我有代码使用boost列出目录内容,遍历每个文件,并做一些数据处理的东西。结果将打印到输出文件('histFile')。 在处理了~2555个文件后,我收到错误:
boost :: filesystem :: directory_iterator :: construct:打开的文件过多:“/ Users /.../.../.../ directory_with_files”
我的代码是:
for(int i = 0; i < 10000; i++) {
FILE *histFile;
string outputFileName = "somename";
bool ifRet = initFile(histFile, outputFileName.c_str(), "a"); // 1
fclose(histFile); // 2
}
如果我注释掉上面的最后两行('1'和'2'),代码就可以了。因此似乎'histFile'的副本被打开了,但我不明白怎么做!这是该方法的有效部分:
bool initFile(FILE *&ofFile, const char *fileName, const char *openType, int overwriteOption) {
if(overwriteOption < 0 || overwriteOption > 2) {
fprintf(stderr, "ERROR: ToolBox - initFile() : unknown 'overwriteOption' (%d), setting to (0)!\n", overwriteOption);
}
// Read-Only
if(openType == "r") {
if(ofFile = fopen(fileName, "r")) { return true; }
fprintf(stderr, "ERROR: Could not open file (%s)!\n", fileName);
return false;
}
// Appending:
if(openType == "a" || openType == "a+") {
// Check if file already exists
if(!fopen(fileName, "r")){
fprintf(stderr, "ERROR: (%s) File does not Exist, cannot append!\n", fileName);
return false;
}
if(ofFile = fopen(fileName, openType)) { return true; }
}
// Writing:
// if file already exists
if(FILE *temp = fopen(fileName, "r")){
if(overwriteOption == 2) {
fprintf(stderr, "ERROR: (%s) File Exists!\n", fileName);
return false;
}
if(overwriteOption == 1) {
}
if(overwriteOption == 0) {
char backupFileName[TB_CHARLIMIT], backupPrefix[TB_CHARLIMIT];
strcpy(backupFileName, fileName); // copy filename
// create a prefix w/ format '<YYYYMMDD>BACKUP_'
DateTime now;
sprintf(backupPrefix, "%s", now.getDateStr().c_str());
strcat(backupPrefix, "BACKUP_");
// add to copied filename, and move file
strcpy(backupFileName, prependFileName(backupFileName, backupPrefix));
moveFile(fileName, backupFileName);
}
fclose(temp);
}
if(ofFile = fopen(fileName, openType)) { return true; }
// Default: Return error and false
fprintf(stderr, "ERROR: Could not open file (%s)!\n", fileName);
return false;
}
指针/引用我做错了吗? 任何帮助非常感谢!
答案 0 :(得分:4)
当您测试文件是否存在时,您正在泄漏此代码中的句柄:
// Appending:
if(openType == "a" || openType == "a+") {
// Check if file already exists
if(!fopen(fileName, "r")){ // <-- the FILE* opened here is leaked
fprintf(stderr, "ERROR: (%s) File does not Exist, cannot append!\n", fileName);
return false;
}
if(ofFile = fopen(fileName, openType)) { return true; }
}
真的有理由进行检查吗?为什么不在文件尚不存在的情况下创建文件?