git/abspath.c
René Scharfe 679eebe24d abspath: convert absolute_path() to strbuf
Move most of the code of absolute_path() into the new function
strbuf_add_absolute_path() and in the process transform it to use
struct strbuf and xgetcwd() instead of a PATH_MAX-sized buffer,
which can be too small on some file systems.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-26 11:06:06 -07:00

184 lines
4.4 KiB
C

#include "cache.h"
/*
* Do not use this for inspecting *tracked* content. When path is a
* symlink to a directory, we do not want to say it is a directory when
* dealing with tracked content in the working tree.
*/
int is_directory(const char *path)
{
struct stat st;
return (!stat(path, &st) && S_ISDIR(st.st_mode));
}
/* We allow "recursive" symbolic links. Only within reason, though. */
#define MAXDEPTH 5
/*
* Return the real path (i.e., absolute path, with symlinks resolved
* and extra slashes removed) equivalent to the specified path. (If
* you want an absolute path but don't mind links, use
* absolute_path().) The return value is a pointer to a static
* buffer.
*
* The input and all intermediate paths must be shorter than MAX_PATH.
* The directory part of path (i.e., everything up to the last
* dir_sep) must denote a valid, existing directory, but the last
* component need not exist. If die_on_error is set, then die with an
* informative error message if there is a problem. Otherwise, return
* NULL on errors (without generating any output).
*
* If path is our buffer, then return path, as it's already what the
* user wants.
*/
static const char *real_path_internal(const char *path, int die_on_error)
{
static struct strbuf sb = STRBUF_INIT;
char *retval = NULL;
/*
* If we have to temporarily chdir(), store the original CWD
* here so that we can chdir() back to it at the end of the
* function:
*/
struct strbuf cwd = STRBUF_INIT;
int depth = MAXDEPTH;
char *last_elem = NULL;
struct stat st;
/* We've already done it */
if (path == sb.buf)
return path;
if (!*path) {
if (die_on_error)
die("The empty string is not a valid path");
else
goto error_out;
}
strbuf_reset(&sb);
strbuf_addstr(&sb, path);
while (depth--) {
if (!is_directory(sb.buf)) {
char *last_slash = find_last_dir_sep(sb.buf);
if (last_slash) {
last_elem = xstrdup(last_slash + 1);
strbuf_setlen(&sb, last_slash - sb.buf + 1);
} else {
last_elem = xmemdupz(sb.buf, sb.len);
strbuf_reset(&sb);
}
}
if (sb.len) {
if (!cwd.len && strbuf_getcwd(&cwd)) {
if (die_on_error)
die_errno("Could not get current working directory");
else
goto error_out;
}
if (chdir(sb.buf)) {
if (die_on_error)
die_errno("Could not switch to '%s'",
sb.buf);
else
goto error_out;
}
}
if (strbuf_getcwd(&sb)) {
if (die_on_error)
die_errno("Could not get current working directory");
else
goto error_out;
}
if (last_elem) {
if (sb.len && !is_dir_sep(sb.buf[sb.len - 1]))
strbuf_addch(&sb, '/');
strbuf_addstr(&sb, last_elem);
free(last_elem);
last_elem = NULL;
}
if (!lstat(sb.buf, &st) && S_ISLNK(st.st_mode)) {
struct strbuf next_sb = STRBUF_INIT;
ssize_t len = strbuf_readlink(&next_sb, sb.buf, 0);
if (len < 0) {
if (die_on_error)
die_errno("Invalid symlink '%s'",
sb.buf);
else
goto error_out;
}
strbuf_swap(&sb, &next_sb);
strbuf_release(&next_sb);
} else
break;
}
retval = sb.buf;
error_out:
free(last_elem);
if (cwd.len && chdir(cwd.buf))
die_errno("Could not change back to '%s'", cwd.buf);
strbuf_release(&cwd);
return retval;
}
const char *real_path(const char *path)
{
return real_path_internal(path, 1);
}
const char *real_path_if_valid(const char *path)
{
return real_path_internal(path, 0);
}
/*
* Use this to get an absolute path from a relative one. If you want
* to resolve links, you should use real_path.
*/
const char *absolute_path(const char *path)
{
static struct strbuf sb = STRBUF_INIT;
strbuf_reset(&sb);
strbuf_add_absolute_path(&sb, path);
return sb.buf;
}
/*
* Unlike prefix_path, this should be used if the named file does
* not have to interact with index entry; i.e. name of a random file
* on the filesystem.
*/
const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
{
static struct strbuf path = STRBUF_INIT;
#ifndef GIT_WINDOWS_NATIVE
if (!pfx_len || is_absolute_path(arg))
return arg;
strbuf_reset(&path);
strbuf_add(&path, pfx, pfx_len);
strbuf_addstr(&path, arg);
#else
char *p;
/* don't add prefix to absolute paths, but still replace '\' by '/' */
strbuf_reset(&path);
if (is_absolute_path(arg))
pfx_len = 0;
else if (pfx_len)
strbuf_add(&path, pfx, pfx_len);
strbuf_addstr(&path, arg);
for (p = path.buf + pfx_len; *p; p++)
if (*p == '\\')
*p = '/';
#endif
return path.buf;
}