explain_setenv_or_die - change or add an environment variable and report errors

       libexplain version 1.4
       Copyright (C) 2010 Peter Miller

                                                                                        explain_setenv_or_die(3)

       The  explain_setenv_or_die  function is used to call the setenv(3) system call. On failure an explanation
       will be printed to stderr, obtained from the explain_setenv(3) function, and then the process  terminates
       by calling exit(EXIT_FAILURE).

       The explain_setenv_on_error function is used to call the setenv(3) system call. On failure an explanation
       will be printed to stderr, obtained from the explain_setenv(3) function, but still returns to the caller.

       name    The name, exactly as to be passed to the setenv(3) system call.

       value   The value, exactly as to be passed to the setenv(3) system call.

       overwrite
               The overwrite, exactly as to be passed to the setenv(3) system call.

       The explain_setenv_or_die function is intended to be used in a fashion similar to the following example:
              explain_setenv_or_die(name, value, overwrite);

       explain_setenv_or_die - change or add an environment variable and report errors

       The  explain_setenv_or_die  function  only  returns  on  success,  see setenv(3) for more information. On
       failure, prints an explanation and exits, it does not return.

       The explain_setenv_on_error function always returns the value return  by  the  wrapped  setenv(3)  system
       call.

setenv(3)
               change or add an environment variable

       explain_setenv(3)
               explain setenv(3) errors

       exit(2) terminate the calling process

       #include <libexplain/setenv.h>
       void explain_setenv_or_die(const char *name, const char *value, int overwrite);
       int explain_setenv_on_error(const char *name, const char *value, int overwrite);