freebsd-dev/gnu/usr.bin/diff/dir.c
1993-06-29 08:13:44 +00:00

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/* Read, sort and compare two directories. Used for GNU DIFF.
Copyright (C) 1988, 1989, 1992 Free Software Foundation, Inc.
This file is part of GNU DIFF.
GNU DIFF 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.
GNU DIFF 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 GNU DIFF; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "diff.h"
static int compare_names ();
/* Read the directory named by DIR and store into DIRDATA a sorted vector
of filenames for its contents. DIR->desc == -1 means this directory is
known to be nonexistent, so set DIRDATA to an empty vector.
Return -1 (setting errno) if error, 0 otherwise. */
struct dirdata
{
char **files; /* Sorted names of files in dir, terminated by (char *) 0. */
char *data; /* Allocated storage for file names. */
};
static int
dir_sort (dir, dirdata)
struct file_data *dir;
struct dirdata *dirdata;
{
register struct direct *next;
register int i;
/* Address of block containing the files that are described. */
char **files;
/* Number of files in directory. */
int nfiles;
/* Allocated and used storage for file name data. */
char *data;
size_t data_alloc, data_used;
dirdata->files = 0;
dirdata->data = 0;
nfiles = 0;
if (dir->desc != -1)
{
/* Open the directory and check for errors. */
register DIR *reading = opendir (dir->name);
if (!reading)
return -1;
/* Initialize the table of filenames. */
data_alloc = max (1, (size_t) dir->stat.st_size);
data_used = 0;
dirdata->data = data = (char *) xmalloc (data_alloc);
/* Read the directory entries, and insert the subfiles
into the `data' table. */
while ((errno = 0, (next = readdir (reading)) != 0))
{
char *d_name = next->d_name;
size_t d_size;
/* Ignore the files `.' and `..' */
if (d_name[0] == '.'
&& (d_name[1] == 0 || (d_name[1] == '.' && d_name[2] == 0)))
continue;
if (excluded_filename (d_name))
continue;
d_size = strlen (d_name) + 1;
while (data_alloc < data_used + d_size)
dirdata->data = data = (char *) xrealloc (data, data_alloc *= 2);
bcopy (d_name, data + data_used, d_size);
data_used += d_size;
nfiles++;
}
if (errno)
{
int e = errno;
closedir (reading);
errno = e;
return -1;
}
#ifdef VOID_CLOSEDIR
closedir (reading);
#else
if (closedir (reading) != 0)
return -1;
#endif
}
/* Create the `files' table from the `data' table. */
dirdata->files = files = (char **) xmalloc (sizeof (char *) * (nfiles + 1));
for (i = 0; i < nfiles; i++)
{
files[i] = data;
data += strlen (data) + 1;
}
files[nfiles] = 0;
/* Sort the table. */
qsort (files, nfiles, sizeof (char *), compare_names);
return 0;
}
/* Sort the files now in the table. */
static int
compare_names (file1, file2)
char **file1, **file2;
{
return strcmp (*file1, *file2);
}
/* Compare the contents of two directories named in FILEVEC[0] and FILEVEC[1].
This is a top-level routine; it does everything necessary for diff
on two directories.
FILEVEC[0].desc == -1 says directory FILEVEC[0] doesn't exist,
but pretend it is empty. Likewise for FILEVEC[1].
HANDLE_FILE is a caller-provided subroutine called to handle each file.
It gets five operands: dir and name (rel to original working dir) of file
in dir 0, dir and name pathname of file in dir 1, and the recursion depth.
For a file that appears in only one of the dirs, one of the name-args
to HANDLE_FILE is zero.
DEPTH is the current depth in recursion, used for skipping top-level
files by the -S option.
Returns the maximum of all the values returned by HANDLE_FILE,
or 2 if trouble is encountered in opening files. */
int
diff_dirs (filevec, handle_file, depth)
struct file_data filevec[];
int (*handle_file) ();
int depth;
{
struct dirdata dirdata[2];
int val = 0; /* Return value. */
int i;
/* Get sorted contents of both dirs. */
for (i = 0; i < 2; i++)
if (dir_sort (&filevec[i], &dirdata[i]) != 0)
{
perror_with_name (filevec[i].name);
val = 2;
}
if (val == 0)
{
register char **files0 = dirdata[0].files;
register char **files1 = dirdata[1].files;
char *name0 = filevec[0].name;
char *name1 = filevec[1].name;
/* If `-S name' was given, and this is the topmost level of comparison,
ignore all file names less than the specified starting name. */
if (dir_start_file && depth == 0)
{
while (*files0 && strcmp (*files0, dir_start_file) < 0)
files0++;
while (*files1 && strcmp (*files1, dir_start_file) < 0)
files1++;
}
/* Loop while files remain in one or both dirs. */
while (*files0 || *files1)
{
/* Compare next name in dir 0 with next name in dir 1.
At the end of a dir,
pretend the "next name" in that dir is very large. */
int nameorder = (!*files0 ? 1 : !*files1 ? -1
: strcmp (*files0, *files1));
int v1 = (*handle_file) (name0, 0 < nameorder ? 0 : *files0++,
name1, nameorder < 0 ? 0 : *files1++,
depth + 1);
if (v1 > val)
val = v1;
}
}
for (i = 0; i < 2; i++)
{
if (dirdata[i].files)
free (dirdata[i].files);
if (dirdata[i].data)
free (dirdata[i].data);
}
return val;
}