1/* Program name management.
2 Copyright (C) 2001-2003, 2005-2019 Free Software Foundation, Inc.
3 Written by Bruno Haible <bruno@clisp.org>, 2001.
4
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18
19#include <config.h>
20
21/* Specification. */
22#undef ENABLE_RELOCATABLE /* avoid defining set_program_name as a macro */
23#include "progname.h"
24
25#include <errno.h> /* get program_invocation_name declaration */
26#include <stdio.h>
27#include <stdlib.h>
28#include <string.h>
29
30
31/* String containing name the program is called with.
32 To be initialized by main(). */
33const char *program_name = NULL;
34
35/* Set program_name, based on argv[0].
36 argv0 must be a string allocated with indefinite extent, and must not be
37 modified after this call. */
38void
39set_program_name (const char *argv0)
40{
41 /* libtool creates a temporary executable whose name is sometimes prefixed
42 with "lt-" (depends on the platform). It also makes argv[0] absolute.
43 But the name of the temporary executable is a detail that should not be
44 visible to the end user and to the test suite.
45 Remove this "<dirname>/.libs/" or "<dirname>/.libs/lt-" prefix here. */
46 const char *slash;
47 const char *base;
48
49 /* Sanity check. POSIX requires the invoking process to pass a non-NULL
50 argv[0]. */
51 if (argv0 == NULL)
52 {
53 /* It's a bug in the invoking program. Help diagnosing it. */
54 fputs ("A NULL argv[0] was passed through an exec system call.\n",
55 stderr);
56 abort ();
57 }
58
59 slash = strrchr (argv0, '/');
60 base = (slash != NULL ? slash + 1 : argv0);
61 if (base - argv0 >= 7 && strncmp (base - 7, "/.libs/", 7) == 0)
62 {
63 argv0 = base;
64 if (strncmp (base, "lt-", 3) == 0)
65 {
66 argv0 = base + 3;
67 /* On glibc systems, remove the "lt-" prefix from the variable
68 program_invocation_short_name. */
69#if HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME
70 program_invocation_short_name = (char *) argv0;
71#endif
72 }
73 }
74
75 /* But don't strip off a leading <dirname>/ in general, because when the user
76 runs
77 /some/hidden/place/bin/cp foo foo
78 he should get the error message
79 /some/hidden/place/bin/cp: `foo' and `foo' are the same file
80 not
81 cp: `foo' and `foo' are the same file
82 */
83
84 program_name = argv0;
85
86 /* On glibc systems, the error() function comes from libc and uses the
87 variable program_invocation_name, not program_name. So set this variable
88 as well. */
89#if HAVE_DECL_PROGRAM_INVOCATION_NAME
90 program_invocation_name = (char *) argv0;
91#endif
92}
93