__errno2() — Return reason code information

Standards

Standards / Extensions	C or C++	Dependencies
z/OS® UNIX	both

Format

int __errno2(void);

General description

The __errno2() function can be used when diagnosing application problems. This function enables z/OS XL C/C++ application programs to access additional diagnostic information, errno2 (errnojr), associated with errno. The errno2 may be set by the z/OS XL C/C++ runtime library, z/OS UNIX callable services or other callable services. The errno2 is intended for diagnostic display purposes only and it is not a programming interface. The __errno2() function is not portable.

Note: Not all functions set errno2 when errno is set. In the cases where errno2 is not set, the __errno2() function may return a residual value. You may use the __err2ad() function to clear errno2 to reduce the possibility of a residual value being returned.

Returned value

The __errno2() function is always successful. The returned value is intended for diagnostic display purposes only.

The returned value may input to the BPXMTEXT utility to produce detailed information about the reported error if available.

For more information about the return value, see the z/OS UNIX System Services Command Reference, z/OS UNIX System Services Programming: Assembler Callable Services Reference, and z/OS Language Environment Debugging Guide.

Example

CELEBE02

⁄* CELEBE02

   The following example's output only occurs
   if the buffer is flushed.

 *⁄
#include <errno.h>
#include <stdio.h>
int   main(void) {
   FILE *f;
   f = fopen("notafile","r");
   if (f==NULL) {
      perror("fopen() failed");
      printf("__errno2 = %08x\n", __errno2());
   }
   return(0);
}

Sample output of routine using __errno2(), CELEBE02:

fopen() failed: EDC5129I No such file or directory. __errno2 = 05620062

CELEBE08

#pragma runopts(posix(on))
#define _EXT
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>

int main(void){
  FILE *fp;
  /* add errno2 to perror message */
  setenv("_EDC_ADD_ERRNO2", "1", 1);
  fp = fopen("testfile.dat", "r");
  if (fp == NULL)
    perror("fopen() failed");
	  return 0;
}

Sample output of routine using _EDC_ADD_ERRNO2, CELEBE08:

fopen() failed: EDC5129I No such file or directory. (errno2=0x05620062)

CELEBE09

#pragma runopts(posix(on))
#define _EXT
#include <stdio.h>
#include <errno.h>

int main(void){
  FILE *f;
  f = fopen("testfile.dat", "r");
  if (f == NULL){
    perror("fopen() failed");
    printf("__errno2 = %08x\n", __errno2());
  }

  ⁄* reset errno2 to zero *⁄
  *__err2ad() = 0x0;
  printf("__errno2 = %08x\n", __errno2());
 
  f = fopen("testfile.dat", "r");
  if (f == NULL){
    perror("fopen() failed");
    printf("__errno2 = %08x\n", __errno2());
  }
  
  return 0;
}