我正在编写一个程序，在目录中搜索请求的文件。命令行上的输出将是文件的目录路径，对于找到的每个具有相同名称的文件。出于某种原因，当我用valgrind运行它时，它会导致内存泄漏。我在windows盒子上的linux虚拟机上运行。
我更新了我的valgrind输出。我没有泄漏，但仍然有错误。
这是我的代码：
#include <stdio.h>
#include <stdlib.h>
#include <dirent.h>
#include <sys/types.h>
#include <string.h>
struct tree_t {
char *name;
int nchildren;
struct tree_t **children;
};
char *make_path(const char *dirname, const char *filename) {
char *fullpath = (char *) malloc((strlen(dirname) + strlen(filename) + 1 + 1) * sizeof(char));
strcat(fullpath, dirname);
strcat(fullpath, "/");
strcat(fullpath, filename);
return fullpath;
}
struct tree_t *get_tree(const char *name) {
struct tree_t *tree = (struct tree_t *) malloc(sizeof(struct tree_t));
char *namecp = (char *) malloc((strlen(name) + 1) * sizeof(char));
strcpy(namecp, name);
tree->name = namecp;
DIR *dir = opendir(name);
if (dir == NULL) {
tree->nchildren = 0;
} else {
tree->nchildren = 0;
int numsubdirs = 0;
struct dirent *entry;
while((entry = readdir(dir))) {
if (strcmp(entry->d_name,".") != 0 && strcmp(entry->d_name,"..") != 0) {
tree->nchildren++;
DIR *subdir = opendir(entry->d_name);
if (subdir != NULL) {
numsubdirs++;
}
closedir(subdir);
}
}
tree->children = (struct tree_t **) malloc(numsubdirs * sizeof(struct tree_t **));
}
closedir(dir);
return tree;
}
void find_in_tree(const struct tree_t *root, const char *filename) {
int i = 0;
DIR *dir = opendir(root->name);
if (dir != NULL) {
struct dirent *entry;
while((entry = readdir(dir))) {
if (strcmp(entry->d_name,".") != 0 && strcmp(entry->d_name,"..") != 0) {
char *fullpath = make_path(root->name, entry->d_name);
DIR *subdir = opendir(fullpath);
if (subdir != NULL) {
root->children[i] = get_tree(fullpath);
find_in_tree(root->children[i], filename);
free(root->children[i]);
i++;
} else if (strcmp(entry->d_name, filename) == 0) {
printf("%sn", fullpath);
}
free(fullpath);
}
}
}
free(root->name);
free(root->children);
}
int main(int argc, char **args) {
printf("What root directory do you want to start from?n");
char rootdir[256];
scanf("%s",rootdir);
char searchfile[256];
printf("What file do you want to search for?n");
int result = scanf("%s",searchfile);
if (result == EOF) {
printf("n");
exit(1);
}
struct tree_t *root = get_tree(rootdir);
find_in_tree(root, searchfile);
free(root);
return 0;
}
这就是我的内存检查运行后的样子。
[vosterjl@clark ~]$ valgrind --tool=memcheck --leak-check=yes -v --track-origins=yes ./dirch
==1464== Memcheck, a memory error detector
==1464== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et al.
==1464== Using Valgrind-3.5.0 and LibVEX; rerun with -h for copyright info
==1464== Command: ./dirch
==1464==
--1464-- Valgrind options:
--1464-- --tool=memcheck
--1464-- --leak-check=yes
--1464-- -v
--1464-- --track-origins=yes
--1464-- Contents of /proc/version:
--1464-- Linux version 2.6.18-274.17.1.el5 (mockbuild@hs20-bc2-5.build.redhat.com) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-51)) #1 SMP Wed Jan 4 22:45:44 EST 2012
--1464-- Arch and hwcaps: AMD64, amd64-sse3-cx16
--1464-- Page sizes: currently 4096, max supported 4096
--1464-- Valgrind library directory: /usr/lib64/valgrind
--1464-- Reading syms from /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch (0x400000)
--1464-- Reading syms from /usr/lib64/valgrind/memcheck-amd64-linux (0x38000000)
--1464-- object doesn't have a dynamic symbol table
--1464-- Reading syms from /lib64/ld-2.5.so (0x3ca2e00000)
--1464-- Reading suppressions file: /usr/lib64/valgrind/default.supp
--1464-- REDIR: 0x3ca2e14730 (strlen) redirected to 0x3803e767 (vgPlain_amd64_linux_REDIR_FOR_strlen)
--1464-- Reading syms from /usr/lib64/valgrind/vgpreload_core-amd64-linux.so (0x4802000)
--1464-- Reading syms from /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so (0x4a03000)
==1464== WARNING: new redirection conflicts with existing -- ignoring it
--1464-- new: 0x3ca2e14730 (strlen ) R-> 0x04a070b0 strlen
--1464-- REDIR: 0x3ca2e14550 (index) redirected to 0x4a06f20 (index)
--1464-- REDIR: 0x3ca2e14700 (strcmp) redirected to 0x4a07180 (strcmp)
--1464-- Reading syms from /lib64/libc-2.5.so (0x3ca3200000)
--1464-- REDIR: 0x3ca3279f60 (rindex) redirected to 0x4a06dd0 (rindex)
--1464-- REDIR: 0x3ca3279b70 (strlen) redirected to 0x4a07070 (strlen)
Directory?
dir1
Search file?
test.txt
--1464-- REDIR: 0x3ca3274de0 (malloc) redirected to 0x4a0608a (malloc)
--1464-- REDIR: 0x3ca3279630 (strcpy) redirected to 0x4a08a70 (strcpy)
--1464-- REDIR: 0x3ca327ac80 (memmove) redirected to 0x4a07370 (memmove)
--1464-- REDIR: 0x3ca3272890 (free) redirected to 0x4a05c9a (free)
--1464-- REDIR: 0x3ca3279280 (strcat) redirected to 0x4a07d40 (strcat)
==1464== Invalid write of size 8
==1464== at 0x400AF3: find_in_tree (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== by 0x400C1F: main (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== Address 0x4c2c170 is 0 bytes after a block of size 0 alloc'd
==1464== at 0x4A0610C: malloc (vg_replace_malloc.c:195)
==1464== by 0x4009D2: get_tree (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== by 0x400C0B: main (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464==
==1464== Invalid read of size 8
==1464== at 0x400B0B: find_in_tree (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== by 0x400C1F: main (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== Address 0x4c2c170 is 0 bytes after a block of size 0 alloc'd
==1464== at 0x4A0610C: malloc (vg_replace_malloc.c:195)
==1464== by 0x4009D2: get_tree (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== by 0x400C0B: main (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464==
--1464-- REDIR: 0x3ca32795f0 (strcmp) redirected to 0x4a07140 (strcmp)
dir1/dir2/test.txt
==1464== Invalid read of size 8
==1464== at 0x400B2C: find_in_tree (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== by 0x400C1F: main (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== Address 0x4c2c170 is 0 bytes after a block of size 0 alloc'd
==1464== at 0x4A0610C: malloc (vg_replace_malloc.c:195)
==1464== by 0x4009D2: get_tree (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== by 0x400C0B: main (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464==
dir1/test.txt
Search file?
--1464-- REDIR: 0x3ca327ae20 (memset) redirected to 0x4a07320 (memset)
==1464==
==1464== HEAP SUMMARY:
==1464== in use at exit: 0 bytes in 0 blocks
==1464== total heap usage: 22 allocs, 22 frees, 262,763 bytes allocated
==1464==
==1464== All heap blocks were freed -- no leaks are possible
==1464==
==1464== ERROR SUMMARY: 6 errors from 3 contexts (suppressed: 4 from 4)
==1464==
==1464== 2 errors in context 1 of 3:
==1464== Invalid read of size 8
==1464== at 0x400B2C: find_in_tree (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== by 0x400C1F: main (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== Address 0x4c2c170 is 0 bytes after a block of size 0 alloc'd
==1464== at 0x4A0610C: malloc (vg_replace_malloc.c:195)
==1464== by 0x4009D2: get_tree (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== by 0x400C0B: main (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464==
==1464==
==1464== 2 errors in context 2 of 3:
==1464== Invalid read of size 8
==1464== at 0x400B0B: find_in_tree (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== by 0x400C1F: main (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== Address 0x4c2c170 is 0 bytes after a block of size 0 alloc'd
==1464== at 0x4A0610C: malloc (vg_replace_malloc.c:195)
==1464== by 0x4009D2: get_tree (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== by 0x400C0B: main (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464==
==1464==
==1464== 2 errors in context 3 of 3:
==1464== Invalid write of size 8
==1464== at 0x400AF3: find_in_tree (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== by 0x400C1F: main (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== Address 0x4c2c170 is 0 bytes after a block of size 0 alloc'd
==1464== at 0x4A0610C: malloc (vg_replace_malloc.c:195)
==1464== by 0x4009D2: get_tree (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464== by 0x400C0B: main (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==1464==
--1464--
--1464-- used_suppression: 4 dl-hack3
==1464==
==1464== ERROR SUMMARY: 6 errors from 3 contexts (suppressed: 4 from 4)
任何事情都会有帮助的，谢谢！
对于您执行的每个opendir，都应该使用closedir关闭。请检查。这可能是你泄漏的源头。
Valgrind也向你指出了这一点
==468== 65,648 bytes in 2 blocks are definitely lost in loss record 3 of 3
==468== at 0x4A0610C: malloc (vg_replace_malloc.c:195)
==468== by 0x3CA3296822: __alloc_dir (in /lib64/libc-2.5.so)
==468== by 0x400A09: find_in_tree (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==468== by 0x400B0F: find_in_tree (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
==468== by 0x400C06: main (in /USERS/STUDENTS/S-Z/V/VOSTERJL/dirch)
信任valgrind，而不是您的代码。
例如：
char *make_path(const char *dirname, const char *filename) {
char *fullpath = (char *) malloc((strlen(dirname) + strlen(filename) + 1 + 1) * sizeof(char));
strcat(fullpath, dirname);
malloc()返回的内存未初始化。您还不能使用strcat()。
毫无疑问，还会有其他类似的问题。