《unix环境高级编程》--- 公共部分

源码下载：http://apuebook.com/code3e.html

apue.3e/systype.h ：判断操作系统类别
apue.3e/Make.defines.linux：平台相关的定义
apue.3e/Make.libapue.inc：执行 “apue/lib/”中Makefile

apue.3e/include/apue.h：宏定义和函数声明
apue.3e/lib/：函数的具体实现

父文件夹

systype.sh
判断操作系统类别

# (leading space required for Xenix /bin/sh)

#
# Determine the type of *ix operating system that we're
# running on, and echo an appropriate value.
# This script is intended to be used in Makefiles.
# (This is a kludge.  Gotta be a better way.)
#
# 判断操作系统类别
case "`uname -s`" in
"FreeBSD")
    PLATFORM="freebsd"
    ;;
"Linux")
    PLATFORM="linux"
    ;;
"Darwin")
    PLATFORM="macos"
    ;;
"SunOS")
    PLATFORM="solaris"
    ;;
*)
    echo "Unknown platform" >&2
    exit 1
esac
echo $PLATFORM
exit 0

Make.defines.linux

# Common make definitions, customized for each platform

# Definitions required in all program directories to compile and link
# C programs using gcc.

# C语言编译器参数。默认命令是“cc”
CC = gcc

# CPPFLAGS: C++语言编译器参数
COMPILE.c = $(CC) $(CFLAGS) $(CPPFLAGS) -c

LINK.c = $(CC) $(CFLAGS) $(CPPFLAGS) $(LDFLAGS)

# LDFLAGS: 连接器参数（如“ld”）
LDFLAGS =

LDDIR = -L$(ROOT)/lib
LDLIBS = $(LDDIR) -lapue $(EXTRALIBS)

# -ansi ansi C标准
# -I将后面表示的目录作为第一个寻找头文件的目录，顺序为：(ROOT)/include->/usr/include->/usr/local/include
CFLAGS = -ansi -I$(ROOT)/include -Wall -DLINUX -D_GNU_SOURCE $(EXTRA)

RANLIB = echo

# 函数库打开包程序。默认命令是“ar”
AR = ar

AWK = awk
LIBAPUE = $(ROOT)/lib/libapue.a

# Common temp files to delete from each directory.
TEMPFILES = core core.* *.o temp.* *.out

Make.libapue.inc

$(LIBAPUE):
    (cd $(ROOT)/lib && $(MAKE))

---

子文件夹 include
apue.h

/*
 * 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 */

#define MAXLINE 4096        /* max line length */

/*
 * Default file access permissions for new files.
   用户读 | 用户写 | 用户组读 | 其他用户读
 */
#define FILE_MODE   (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)

/*
 * Default permissions for new directories.
   FILE_MODE | 用户执行 | 用户组执行 | 其他用户执行
 */
#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);

#endif  /* _APUE_H */

子文件夹 lib

Makefile

#
# Makefile for misc library.
#
ROOT=..
PLATFORM=$(shell $(ROOT)/systype.sh)
include $(ROOT)/Make.defines.$(PLATFORM)

LIBMISC = libapue.a
OBJS   = bufargs.o cliconn.o clrfl.o \
            daemonize.o error.o errorlog.o lockreg.o locktest.o \
            openmax.o pathalloc.o popen.o prexit.o prmask.o \
            ptyfork.o ptyopen.o readn.o recvfd.o senderr.o sendfd.o \
            servaccept.o servlisten.o setfd.o setfl.o signal.o signalintr.o \
            sleepus.o spipe.o tellwait.o ttymodes.o writen.o

all:    $(LIBMISC) sleep.o

$(LIBMISC):	$(OBJS)
    $(AR) rv $(LIBMISC) $?
    $(RANLIB) $(LIBMISC)


clean:
    rm -f *.o a.out core temp.* $(LIBMISC)

include $(ROOT)/Make.libapue.inc

error.c
输出至标准出错文件的出错处理函数

#include "apue.h"
#include <errno.h>      /* for definition of errno */
#include <stdarg.h>     /* ISO C variable aruments */

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;

    /*ap指向传入的第一个可选参数，fmt是最后一个确定的参数, 即...前面的参数*/   
    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);
}

/*
 * Nonfatal error unrelated to a system call.
 * Error code passed as explict parameter.
 * Print a message and return.
 */
void
err_cont(int error, const char *fmt, ...)
{
    va_list     ap;

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

/*
 * 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];

    /* int vsnprintf(char* str, size_t size, const char* format, va_list ap);
     * char *str [out],把生成的格式化的字符串存放在这里.
     * size_t size [in], str可接受的最大字符数
     * const char *format [in], 指定输出格式的字符串，它决定了你需要提供的可变参数的类型、个数和顺序
     * va_list ap [in], va_list变量. va:variable-argument:可变参数
     */
    vsnprintf(buf, MAXLINE-1, fmt, ap);
    if (errnoflag)
        snprintf(buf+strlen(buf), MAXLINE-strlen(buf)-1, ": %s",
          strerror(error));
    strcat(buf, "\n");
    fflush(stdout);     /* in case stdout and stderr are the same */
    fputs(buf, stderr);
    fflush(NULL);       /* flushes all stdio output streams */
}

errlog.c
用于守护进程的出错处理函数

/*
 * Error routines for programs that can run as a daemon.
 */

#include "apue.h"
#include <errno.h>      /* for definition of errno */
#include <stdarg.h>     /* ISO C variable arguments */
#include <syslog.h>

static void log_doit(int, int, int, const char *, va_list ap);

/*
 * Caller must define and set this: nonzero if
 * interactive, zero if daemon
 */
extern int  log_to_stderr;

/*
 * Initialize syslog(), if running as daemon.
 */
void
log_open(const char *ident, int option, int facility)
{
    if (log_to_stderr == 0)
        /* void openlog(const char *ident, int logopt, int facility);  
         * ident: 是一个字符串指针，它所指向的字符串会放在每个消息的前面，
         *        通常的应用都是设置为程序名，用来指示是哪个程序创建里这个消息
         * facility: 指定是什么程序类型在记录日志---这在后来使用 syslog() 里会被用到。
        */
        openlog(ident, option, facility);
}

/*
 * Nonfatal error related to a system call.
 * Print a message with the system's errno value and return.
 */
void
log_ret(const char *fmt, ...)
{
    va_list     ap;

    va_start(ap, fmt);
    log_doit(1, errno, LOG_ERR, fmt, ap);
    va_end(ap);
}

/*
 * Fatal error related to a system call.
 * Print a message and terminate.
 */
void
log_sys(const char *fmt, ...)
{
    va_list     ap;

    va_start(ap, fmt);
    log_doit(1, errno, LOG_ERR, fmt, ap);
    va_end(ap);
    exit(2);
}

/*
 * Nonfatal error unrelated to a system call.
 * Print a message and return.
 */
void
log_msg(const char *fmt, ...)
{
    va_list     ap;

    va_start(ap, fmt);
    log_doit(0, 0, LOG_ERR, fmt, ap);
    va_end(ap);
}

/*
 * Fatal error unrelated to a system call.
 * Print a message and terminate.
 */
void
log_quit(const char *fmt, ...)
{
    va_list     ap;

    va_start(ap, fmt);
    log_doit(0, 0, LOG_ERR, fmt, ap);
    va_end(ap);
    exit(2);
}

/*
 * Fatal error related to a system call.
 * Error number passed as an explicit parameter.
 * Print a message and terminate.
 */
void
log_exit(int error, const char *fmt, ...)
{
    va_list     ap;

    va_start(ap, fmt);
    log_doit(1, error, LOG_ERR, fmt, ap);
    va_end(ap);
    exit(2);
}

/*
 * Print a message and return to caller.
 * Caller specifies "errnoflag" and "priority".
 */
static void
log_doit(int errnoflag, int error, int priority, const char *fmt,
         va_list ap)
{
    char    buf[MAXLINE];

    vsnprintf(buf, MAXLINE-1, fmt, ap);
    if (errnoflag)
        snprintf(buf+strlen(buf), MAXLINE-strlen(buf)-1, ": %s",
          strerror(error));
    strcat(buf, "\n");
    if (log_to_stderr) {
        fflush(stdout);
        fputs(buf, stderr);
        fflush(stderr);
    } else {
        /* void syslog(int priority, const char *message, arguments...);  
         * 向日志设备(日志工具 facility)发送日志消息。每一个消息都有一个 priority(优先级) 参数，
         * 这个参数由一个“危险系数”(severity level)和一个程序标识码(facility value)相或(OR)得来。
         */
        syslog(priority, "%s", buf);
    }
}

其他的c文件未列出

执行make，可在lib文件下生成.o文件，libapue.a，

参考
http://www.bubuko.com/infodetail-1193969.html
https://www.cnblogs.com/xbf9xbf/p/4755458.html
https://www.cnblogs.com/yyangblog/p/4159778.html
https://blog.youkuaiyun.com/ixidof/article/details/5961621