C language, how to check if a file exists and permissions information

Press function access, header file IO.h (Linux by using Unistd.h
int access (const char *filename, int amode);

A amode parameter of 0 indicates the existence of the check file, assuming the file exists. Returns 0. Does not exist, returns-1.

This function can also check other file attributes:

06 Checking Read and Write permissions
04 Checking Read Permissions
02 Checking Write permissions
01 Check Run Permissions
00 checking the existence of files

Experiment successfully under UNIX and VC.

The advantage is fopen (.., "R") is not good, when no read access to a failure.

And this even if this file does not have Read permission. It is also possible to infer whether the file exists in the

The presence returns 0. Does not exist return-1

#include <stdio.h>int main () {printf ("%d", Access ("Test.db", 0));}

Test procedure

#define __WINDOWS__//WINDOWS systems use//#define __LINUX__//LINUX systems using #ifdef __windows__#include <io.h> #endif #ifdef __linux__#include <unistd.h> #endif # include <stdio.h> #include <stdlib.h> #define FILE_NAME  " test.db "int main (void) {/* Check for existence */if ((Access (file_name, 0))! =-1) {printf (" file [%s] exists\n ", File _NAME);/* Check for Write permission */if ((_access (file_name, 2))! =-1) {printf ("FILE [%s] has write permission\n", file_name);} else{printf ("File [%s] has not write permission\n", file_name);}} else{printf ("File [%s] don ' t exists\n", file_name);}}

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C language, how to check if a file exists and permissions information