 7, "/.libs/", 7) == 0)
-    argv0 = base;
-  if (strncmp (base, "lt-", 3) == 0)
-    argv0 = base + 3;
+    {
+      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
 }