freebsd-dev/contrib/texinfo/info/filesys.c
2002-03-25 13:08:32 +00:00

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/* filesys.c -- filesystem specific functions.
$Id: filesys.c,v 1.14 2002/03/02 15:05:04 karl Exp $
Copyright (C) 1993, 97, 98, 2000 Free Software Foundation, Inc.
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.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
Written by Brian Fox (bfox@ai.mit.edu). */
#include "info.h"
#include "tilde.h"
#include "filesys.h"
/* Local to this file. */
static char *info_file_in_path (), *lookup_info_filename ();
static char *info_absolute_file ();
static void remember_info_filename (), maybe_initialize_infopath ();
typedef struct
{
char *suffix;
char *decompressor;
} COMPRESSION_ALIST;
static char *info_suffixes[] = {
".info",
"-info",
"/index",
".inf", /* 8+3 file on filesystem which supports long file names */
#ifdef __MSDOS__
/* 8+3 file names strike again... */
".in", /* for .inz, .igz etc. */
".i",
#endif
"",
NULL
};
static COMPRESSION_ALIST compress_suffixes[] = {
{ ".gz", "gunzip" },
{ ".bz2", "bunzip2" },
{ ".z", "gunzip" },
{ ".Z", "uncompress" },
{ ".Y", "unyabba" },
#ifdef __MSDOS__
{ "gz", "gunzip" },
{ "z", "gunzip" },
#endif
{ (char *)NULL, (char *)NULL }
};
/* The path on which we look for info files. You can initialize this
from the environment variable INFOPATH if there is one, or you can
call info_add_path () to add paths to the beginning or end of it.
You can call zap_infopath () to make the path go away. */
char *infopath = (char *)NULL;
static int infopath_size = 0;
/* Expand the filename in PARTIAL to make a real name for this operating
system. This looks in INFO_PATHS in order to find the correct file.
If it can't find the file, it returns NULL. */
static char *local_temp_filename = (char *)NULL;
static int local_temp_filename_size = 0;
char *
info_find_fullpath (partial)
char *partial;
{
int initial_character;
char *temp;
filesys_error_number = 0;
maybe_initialize_infopath ();
if (partial && (initial_character = *partial))
{
char *expansion;
expansion = lookup_info_filename (partial);
if (expansion)
return (expansion);
/* If we have the full path to this file, we still may have to add
various extensions to it. I guess we have to stat this file
after all. */
if (IS_ABSOLUTE (partial))
temp = info_absolute_file (partial);
else if (initial_character == '~')
{
expansion = tilde_expand_word (partial);
if (IS_ABSOLUTE (expansion))
{
temp = info_absolute_file (expansion);
free (expansion);
}
else
temp = expansion;
}
else if (initial_character == '.' &&
(IS_SLASH (partial[1]) ||
(partial[1] == '.' && IS_SLASH (partial[2]))))
{
if (local_temp_filename_size < 1024)
local_temp_filename = (char *)xrealloc
(local_temp_filename, (local_temp_filename_size = 1024));
#if defined (HAVE_GETCWD)
if (!getcwd (local_temp_filename, local_temp_filename_size))
#else /* !HAVE_GETCWD */
if (!getwd (local_temp_filename))
#endif /* !HAVE_GETCWD */
{
filesys_error_number = errno;
return (partial);
}
strcat (local_temp_filename, "/");
strcat (local_temp_filename, partial);
temp = info_absolute_file (local_temp_filename); /* try extensions */
if (!temp)
partial = local_temp_filename;
}
else
temp = info_file_in_path (partial, infopath);
if (temp)
{
remember_info_filename (partial, temp);
if (strlen (temp) > local_temp_filename_size)
local_temp_filename = (char *) xrealloc
(local_temp_filename,
(local_temp_filename_size = (50 + strlen (temp))));
strcpy (local_temp_filename, temp);
free (temp);
return (local_temp_filename);
}
}
return (partial);
}
/* Scan the list of directories in PATH looking for FILENAME. If we find
one that is a regular file, return it as a new string. Otherwise, return
a NULL pointer. */
static char *
info_file_in_path (filename, path)
char *filename, *path;
{
struct stat finfo;
char *temp_dirname;
int statable, dirname_index;
/* Reject ridiculous cases up front, to prevent infinite recursion
later on. E.g., someone might say "info '(.)foo'"... */
if (!*filename || STREQ (filename, ".") || STREQ (filename, ".."))
return NULL;
dirname_index = 0;
while ((temp_dirname = extract_colon_unit (path, &dirname_index)))
{
register int i, pre_suffix_length;
char *temp;
/* Expand a leading tilde if one is present. */
if (*temp_dirname == '~')
{
char *expanded_dirname;
expanded_dirname = tilde_expand_word (temp_dirname);
free (temp_dirname);
temp_dirname = expanded_dirname;
}
temp = (char *)xmalloc (30 + strlen (temp_dirname) + strlen (filename));
strcpy (temp, temp_dirname);
if (!IS_SLASH (temp[(strlen (temp)) - 1]))
strcat (temp, "/");
strcat (temp, filename);
pre_suffix_length = strlen (temp);
free (temp_dirname);
for (i = 0; info_suffixes[i]; i++)
{
strcpy (temp + pre_suffix_length, info_suffixes[i]);
statable = (stat (temp, &finfo) == 0);
/* If we have found a regular file, then use that. Else, if we
have found a directory, look in that directory for this file. */
if (statable)
{
if (S_ISREG (finfo.st_mode))
{
return (temp);
}
else if (S_ISDIR (finfo.st_mode))
{
char *newpath, *filename_only, *newtemp;
newpath = xstrdup (temp);
filename_only = filename_non_directory (filename);
newtemp = info_file_in_path (filename_only, newpath);
free (newpath);
if (newtemp)
{
free (temp);
return (newtemp);
}
}
}
else
{
/* Add various compression suffixes to the name to see if
the file is present in compressed format. */
register int j, pre_compress_suffix_length;
pre_compress_suffix_length = strlen (temp);
for (j = 0; compress_suffixes[j].suffix; j++)
{
strcpy (temp + pre_compress_suffix_length,
compress_suffixes[j].suffix);
statable = (stat (temp, &finfo) == 0);
if (statable && (S_ISREG (finfo.st_mode)))
return (temp);
}
}
}
free (temp);
}
return ((char *)NULL);
}
/* Assume FNAME is an absolute file name, and check whether it is
a regular file. If it is, return it as a new string; otherwise
return a NULL pointer. We do it by taking the file name apart
into its directory and basename parts, and calling info_file_in_path.*/
static char *
info_absolute_file (fname)
char *fname;
{
char *containing_dir = xstrdup (fname);
char *base = filename_non_directory (containing_dir);
if (base > containing_dir)
base[-1] = '\0';
return info_file_in_path (filename_non_directory (fname), containing_dir);
}
/* Given a string containing units of information separated by
the PATH_SEP character, return the next one pointed to by
IDX, or NULL if there are no more.
Advance IDX to the character after the colon. */
char *
extract_colon_unit (string, idx)
char *string;
int *idx;
{
register int i, start;
i = start = *idx;
if ((i >= strlen (string)) || !string)
return ((char *) NULL);
while (string[i] && string[i] != PATH_SEP[0])
i++;
if (i == start)
{
return ((char *) NULL);
}
else
{
char *value;
value = (char *) xmalloc (1 + (i - start));
strncpy (value, &string[start], (i - start));
value[i - start] = '\0';
if (string[i])
++i;
*idx = i;
return (value);
}
}
/* A structure which associates a filename with its expansion. */
typedef struct {
char *filename;
char *expansion;
} FILENAME_LIST;
/* An array of remembered arguments and results. */
static FILENAME_LIST **names_and_files = (FILENAME_LIST **)NULL;
static int names_and_files_index = 0;
static int names_and_files_slots = 0;
/* Find the result for having already called info_find_fullpath () with
FILENAME. */
static char *
lookup_info_filename (filename)
char *filename;
{
if (filename && names_and_files)
{
register int i;
for (i = 0; names_and_files[i]; i++)
{
if (FILENAME_CMP (names_and_files[i]->filename, filename) == 0)
return (names_and_files[i]->expansion);
}
}
return (char *)NULL;;
}
/* Add a filename and its expansion to our list. */
static void
remember_info_filename (filename, expansion)
char *filename, *expansion;
{
FILENAME_LIST *new;
if (names_and_files_index + 2 > names_and_files_slots)
{
int alloc_size;
names_and_files_slots += 10;
alloc_size = names_and_files_slots * sizeof (FILENAME_LIST *);
names_and_files =
(FILENAME_LIST **) xrealloc (names_and_files, alloc_size);
}
new = (FILENAME_LIST *)xmalloc (sizeof (FILENAME_LIST));
new->filename = xstrdup (filename);
new->expansion = expansion ? xstrdup (expansion) : (char *)NULL;
names_and_files[names_and_files_index++] = new;
names_and_files[names_and_files_index] = (FILENAME_LIST *)NULL;
}
static void
maybe_initialize_infopath ()
{
if (!infopath_size)
{
infopath = (char *)
xmalloc (infopath_size = (1 + strlen (DEFAULT_INFOPATH)));
strcpy (infopath, DEFAULT_INFOPATH);
}
}
/* Add PATH to the list of paths found in INFOPATH. 2nd argument says
whether to put PATH at the front or end of INFOPATH. */
void
info_add_path (path, where)
char *path;
int where;
{
int len;
if (!infopath)
{
infopath = (char *)xmalloc (infopath_size = 200 + strlen (path));
infopath[0] = '\0';
}
len = strlen (path) + strlen (infopath);
if (len + 2 >= infopath_size)
infopath = (char *)xrealloc (infopath, (infopath_size += (2 * len) + 2));
if (!*infopath)
strcpy (infopath, path);
else if (where == INFOPATH_APPEND)
{
strcat (infopath, PATH_SEP);
strcat (infopath, path);
}
else if (where == INFOPATH_PREPEND)
{
char *temp = xstrdup (infopath);
strcpy (infopath, path);
strcat (infopath, PATH_SEP);
strcat (infopath, temp);
free (temp);
}
}
/* Make INFOPATH have absolutely nothing in it. */
void
zap_infopath ()
{
if (infopath)
free (infopath);
infopath = (char *)NULL;
infopath_size = 0;
}
/* Given a chunk of text and its length, convert all CRLF pairs at every
end-of-line into a single Newline character. Return the length of
produced text.
This is required because the rest of code is too entrenched in having
a single newline at each EOL; in particular, searching for various
Info headers and cookies can become extremely tricky if that assumption
breaks.
FIXME: this could also support Mac-style text files with a single CR
at the EOL, but what about random CR characters in non-Mac files? Can
we afford converting them into newlines as well? Maybe implement some
heuristics here, like in Emacs 20.
FIXME: is it a good idea to show the EOL type on the modeline? */
long
convert_eols (text, textlen)
char *text;
long textlen;
{
register char *s = text;
register char *d = text;
while (textlen--)
{
if (*s == '\r' && textlen && s[1] == '\n')
{
s++;
textlen--;
}
*d++ = *s++;
}
return (long)(d - text);
}
/* Read the contents of PATHNAME, returning a buffer with the contents of
that file in it, and returning the size of that buffer in FILESIZE.
FINFO is a stat struct which has already been filled in by the caller.
If the file turns out to be compressed, set IS_COMPRESSED to non-zero.
If the file cannot be read, return a NULL pointer. */
char *
filesys_read_info_file (pathname, filesize, finfo, is_compressed)
char *pathname;
long *filesize;
struct stat *finfo;
int *is_compressed;
{
long st_size;
*filesize = filesys_error_number = 0;
if (compressed_filename_p (pathname))
{
*is_compressed = 1;
return (filesys_read_compressed (pathname, filesize, finfo));
}
else
{
int descriptor;
char *contents;
*is_compressed = 0;
descriptor = open (pathname, O_RDONLY | O_BINARY, 0666);
/* If the file couldn't be opened, give up. */
if (descriptor < 0)
{
filesys_error_number = errno;
return ((char *)NULL);
}
/* Try to read the contents of this file. */
st_size = (long) finfo->st_size;
contents = (char *)xmalloc (1 + st_size);
if ((read (descriptor, contents, st_size)) != st_size)
{
filesys_error_number = errno;
close (descriptor);
free (contents);
return ((char *)NULL);
}
close (descriptor);
/* Convert any DOS-style CRLF EOLs into Unix-style NL.
Seems like a good idea to have even on Unix, in case the Info
files are coming from some Windows system across a network. */
*filesize = convert_eols (contents, st_size);
/* EOL conversion can shrink the text quite a bit. We don't
want to waste storage. */
if (*filesize < st_size)
contents = (char *)xrealloc (contents, 1 + *filesize);
return (contents);
}
}
/* Typically, pipe buffers are 4k. */
#define BASIC_PIPE_BUFFER (4 * 1024)
/* We use some large multiple of that. */
#define FILESYS_PIPE_BUFFER_SIZE (16 * BASIC_PIPE_BUFFER)
char *
filesys_read_compressed (pathname, filesize, finfo)
char *pathname;
long *filesize;
struct stat *finfo;
{
FILE *stream;
char *command, *decompressor;
char *contents = (char *)NULL;
*filesize = filesys_error_number = 0;
decompressor = filesys_decompressor_for_file (pathname);
if (!decompressor)
return ((char *)NULL);
command = (char *)xmalloc (15 + strlen (pathname) + strlen (decompressor));
/* Explicit .exe suffix makes the diagnostics of `popen'
better on systems where COMMAND.COM is the stock shell. */
sprintf (command, "%s%s < %s",
decompressor, STRIP_DOT_EXE ? ".exe" : "", pathname);
#if !defined (BUILDING_LIBRARY)
if (info_windows_initialized_p)
{
char *temp;
temp = (char *)xmalloc (5 + strlen (command));
sprintf (temp, "%s...", command);
message_in_echo_area ("%s", temp);
free (temp);
}
#endif /* !BUILDING_LIBRARY */
stream = popen (command, FOPEN_RBIN);
free (command);
/* Read chunks from this file until there are none left to read. */
if (stream)
{
long offset, size;
char *chunk;
offset = size = 0;
chunk = (char *)xmalloc (FILESYS_PIPE_BUFFER_SIZE);
while (1)
{
int bytes_read;
bytes_read = fread (chunk, 1, FILESYS_PIPE_BUFFER_SIZE, stream);
if (bytes_read + offset >= size)
contents = (char *)xrealloc
(contents, size += (2 * FILESYS_PIPE_BUFFER_SIZE));
memcpy (contents + offset, chunk, bytes_read);
offset += bytes_read;
if (bytes_read != FILESYS_PIPE_BUFFER_SIZE)
break;
}
free (chunk);
if (pclose (stream) == -1)
{
if (contents)
free (contents);
contents = (char *)NULL;
filesys_error_number = errno;
}
else
{
*filesize = convert_eols (contents, offset);
contents = (char *)xrealloc (contents, 1 + *filesize);
}
}
else
{
filesys_error_number = errno;
}
#if !defined (BUILDING_LIBARARY)
if (info_windows_initialized_p)
unmessage_in_echo_area ();
#endif /* !BUILDING_LIBRARY */
return (contents);
}
/* Return non-zero if FILENAME belongs to a compressed file. */
int
compressed_filename_p (filename)
char *filename;
{
char *decompressor;
/* Find the final extension of this filename, and see if it matches one
of our known ones. */
decompressor = filesys_decompressor_for_file (filename);
if (decompressor)
return (1);
else
return (0);
}
/* Return the command string that would be used to decompress FILENAME. */
char *
filesys_decompressor_for_file (filename)
char *filename;
{
register int i;
char *extension = (char *)NULL;
/* Find the final extension of FILENAME, and see if it appears in our
list of known compression extensions. */
for (i = strlen (filename) - 1; i > 0; i--)
if (filename[i] == '.')
{
extension = filename + i;
break;
}
if (!extension)
return ((char *)NULL);
for (i = 0; compress_suffixes[i].suffix; i++)
if (FILENAME_CMP (extension, compress_suffixes[i].suffix) == 0)
return (compress_suffixes[i].decompressor);
#if defined (__MSDOS__)
/* If no other suffix matched, allow any extension which ends
with `z' to be decompressed by gunzip. Due to limited 8+3 DOS
file namespace, we can expect many such cases, and supporting
every weird suffix thus produced would be a pain. */
if (extension[strlen (extension) - 1] == 'z' ||
extension[strlen (extension) - 1] == 'Z')
return "gunzip";
#endif
return ((char *)NULL);
}
/* The number of the most recent file system error. */
int filesys_error_number = 0;
/* A function which returns a pointer to a static buffer containing
an error message for FILENAME and ERROR_NUM. */
static char *errmsg_buf = (char *)NULL;
static int errmsg_buf_size = 0;
char *
filesys_error_string (filename, error_num)
char *filename;
int error_num;
{
int len;
char *result;
if (error_num == 0)
return ((char *)NULL);
result = strerror (error_num);
len = 4 + strlen (filename) + strlen (result);
if (len >= errmsg_buf_size)
errmsg_buf = (char *)xrealloc (errmsg_buf, (errmsg_buf_size = 2 + len));
sprintf (errmsg_buf, "%s: %s", filename, result);
return (errmsg_buf);
}
/* Check for "dir" with all the possible info and compression suffixes,
in combination. */
int
is_dir_name (filename)
char *filename;
{
unsigned i;
for (i = 0; info_suffixes[i]; i++)
{
unsigned c;
char trydir[50];
strcpy (trydir, "dir");
strcat (trydir, info_suffixes[i]);
if (strcasecmp (filename, trydir) == 0)
return 1;
for (c = 0; compress_suffixes[c].suffix; c++)
{
char dir_compressed[50]; /* can be short */
strcpy (dir_compressed, trydir);
strcat (dir_compressed, compress_suffixes[c].suffix);
if (strcasecmp (filename, dir_compressed) == 0)
return 1;
}
}
return 0;
}