(Simple Advice): Clarify what job the example does.
[emacs.git] / lib-src / test-distrib.c
blob0333bd7d71057a0aaac2bf449ef1b001cfdcee9c
1 /* test-distrib.c --- testing distribution of nonprinting chars
3 Copyright (C) 1987, 1993, 1994, 1995, 1999, 2001
4 Free Software Foundation Inc.
6 This file is part of GNU Emacs.
8 GNU Emacs is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
11 any later version.
13 GNU Emacs is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GNU Emacs; see the file COPYING. If not, write to the
20 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
23 #ifdef HAVE_CONFIG_H
24 #include <config.h>
25 #endif
27 #include <stdio.h>
29 #ifdef HAVE_FCNTL_H
30 #include <fcntl.h>
31 #endif
33 #ifdef HAVE_UNISTD_H
34 #include <unistd.h>
35 #endif
37 #ifndef O_RDONLY
38 #define O_RDONLY 0
39 #endif
41 /* Break string in two parts to avoid buggy C compilers that ignore characters
42 after nulls in strings. */
44 char string1[] = "Testing distribution of nonprinting chars:\n\
45 Should be 0177: \177 Should be 0377: \377 Should be 0212: \212.\n\
46 Should be 0000: ";
48 char string2[] = ".\n\
49 This file is read by the `test-distribution' program.\n\
50 If you change it, you will make that program fail.\n";
52 char buf[300];
54 /* Like `read' but keeps trying until it gets SIZE bytes or reaches eof. */
55 int
56 cool_read (fd, buf, size)
57 int fd;
58 char *buf;
59 int size;
61 int num, sofar = 0;
63 while (1)
65 if ((num = read (fd, buf + sofar, size - sofar)) == 0)
66 return sofar;
67 else if (num < 0)
68 return num;
69 sofar += num;
73 int
74 main (argc, argv)
75 int argc;
76 char **argv;
78 int fd;
80 if (argc != 2)
82 fprintf (stderr, "Usage: %s testfile\n", argv[0]);
83 exit (EXIT_FAILURE);
85 fd = open (argv[1], O_RDONLY);
86 if (fd < 0)
88 perror (argv[1]);
89 exit (EXIT_FAILURE);
91 if (cool_read (fd, buf, sizeof string1) != sizeof string1 ||
92 strcmp (buf, string1) ||
93 cool_read (fd, buf, sizeof string2) != sizeof string2 - 1 ||
94 strncmp (buf, string2, sizeof string2 - 1))
96 fprintf (stderr, "Data in file `%s' has been damaged.\n\
97 Most likely this means that many nonprinting characters\n\
98 have been corrupted in the files of Emacs, and it will not work.\n",
99 argv[1]);
100 exit (EXIT_FAILURE);
102 close (fd);
103 return EXIT_SUCCESS;
106 /* arch-tag: 3a89005d-df98-4c32-aa9f-33570e16a26a
107 (do not change this comment) */
109 /* test-distrib.c ends here */