Sometimes you mistakenly unpack tens of thousands of files into a single directory and maybe your OS/filesystem is unhappy about deleting it. This is recursive rm(1) in pure C.

gistfile1.c

#include <sys/types.h>
#include <dirent.h>

/**
 * Usage: rm_all <dir-name>
 * From lkml...
 */

#define u32 unsigned int

#ifndef COMBSORT
#define COMBSORT(size, i, j, COMPARE, EXCHANGE) { \
	unsigned gap = size, more, i; \
	if (size) do { \
		if (gap > 1) gap = gap*10/13; \
		if (gap - 9 < 2) gap = 11; \
		for (i = size - 1, more = gap > 1; i >= gap; i--) { \
			int j = i - gap; \
			if (COMPARE) { EXCHANGE; more = 1; } } \
	} while (more); }
#endif

#ifndef exchange
#define exchange(x, y) do { typeof(x) z = x; x = y; y = z; } while (0)
#endif

int main (int argc, char *argv[])
{
	char *dirname = argv[1];
	unsigned dirnamelen = strlen(dirname);
	unsigned maxmap = 50000, namesize = 20 * maxmap, count, i, more = 1;
	struct { char *name; u32 ino; } map[maxmap], *mp;
	char names[namesize], *namep;
	struct dirent *de;	
	DIR *dir;

	dir = opendir(dirname);
	readdir(dir);
	readdir(dir);
more:
	for (mp = map, namep = names; mp < map + maxmap; mp++)
	{
		int len;
		if (!(de = readdir(dir)))
		{
			more = 0;
			break;
		}
		len = strlen(de->d_name);
		if (namep + len + 1 > names + namesize) break;
		mp->ino = de->d_ino;
		mp->name = namep;
		*namep++ = len;
		memcpy(namep, de->d_name, len);
		namep += len;
	}
	count = mp - map, i = 0;
	COMBSORT(count, i, j, map[i].ino < map[j].ino, exchange(map[i], map[j]));
	for (mp = map; i < count; i++, mp++)
	{
		char name[50], *p = name;
		memcpy (p, dirname, dirnamelen);
		p += dirnamelen;
		*p++ = '/';
		memcpy (p, mp->name + 1, *mp->name);
		p += *mp->name;
		*p = 0;
		unlink(name);
	}
	if (more) goto more;
	closedir(dir);
	return 0;

}