C language access() function: determine file access permissions

Function name : access

Header file : <io.h>

Function prototype : int access(const char *file,int auth);

Function : Determine file access permissions

Parameters : const char *file is the file name, int auth value of 0 indicates whether the test file exists, and value of 2 indicates whether the test file is writable.

Return value : If the test result is allowed, return 0, otherwise return -1

Program example : Determine whether the specified file exists and output a prompt

 #include<stdio.h>#include<io.h>intmain(void){printf(DoseNOTEXISTS.FILexits?n);printf(%s,access(NOTEXISTS.FIL,0)==0?YES:NO) ;putchar('n');return0;}

Running results

 DoesNOTEXIST.FILexist?NO