#define _GNU_SOURCE
#include <dirent.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
int filter(const struct dirent *d) {
return strlen(d->d_name) > 2;
}
int
main(void)
{
struct dirent **namelist;
int n;
n = scandirat(AT_FDCWD, ".", &namelist, filter, alphasort);
if (n == -1) {
perror("scandir");
exit(EXIT_FAILURE);
}
while (n--) {
printf("%s (%lu)\n", namelist[n]->d_name, strlen(namelist[n]->d_name));
free(namelist[n]);
}
free(namelist);
exit(EXIT_SUCCESS);
}
> clang -o /tmp/test test.c -fsanitize=memory -Wno-error
> /tmp/test
Uninitialized bytes in strlen at offset 0 inside [0x72d000000043, 2)
==374088==WARNING: MemorySanitizer: use-of-uninitialized-value
#0 0x55b4602f2d3c in filter (/tmp/test+0x109d3c)
#1 0x7f5179f5ee8a (/usr/lib64/libc.so.6+0xc7e8a)
#2 0x55b4602f2e48 in main (/tmp/test+0x109e48)
#3 0x7f5179ebd166 (/usr/lib64/libc.so.6+0x26166)
#4 0x7f5179ebd216 in __libc_start_main (/usr/lib64/libc.so.6+0x26216)
#5 0x55b460257170 in _start (/tmp/test+0x6e170)
SUMMARY: MemorySanitizer: use-of-uninitialized-value (/tmp/test+0x109d3c) in filter
Exiting
