Generically speaking, cover functions

I'm tired of writing this: 

ptr = malloc (sizeof (*ptr));
if (ptr == NULL) {
    fprintf (stderr, "%s:  unable to malloc() %d bytes, errno %d (%s)\n",
             progname, sizeof (*ptr), errno, strerror (errno));
    // and optionally writing it to syslog() too
    exit (EXIT_FAILURE);
}

Over, and over, and over again. So, I wrote a little macro cover function: 

#define emalloc(n)  emallocWORKER (n,__LINE__,__FILE__);
extern  void        *emallocWORKER (size_t size, int lineNumber, const char *sourceFile);

And then the actual function itself: 

extern  char *progname;                     /* defined by user */

void *
emallocWORKER (size_t size, int lineNumber, const char *sourceFile)
{
    void    *ptr;

    fatal (!(ptr = malloc (size)), "unable to allocate %d bytes (module %s, line %d)\n",
           progname, size, sourceFile, lineNumber);
    return (ptr);
}

It's damn useful to put in the __FILE__ and __LINE__ manifests!

Others

I do the same thing for ecalloc(), erealloc(), eopen(), efopen(), etc. Whenever I find myself doing a check against a success and then printing a message and exiting is a good candidate for this.