真心不知到里面写的具体什么意思，先记下吧。
/*Our own header, to be included after all standard system headers*/
#ifndef __ourhdr_h
#define __ourhdr_h #include <errno.h> /*for definition of errno */
#include <stdarg.h> /*ANSI C header file */
#include <sys/types.h> /* required for some of our prototypes */
#include <stdio.h> /* for convenience */
#include <stdlib.h> /* for convenience */
#include <string.h> /* for convenience */
#include <unistd.h> /* for convenience */ #define MAXLINE 4096 /* max line length */
#define FILE_MODE (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)
/* default file access permissions for new files */
#define DIR_MODE (FILE_MODE | S_IXUSR | S_IXGRP | S_IXOTH)
/* default permissions for new directoris */
typedef void Sigfunc(int); /* for signal handlers */
/* 4.3BSD Reno <signal.h> doesn't define
SIG_ERR */
#if defined(SIG_IGN) && !defined(SIG_ERR)
#define SIG_ERR ((Sigfunc *)-1)
#endif
#define min(a,b) ((a) < (b) ? (a) : (b))
#define max(a,b) ((a) > (b) ? (a) : (b))
/* prototypes for our own functions */
char *path_alloc(int *); /* {Prog pathalloc} */
int open_max(void); /* {Prog openmax} */
void clr_fl(int, int); /* {Prog setfl} */
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} */
int tty_cbreak(int); /* {Prog raw} */
int tty_raw(int); /* {Prog raw} */
int tty_reset(int); /* {Prog raw} */
void tty_atexit(void); /* {Prog raw} */ #ifdef ECHO /* only if <termios.h> has been included */
struct termios *tty_termios(void); /* {Prog raw} */
#endif
void sleep_us(unsigned int); /* {Ex sleepus} */
ssize_t readn(int, void *, size_t); /* {Prog readn} */
ssize_t writen(int, const void *, size_t); /* {Prog writen} */
int daemon_init(void); /* {Prog daemoninit} */
int s_pipe(int *); /* {Progs svr4_spipe bsd spipe} */
int recv_fd(int, ssize_t (*func)(int, const void *, size_t));
/* {Prog recvfd_svr4 recvfd_43bsd} */ int send_fd(int, int); /* {Progs sendfd_svr4 se
dfd_43bsd} */
int send_err(int, int, const char *);/* {Prog senderr} */
int serv_listen(const char *); /* {Progs servlisten_svr4 servli
ten_4
4bsd} */
int serv_accept(int, uid_t *); /* {Progs servaccept_svr4 servac
ept_4
4bsd} */
int cli_conn(const char *); /* {Progs cliconn_svr4 cliconn_4
bsd} */
int buf_args(char *, int (*func)(int, char **));
/* {Prog bufargs} */
int ptym_open(char *); /* {Progs ptyopen_svr4 p yopen_44bsd} */
int ptys_open(int, char *); /* {Progs ptyopen_svr4 ptyopen_4 bsd} */ #ifdef TIOCGWINSZ
pid_t pty_fork(int *, char *, 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_readlock(fd, offset, whence, len) lock_test(fd, F_RDLCK, offset, whence, len)
#define is_writelock(fd, offset, whence, len) lock_test(fd, F_WRLCK, offset, whence, len)
void err_dump(const char *, ...); /* {App misc_source} */
void err_msg(const char *, ...);
void err_quit(const char *, ...);
void err_ret(const char *, ...);
void err_sys(const char *, ...);
void log_msg(const char *, ...); /* {App misc_source} */
void log_open(const char *, int, int);
void log_quit(const char *, ...);
void log_ret(const char *, ...);
void log_sys(const char *, ...);
void TELL_WAIT(void); /* parent/child from {Sec race_condition } */
void TELL_PARENT(pid_t);
void TELL_CHILD(pid_t);
void WAIT_PARENT(void);
void WAIT_CHILD(void);
#endif /* __ourhdr_h */ static void err_doit(int, const char*, va_list);
char *pname = NULL; /* caller can set this from argv[0]*/
/* Nonfatal error realated to a system call . print a message and return . */
void err_ret(const char *fmt,...)
{
va_list ap;
va_start(ap, fmt);
err_doit(, 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(, fmt, ap);
va_end(ap);
exit();
}
/* 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(, fmt, ap);
va_end(ap);
abort(); /* dump core and terminate */
exit(); /* shouldn't get here */
} /* Nofatal error related to a system call . print a message and return. */
void err_msg(const char *fmt,...)
{
va_list ap; va_start(ap, fmt);
err_doit(, fmt, ap);
va_end(ap); return;
}
/* Fatal error related to a system call . print a message and terminate. */
void err_quit(const char *fmt,...)
{
va_list ap;
va_start(ap, fmt);
err_doit(, fmt, ap);
va_end(ap);
exit();
}
/* 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(NULL); /*flushes and stdio output streams */ return;
}