busybox/libbb/find_root_device.c

39 lines
849 B
C

/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <dirent.h>
#include <stdlib.h>
#include "libbb.h"
char *find_block_device(char *path)
{
DIR *dir;
struct dirent *entry;
struct stat st;
dev_t dev;
char *retpath=NULL;
if(stat(path, &st) || !(dir = opendir("/dev"))) return NULL;
dev = (st.st_mode & S_IFMT) == S_IFBLK ? st.st_rdev : st.st_dev;
while((entry = readdir(dir)) != NULL) {
char devpath[PATH_MAX];
sprintf(devpath,"/dev/%s", entry->d_name);
if(!stat(devpath, &st) && S_ISBLK(st.st_mode) && st.st_rdev == dev) {
retpath = bb_xstrdup(devpath);
break;
}
}
closedir(dir);
return retpath;
}