/*
* I'm tired of doing "vsnprintf()" etc just to open a
* file, so here's a "return static buffer with printf"
* interface for paths.
*
* It's obviously not thread-safe. Sue me. But it's quite
* useful for doing things like
*
* f = open(mkpath("%s/%s.perf", base, name), O_RDONLY);
*
* which is what it's designed for.
*/
#include "cache.h"
static char bad_path[] = "/bad-path/";
/*
* Two hacks:
*/
static const char *get_perf_dir(void)
{
return ".";
}
/*
* If libc has strlcpy() then that version will override this
* implementation:
*/
size_t __weak strlcpy(char *dest, const char *src, size_t size)
{
size_t ret = strlen(src);
if (size) {
size_t len = (ret >= size) ? size - 1 : ret;
memcpy(dest, src, len);
dest[len] = '\0';
}
return ret;
}
static char *get_pathname(void)
{
static char pathname_array[4][PATH_MAX];
static int idx;
return pathname_array[3 & ++idx];
}
static char *cleanup_path(char *path)
{
/* Clean it up */
if (!memcmp(path, "./", 2)) {
path += 2;
while (*path == '/')
path++;
}
return path;
}
static char *perf_vsnpath(char *buf, size_t n, const char *fmt, va_list args)
{
const char *perf_dir = get_perf_dir();
size_t len;
len = strlen(perf_dir);
if (n < len + 1)
goto bad;
memcpy(buf, perf_dir, len);
if (len && !is_dir_sep(perf_dir[len-1]))
buf[len++] = '/';
len += vsnprintf(buf + len, n - len, fmt, args);
if (len >= n)
goto bad;
return cleanup_path(buf);
bad:
strlcpy(buf, bad_path, n);
return buf;
}
char *perf_pathdup(const char *fmt, ...)
{
char path[PATH_MAX];
va_list args;
va_start(args, fmt);
(void)perf_vsnpath(path, sizeof(path), fmt, args);
va_end(args);
return xstrdup(path);
}
char *mkpath(const char *fmt, ...)
{
va_list args;
unsigned len;
char *pathname = get_pathname();
va_start(args, fmt);
len = vsnprintf(pathname, PATH_MAX, fmt, args);
va_end(args);
if (len >= PATH_MAX)
return bad_path;
return cleanup_path(pathname);
}
char *perf_path(const char *fmt, ...)
{
const char *perf_dir = get_perf_dir();
char *pathname = get_pathname();
va_list args;
unsigned len;
len = strlen(perf_dir);
if (len > PATH_MAX-100)
return bad_path;
memcpy(pathname, perf_dir, len);
if (len && perf_dir[len-1] != '/')
pathname[len++] = '/';
va_start(args, fmt);
len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
va_end(args);
if (len >= PATH_MAX)
return bad_path;
return cleanup_path(pathname);
}
/* strip arbitrary amount of directory separators at end of path */
static inline int chomp_trailing_dir_sep(const char *path, int len)
{
while (len && is_dir_sep(path[len - 1]))
len--;
return len;
}
/*
* If path ends with suffix (complete path components), returns the
* part before suffix (sans trailing directory separators).
* Otherwise returns NULL.
*/
char *strip_path_suffix(const char *path, const char *suffix)
{
int path_len = strlen(path), suffix_len = strlen(suffix);
while (suffix_len) {
if (!path_len)
return NULL;
if (is_dir_sep(path[path_len - 1])) {
if (!is_dir_sep(suffix[suffix_len - 1]))
return NULL;
path_len = chomp_trailing_dir_sep(path, path_len);
suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
}
else if (path[--path_len] != suffix[--suffix_len])
return NULL;
}
if (path_len && !is_dir_sep(path[path_len - 1]))
return NULL;
return strndup(path, chomp_trailing_dir_sep(path, path_len));
}
