C library function - tmpnam()

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Description

The C library function char *tmpnam(char *str) generates and returns a valid temporary filename which does not exist. If str is null then it simply returns the tmp file name.

Declaration

Following is the declaration for tmpnam() function.

char *tmpnam(char *str)

Parameters

• str − This is the pointer to an array of chars where the proposed tempname will be stored as a C string.

Return Value

• Return value is a pointer to the C string containing the proposed name for a temporary file. If str was a null pointer, this points to an internal buffer that will be overwritten the next time this function is called.

• If str was not a null pointer, str is returned. If the function fails to create a suitable filename, it returns a null pointer.

Example

The following example shows the usage of tmpnam() function.

#include <stdio.h>

int main () {
   char buffer[L_tmpnam];
   char *ptr;

   tmpnam(buffer);
   printf("Temporary name 1: %s\n", buffer);
 
   ptr = tmpnam(NULL);
   printf("Temporary name 2: %s\n", ptr);

   return(0);
}

Let us compile and run the above program to produce the following result −

Temporary name 1: /tmp/filebaalTb
Temporary name 2: /tmp/filedCIbb0