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C perror() function

C library function - perror()

The perror() function is used to print an error message to stderr based on the error state stored in errno. The string pointed to by string, followed by a colon and a space, is printed to the standard error stream if string is not NULL.

Syntax:

void perror(const char *str)

Parameters:

Name Description Required /Optional
str Contains a custom message. Required

Return value

  • This function does not return any value.

Example: The following example shows the usage of perror() function.

#include <stdio.h>
#include <stdlib.h>
 
int main(void)
{
   FILE *fh;
 
   if ((fh = fopen("test1.txt","r")) == NULL)
   {
      perror("Can not open the said file.");
   }
   return 0;
}

Output:

Can not open the said file.: No such file or directory

C Programming Code Editor:

Previous C Programming: C puts()



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