錯誤信息：

: undefined reference to `err_quit‘
: undefined reference to `err_sys‘

解決方法：

因為err_quit跟err_sys是作者自己定義的錯誤處理函數。所以最簡單的解決辦法是修改下apue.h文件，如下

/*
 * Our own header, to be included before all standard system headers.
 */
#ifndef    _APUE_H
#define    _APUE_H

#define _POSIX_C_SOURCE 200809L

#if defined(SOLARIS)        /* Solaris 10 */
#define
 
 _XOPEN_SOURCE 600
#else
#define _XOPEN_SOURCE 700
#endif

#include <sys/types.h>        /* some systems still require this */
#include <sys/stat.h>
#include <sys/termios.h>    /* for winsize */
#if defined(MACOS) || !defined(TIOCGWINSZ)
#include <sys/ioctl.h>
#endif

#include <stdio.h>        /*
 
 for convenience */
#include <stdlib.h>        /* for convenience */
#include <stddef.h>        /* for offsetof */
#include <string.h>        /* for convenience */
#include <unistd.h>        /* for convenience */
#include <signal.h>        /* for SIG_ERR */
#include <errno.h>
#include 
 
<stdarg.h>

#define    MAXLINE    4096            /* max line length */

/*
 * Default file access permissions for new files.
 */
#define    FILE_MODE    (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)

/*
 * Default permissions for new directories.
 */
#define    DIR_MODE    (FILE_MODE | S_IXUSR | S_IXGRP | S_IXOTH)

typedef    void    Sigfunc(int);    /* for signal handlers */

#define    min(a,b)    ((a) < (b) ? (a) : (b))
#define    max(a,b)    ((a) > (b) ? (a) : (b))

/*
 * Prototypes for our own functions.
 */
char    *path_alloc(size_t *);                /* {Prog pathalloc} */
long     open_max(void);                    /* {Prog openmax} */

int         set_cloexec(int);                    /* {Prog setfd} */
void     clr_fl(int, int);
void     set_fl(int, int);                    /* {Prog setfl} */

void     pr_exit(int);                        /* {Prog prexit} */

void     pr_mask(const char *);                /* {Prog prmask} */
Sigfunc    *signal_intr(int, Sigfunc *);        /* {Prog signal_intr_function} */

void     daemonize(const char *);            /* {Prog daemoninit} */

void     sleep_us(unsigned int);            /* {Ex sleepus} */
ssize_t     readn(int, void *, size_t);        /* {Prog readn_writen} */
ssize_t     writen(int, const void *, size_t);    /* {Prog readn_writen} */

int         fd_pipe(int *);                    /* {Prog sock_fdpipe} */
int         recv_fd(int, ssize_t (*func)(int,
                 const void *, size_t));    /* {Prog recvfd_sockets} */
int         send_fd(int, int);                    /* {Prog sendfd_sockets} */
int         send_err(int, int,
                  const char *);            /* {Prog senderr} */
int         serv_listen(const char *);            /* {Prog servlisten_sockets} */
int         serv_accept(int, uid_t *);            /* {Prog servaccept_sockets} */
int         cli_conn(const char *);            /* {Prog cliconn_sockets} */
int         buf_args(char *, int (*func)(int,
                  char **));                /* {Prog bufargs} */

int         tty_cbreak(int);                    /* {Prog raw} */
int         tty_raw(int);                        /* {Prog raw} */
int         tty_reset(int);                    /* {Prog raw} */
void     tty_atexit(void);                    /* {Prog raw} */
struct termios    *tty_termios(void);            /* {Prog raw} */

int         ptym_open(char *, int);            /* {Prog ptyopen} */
int         ptys_open(char *);                    /* {Prog ptyopen} */
#ifdef    TIOCGWINSZ
pid_t     pty_fork(int *, char *, int, const struct termios *,
                  const struct winsize *);    /* {Prog ptyfork} */
#endif

int        lock_reg(int, int, int, off_t, int, off_t); /* {Prog lockreg} */

#define    read_lock(fd, offset, whence, len) \
            lock_reg((fd), F_SETLK, F_RDLCK, (offset), (whence), (len))
#define    readw_lock(fd, offset, whence, len) \
            lock_reg((fd), F_SETLKW, F_RDLCK, (offset), (whence), (len))
#define    write_lock(fd, offset, whence, len) \
            lock_reg((fd), F_SETLK, F_WRLCK, (offset), (whence), (len))
#define    writew_lock(fd, offset, whence, len) \
            lock_reg((fd), F_SETLKW, F_WRLCK, (offset), (whence), (len))
#define    un_lock(fd, offset, whence, len) \
            lock_reg((fd), F_SETLK, F_UNLCK, (offset), (whence), (len))

pid_t    lock_test(int, int, off_t, int, off_t);        /* {Prog locktest} */

#define    is_read_lockable(fd, offset, whence, len) \
            (lock_test((fd), F_RDLCK, (offset), (whence), (len)) == 0)
#define    is_write_lockable(fd, offset, whence, len) \
            (lock_test((fd), F_WRLCK, (offset), (whence), (len)) == 0)

void    err_msg(const char *, ...);            /* {App misc_source} */
void    err_dump(const char *, ...) __attribute__((noreturn));
void    err_quit(const char *, ...) __attribute__((noreturn));
void    err_cont(int, const char *, ...);
void    err_exit(int, const char *, ...) __attribute__((noreturn));
void    err_ret(const char *, ...);
void    err_sys(const char *, ...) __attribute__((noreturn));

void    log_msg(const char *, ...);            /* {App misc_source} */
void    log_open(const char *, int, int);
void    log_quit(const char *, ...) __attribute__((noreturn));
void    log_ret(const char *, ...);
void    log_sys(const char *, ...) __attribute__((noreturn));
void    log_exit(int, const char *, ...) __attribute__((noreturn));

void    TELL_WAIT(void);        /* parent/child from {Sec race_conditions} */
void    TELL_PARENT(pid_t);
void    TELL_CHILD(pid_t);
void    WAIT_PARENT(void);
void    WAIT_CHILD(void);


static void err_doit(int, int, const char *, va_list);  
  
/*  
 *  * 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, errno, fmt, ap);  
        va_end(ap);  
}  
  
/*  
 *  * 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, errno, fmt, ap);  
        va_end(ap);  
        exit(1);  
}  
  
/*  
 *  * Fatal error unrelated to a system call.  
 *  * Error code passed as explict parameter.  
 *  * Print a message and terminate.  
 *  */  
void  
err_exit(int error, const char *fmt, ...)  
{  
        va_list     ap;  
          
        va_start(ap, fmt);  
        err_doit(1, error, 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, errno, 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, 0, fmt, ap);  
        va_end(ap);  
}  
  
/*  
 *  * 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, 0, fmt, ap);  
        va_end(ap);  
        exit(1);  
}  
  
/*  
 *  * Print a message and return to caller.  
 *  * Caller specifies "errnoflag".  
 *  */  
static void  
err_doit(int errnoflag, int error, const char *fmt, va_list ap)  
{  
        char    buf[MAXLINE];  
        vsnprintf(buf, MAXLINE, fmt, ap);  
        if (errnoflag)  
        snprintf(buf+strlen(buf), MAXLINE-strlen(buf), ": %s",strerror(error));  
        strcat(buf, " ");  
        fflush(stdout);     /* in case stdout and stderr are the same */  
        fputs(buf, stderr);  
        fflush(NULL);       /* flushes all stdio output streams */  
}


#endif    /* _APUE_H */

Linux下運行《UNIX環境高級編程》undefined reference to `err_quit 編譯出錯的處理方法