我正在linux ubuntu上的C 中的文件crawler 16.04。
基本上,它应该浏览一个目录,将文件字节大小添加到链接列表并相应地制作新节点。因此,如果我有一个单个文件夹,其中有几个文件,则可以很好地计算它们
我的问题是,如果我有一个文件夹,其中包含另一个文件夹,我会得到一个分离错误,当用GNU-Debugger测试时,如下所示:
程序接收到信号sigsegv,分段故障。 __strcpy_sse2_unaligned() at ../sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.s:714 714 ../sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.s:没有这样的文件或目录。
根据堆栈溢出帖子1我需要以某种方式安装库,但是安装适当的版本存在问题。
我不认为这是我的问题,因为故障发生的位置,根据调试器,当调用递归函数内部的内部时,它应该挖掘到目录并获取数据。在我的主循环中调用相同的功能以遍历顶级目录,并且在单层上正常工作,当我嵌套目录的时候我有问题。附加是参考的完整源代码,它有点长,但是如果使用相同的参数调用,则该错误应易于复制:
// Directory crawler
// Written by Kaz
/*
1) Start at a user provided directory
2) Descend the file tree while tracking each file
3) Groups each file by it's size based off user argument
4) Print a histogram of file sizes in a bin wide groupings
*/
#include<iostream>
#include <dirent.h>
#include<string.h>
#include <errno.h>
#include <stdio.h>
#include<string>
#include <stdint.h>
#include <sys/types.h>
#include <sys/stat.h>
#include<stdlib.h>
using namespace std;
int binCount = 0; // count of total bins
struct node{
node* next, *prev;
int count, name, min, max;
node(){
prev = NULL;
next = NULL;
count = 0;
name = binCount;
min = 0;
max = 0;
}
};
node *nextNode(node* previousNode){
node *nextLink = new node;
nextLink ->name = binCount;
nextLink->prev = previousNode;
nextLink->next = NULL;
nextLink->count = 1;
nextLink->min = previousNode->max + 1;
nextLink->max = ((previousNode->max)*2) + 1;
previousNode ->next = nextLink;
return nextLink;
}
void traverseNewDirectory(node * here, char *dirName){
DIR * nwd;
struct dirent *dip;
node * current;
current = here;
bool isadirectory,isHidden;
if((nwd = opendir(dirName))== NULL){
perror("Can't open derived directory");
return;
}
while ((dip = readdir(nwd)) != NULL){
isadirectory = false;
isHidden = false;
if((dip -> d_type) == DT_UNKNOWN ){
struct stat stbuf;
stat(dip->d_name, &stbuf);
isadirectory = S_ISDIR(stbuf.st_mode);
}
else if((dip -> d_type) == DT_DIR ){
if((strcmp(dip->d_name, ".") == 0) || (strcmp(dip->d_name, "..")) == 0){
isHidden = true;
isadirectory = true;
}
else{
isadirectory = true;
}
}
else{
if((dip-> d_reclen <= current->max)&&(dip->d_reclen >=current->min)){
current->count = current->count+1;
}
else if(dip->d_reclen < current->min){
node*temp = current->prev;
while(temp->prev != NULL){
if((dip-> d_reclen <= current->max)&&(dip->d_reclen >=current->min)){
current->count = current->count+1;
break;
}
else if(dip->d_reclen < current->min){
temp = current->prev;
}
}
}
else{
current -> next = nextNode(current);
current = current -> next;
binCount++;
}
}
if(isadirectory){
char *path;
strcpy(path,dirName);
strcat(path, "/");
strcat(path,dip->d_name);
strcat(path, " ");
if(isHidden == true){
}
else{
traverseNewDirectory(current, path);
}
}
}
while ( ( closedir (nwd) == -1) && ( errno == EINTR) );
}
void printHistogram(node *head){
node*temp;
temp = head;
while(temp!=NULL){
cout << "[B " << temp->name << "] from " << temp->min << " to " << temp->max << " : ";
for(int i = 0; i < temp->count; i++){
cout << "x";
}
cout << endl;
temp = temp->next;
}
}
int main(int argc,char *argv[]){
// Ensures that a valid directory is provided by the cmd line argument
if (argc != 3){
if(argc == 1){
fprintf (stderr, " argc = %d no directory given n", argc);
return 1;
}
else if(argc == 2){
fprintf (stderr, " argc = %d no size given n", argc);
return 2;
}
else{
fprintf(stderr, "argc = %d invalid parameters n", argc);
return 3;
}
}
DIR * cwd; // current working directory pointer
struct dirent *cwdP; // pointer to dirent struct
int binWidth; // variable for the width of the grouping in the histogram
binWidth = atoi(argv[2]);
node *first = new node;
binCount++;
first->max = binWidth - 1;
node * current;
current = first;
bool isadirectory,isHidden;
if((cwd = opendir(argv[1]))== NULL){
perror("Can't open main directory");
return 2;
}
while ((cwdP = readdir(cwd)) != NULL){
isadirectory = false;
isHidden = false;
if((cwdP -> d_type) == DT_UNKNOWN ){
struct stat stbuf;
stat(cwdP->d_name, &stbuf);
isadirectory = S_ISDIR(stbuf.st_mode);
}
else if((cwdP -> d_type) == DT_DIR ){
if((strcmp(cwdP->d_name, ".") == 0) || (strcmp(cwdP->d_name, "..")) == 0){
isHidden = true;
isadirectory = true;
}
else{
isadirectory = true;
}
}
else{
if((cwdP-> d_reclen <= current->max)&&(cwdP->d_reclen >=current->min)){
current->count = current->count+1;
}
else if(cwdP->d_reclen < current->min){
node*temp = current->prev;
while(temp->prev != NULL){
if((cwdP-> d_reclen <= current->max)&&(cwdP->d_reclen >=current->min)){
current->count = current->count+1;
break;
}
else if(cwdP->d_reclen < current->min){
temp = current->prev;
}
}
}
else{
current -> next = nextNode(current);
current = current -> next;
binCount++;
}
}
if(isadirectory){
char *fullPath;
strcpy(fullPath,argv[1]);
strcat(fullPath,"/");
strcat(fullPath,cwdP->d_name);
strcat(fullPath, " ");
if(isHidden == true){
}
else{
traverseNewDirectory(current, fullPath);
}
}
}
while ( ( closedir (cwd) == -1) && ( errno == EINTR) );
printHistogram(first);
return 0;
}
不,这是你的错;)
它在 strcpy
中segfault segfault是直接的赠品,当构造路径时您没有分配任何内存(或者您没有足够的存储器来为字符串,或者不太常见的是您在其他地方有堆腐败)。因此,查看您这样做的两个地方:
char *path;
strcat(path, "/");
strcpy(path,dirName);
strcat(path, "/");
strcat(path,dip->d_name);
strcat(path, " ");
您最好为此分配足够的内存。目前,您只是根据从未初始化为path
的值将字符串复制到未知的内存位置。
真的,我不知道为什么您在C 中编写类似C的代码。您正在使用C 。因此,只需使用std::string
即可为您负责内存管理即可。即使这样也可能会这样:
std::string path = std::string( dirName ) + "/" + dip->d_name;
然后,您可以通过访问C字符串来重复:
traverseNewDirectory(current, path.c_str());
您的代码也可能还有其他问题。我还没有花时间阅读它,但是在指针使用上看起来很重,几乎没有评论,而且过于复杂。所有这些都是麻烦的成分。