error.c

unix环境高级编程的源代码

#include    <errno.h>        /* for definition of errno */
#include    <stdarg.h>        /* ANSI C header file */
#include    "ourhdr.h"

static void    err_doit(int, const char *, va_list);

char    *pname = NULL;        /* caller can set this from argv[0] */

/* Nonfatal error related to a system call.
 * Print a message and return. */

void
err_ret(const char *fmt, ...)
{
    va_list        ap;

    va_start(ap, fmt);
    err_doit(1, fmt, ap);
    va_end(ap);
    return;
}

/* Fatal error related to a system call.
 * Print a message and terminate. */

void
err_sys(const char *fmt, ...)
{
    va_list        ap;

    va_start(ap, fmt);
    err_doit(1, fmt, ap);
    va_end(ap);
    exit(1);
}

/* Fatal error related to a system call.
 * Print a message, dump core, and terminate. */

void
err_dump(const char *fmt, ...)
{
    va_list        ap;

    va_start(ap, fmt);
    err_doit(1, fmt, ap);
    va_end(ap);
    abort();        /* dump core and terminate */
    exit(1);        /* shouldn't get here */
}

/* Nonfatal error unrelated to a system call.
 * Print a message and return. */

void
err_msg(const char *fmt, ...)
{
    va_list        ap;

    va_start(ap, fmt);
    err_doit(0, fmt, ap);
    va_end(ap);
    return;
}

/* Fatal error unrelated to a system call.
 * Print a message and terminate. */

void
err_quit(const char *fmt, ...)
{
    va_list        ap;

    va_start(ap, fmt);
    err_doit(0, fmt, ap);
    va_end(ap);
    exit(1);
}

/* Print a message and return to caller.
 * Caller specifies "errnoflag". */

static void
err_doit(int errnoflag, const char *fmt, va_list ap)
{
    int        errno_save;
    char    buf[MAXLINE];

    errno_save = errno;        /* value caller might want printed */
    vsprintf(buf, fmt, ap);
    if (errnoflag)
        sprintf(buf+strlen(buf), ": %s", strerror(errno_save));
    strcat(buf, "\n");
    fflush(stdout);        /* in case stdout and stderr are the same */
    fputs(buf, stderr);
    fflush(stderr);        /* SunOS 4.1.* doesn't grok NULL argument */
    return;
}