C/C++ Exit Codes（错误码）

#define EX_OK           0       /* successful termination */
#define EX__BASE        64      /* base value for error messages */
#define EX_USAGE        64      /* command line usage error */
#define EX_DATAERR      65      /* data format error */
#define EX_NOINPUT      66      /* cannot open input */    
#define EX_NOUSER       67      /* addressee unknown */    
#define EX_NOHOST       68      /* host name unknown */
#define EX_UNAVAILABLE  69      /* service unavailable */
#define EX_SOFTWARE     70      /* internal software error */
#define EX_OSERR        71      /* system error (e.g., can't fork) */
#define EX_OSFILE       72      /* critical OS file missing */
#define EX_CANTCREAT    73      /* can't create (user) output file */
#define EX_IOERR        74      /* input/output error */
#define EX_TEMPFAIL     75      /* temp failure; user is invited to retry */
#define EX_PROTOCOL     76      /* remote error in protocol */
#define EX_NOPERM       77      /* permission denied */
#define EX_CONFIG       78      /* configuration error */
 
#define EX__MAX 78      /* maximum listed value */

实例

#include <stdio.h>
#include <sysexits.h>

#define ONE_BUF_GROWN		1024000

data_buf = (char*) malloc ( ONE_BUF_GROWN );
if(!data_buf) {
    //printf("malloc data_buf fail!\n");
	syslog ( LOG_ERR, "malloc data_buf fail!\n" );
	return EX_OSERR;
}