sh.h

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

/*
 * Public Domain Bourne/Korn shell
 */

/* $Id: sh.h,v 1.2 1994/05/19 18:32:40 michael Exp michael $ */

#include "config.h"	/* system and option configuration info */

#ifdef HAVE_PROTOTYPES
# define	ARGS(args)	args	/* prototype declaration */
#else
# define	ARGS(args)	()	/* K&R declaration */
#endif


/* Start of common headers */

#include <stdio.h>
#include <sys/types.h>
#include <setjmp.h>
#ifdef HAVE_STDDEF_H
# include <stddef.h>
#endif

#ifdef HAVE_STDLIB_H
# include <stdlib.h>
#else
/* just a useful subset of what stdlib.h would have */
extern char * getenv  ARGS((const char *));
extern void * malloc  ARGS((size_t));
extern void * realloc ARGS((void *, size_t));
extern int    free    ARGS((void *));
extern int    exit    ARGS((int));
extern int    rand    ARGS((void));
extern void   srand   ARGS((unsigned int));
extern int    atoi    ARGS((const char *));
#endif /* HAVE_STDLIB_H */

#ifdef HAVE_UNISTD_H
# include <unistd.h>
#else
/* just a useful subset of what unistd.h would have */
extern int access ARGS((const char *, int));
extern int open ARGS((const char *, int, ...));
extern int creat ARGS((const char *, mode_t));
extern int read ARGS((int, char *, unsigned));
extern int write ARGS((int, const char *, unsigned));
extern off_t lseek ARGS((int, off_t, int));
extern int close ARGS((int));
extern int pipe ARGS((int []));
extern int dup2 ARGS((int, int));
extern int unlink ARGS((const char *));
extern int fork ARGS((void));
extern int execve ARGS((const char *, char * const[], char * const[]));
extern int chdir ARGS((const char *));
extern int kill ARGS((pid_t, int));
extern char *getcwd();	/* no ARGS here - differs on different machines */
extern int geteuid ARGS((void));
extern int readlink ARGS((const char *, char *, int));
extern int getegid ARGS((void));
extern int getpid ARGS((void));
extern int getppid ARGS((void));
extern unsigned int sleep ARGS((unsigned int));
extern int isatty ARGS((int));
# ifdef POSIX_PGRP
extern int getpgrp ARGS((void));
extern int setpgid ARGS((pid_t, pid_t));
# endif /* POSIX_PGRP */
# ifdef BSD_PGRP
extern int getpgrp ARGS((pid_t));
extern int setpgrp ARGS((pid_t, pid_t));
# endif /* BSD_PGRP */
# ifdef SYSV_PGRP
extern int getpgrp ARGS((void));
extern int setpgrp ARGS((void));
# endif /* SYSV_PGRP */
#endif /* HAVE_UNISTD_H */

#ifdef HAVE_STRING_H
# include <string.h>
#else
# include <strings.h>
# define strchr index
# define strrchr rindex
#endif /* HAVE_STRING_H */
#ifndef HAVE_STRSTR
char *strstr ARGS((const char *s, const char *p));
#endif /* HAVE_STRSTR */
#ifndef HAVE_STRCASECMP
int strcasecmp ARGS((const char *s1, const char *s2));
int strncasecmp ARGS((const char *s1, const char *s2, int n));
#endif /* HAVE_STRCASECMP */

#ifdef HAVE_MEMORY_H
# include <memory.h>
#endif
#ifndef HAVE_MEMSET
# define memcpy(d, s, n)	bcopy(s, d, n)
# define memcmp(s1, s2, n)	bcmp(s1, s2, n)
void *memset ARGS((void *d, int c, size_t n));
#endif /* HAVE_MEMSET */
#ifndef HAVE_MEMMOVE
# ifdef HAVE_BCOPY
#  define memmove(d, s, n)	bcopy(s, d, n)
# else
void *memmove ARGS((void *d, const void *s, size_t n));
# endif
#endif /* HAVE_MEMMOVE */

#ifdef HAVE_PROTOTYPES
# include <stdarg.h>
# define SH_VA_START(va, argn) va_start(va, argn)
#else
# include <varargs.h>
# define SH_VA_START(va, argn) va_start(va)
#endif /* HAVE_PROTOTYPES */

#include <errno.h>
extern int errno;

#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#else
# include <sys/file.h>
#endif /* HAVE_FCNTL_H */
#ifndef O_ACCMODE
# define O_ACCMODE	(O_RDONLY|O_WRONLY|O_RDWR)
#endif /* !O_ACCMODE */

#ifndef F_OK 	/* access() arguments */
# define F_OK 0
# define X_OK 1
# define W_OK 2
# define R_OK 4
#endif /* !F_OK */

#ifndef SEEK_SET
# ifdef L_SET
#  define SEEK_SET L_SET
#  define SEEK_CUR L_INCR
#  define SEEK_END L_XTND
# else /* L_SET */
#  define SEEK_SET 0
#  define SEEK_CUR 1
#  define SEEK_END 2
# endif /* L_SET */
#endif /* !SEEK_SET */

/* Some machines (eg, FreeBSD 1.1.5) define CLK_TCK in limits.h
 * (ksh_limval.h assumes limits has been included, if available)
 */
#ifdef HAVE_LIMITS_H
# include <limits.h>
#endif /* HAVE_LIMITS_H */

#include <signal.h>
#ifdef	NSIG
# define SIGNALS	NSIG
#else
# ifdef	_MINIX
#  define SIGNALS	(_NSIG+1) /* _NSIG is # of signals used, excluding 0. */
# else
#  ifdef _SIGMAX	/* QNX */
#   define SIGNALS	_SIGMAX
#  else /* _SIGMAX */
#   define SIGNALS	32
#  endif /* _SIGMAX */
# endif	/* _MINIX */
#endif	/* NSIG */
#ifndef SIGCHLD
# define SIGCHLD SIGCLD
#endif
/* struct sigaction.sa_flags is set to KSH_SA_FLAGS.  Used to ensure
 * system calls are interrupted
 */
#ifdef SA_INTERRUPT
# define KSH_SA_FLAGS	SA_INTERRUPT
#else /* SA_INTERRUPT */
# define KSH_SA_FLAGS	0
#endif /* SA_INTERRUPT */

typedef	RETSIGTYPE (*handler_t) ARGS((int));	/* signal handler */

#ifdef USE_FAKE_SIGACT
# include "sigact.h"			/* use sjg's fake sigaction() */
#endif

#ifdef HAVE_PATHS_H
# include <paths.h>
#endif /* HAVE_PATHS_H */
#ifdef _PATH_DEFPATH
# define DEFAULT__PATH _PATH_DEFPATH
#else /* _PATH_DEFPATH */
# define DEFAULT__PATH DEFAULT_PATH
#endif /* _PATH_DEFPATH */

#ifndef offsetof
# define offsetof(type,id) ((size_t)&((type*)NULL)->id)
#endif

#ifndef HAVE_KILLPG
# define killpg(p, s)	kill(-(p), (s))
#endif /* !HAVE_KILLPG */

/* Special cases for execve(2) */
#ifdef OS2
extern int ksh_execve(char *cmd, char **args, char **env, int flags);
#else /* OS2 */
# if defined(OS_ISC) && defined(_POSIX_SOURCE)
/* Kludge for ISC 3.2 (and other versions?) so programs will run correctly.  */
#  define ksh_execve(p, av, ev, flags) \
				do { \
					__setostype(0); \
					execve(p, av, ev); \
					__setostype(1); \
				} while (0)
# else /* OS_ISC && _POSIX */
#  define ksh_execve(p, av, ev, flags)	execve(p, av, ev)
# endif /* OS_ISC && _POSIX */
#endif /* OS2 */

/* this is a hang-over from older versions of the os2 port */
#define ksh_dupbase(fd, base) fcntl(fd, F_DUPFD, base)

#ifdef HAVE_SIGSETJMP
# define ksh_sigsetjmp(env,sm)	sigsetjmp((env), (sm))
# define ksh_siglongjmp(env,v)	siglongjmp((env), (v))
# define ksh_jmp_buf		sigjmp_buf
#else /* HAVE_SIGSETJMP */
# ifdef HAVE__SETJMP
#  define ksh_sigsetjmp(env,sm)	_setjmp(env)
#  define ksh_siglongjmp(env,v)	_longjmp((env), (v))
# else /* HAVE__SETJMP */
#  define ksh_sigsetjmp(env,sm)	setjmp(env)
#  define ksh_siglongjmp(env,v)	longjmp((env), (v))
# endif /* HAVE__SETJMP */
# define ksh_jmp_buf		jmp_buf
#endif /* HAVE_SIGSETJMP */

#ifndef HAVE_DUP2
extern int dup2 ARGS((int, int));
#endif /* !HAVE_DUP2 */

/* Find a integer type that is at least 32 bits (or die) - SIZEOF_* defined
 * by autoconf (assumes an 8 bit byte, but I'm not concerned).
 * NOTE: INT32 may end up being more than 32 bits.
 */
#ifdef __OLD__
#if SIZEOF_INT >= 4
# define INT32	long
/* #else SIZEOF_INT */
# if SIZEOF_LONG >= 4
#  define INT32	long
# else /* SIZEOF_LONG */
   #error cannot find 32 bit type...
# endif /* SIZEOF_LONG */
#endif /* SIZEOF_INT */
#endif

#define INT32 long

/* end of common headers */

/* Stop gcc and lint from complaining about possibly uninitialized variables */
#if defined(__GNUC__) || defined(lint)
# define UNINITIALIZED(var)	var = 0
#else
# define UNINITIALIZED(var)	var
#endif /* GNUC || lint */

/* some useful #defines */
#ifdef EXTERN
# define I__(i) = i
#else
# define I__(i)
# define EXTERN extern
# define EXTERN_DEFINED
#endif

#ifdef OS2
# define inDOS() (!(_emx_env & 0x200))
#endif

#ifndef EXECSHELL
/* shell to exec scripts (see also $SHELL initialization in main.c) */
# ifdef OS2
#  define EXECSHELL	(inDOS() ? "c:\\command.com" : "c:\\os2\\cmd.exe")
#  define EXECSHELL_STR	(inDOS() ? "COMSPEC" : "OS2_SHELL")
# else /* OS2 */
#  define EXECSHELL	"/bin/sh"
#  define EXECSHELL_STR	"EXECSHELL"
# endif /* OS2 */
#endif

/* ISABSPATH() means path is fully and completely specified,
 * ISROOTEDPATH() means a .. as the first component is a no-op,
 * ISRELPATH() means $PWD can be tacked on to get an absolute path.
 *
 * OS		Path		ISABSPATH	ISROOTEDPATH	ISRELPATH
 * unix		/foo		yes		yes		no
 * unix		foo		no		no		yes
 * unix		../foo		no		no		yes
 * os2+cyg	a:/foo		yes		yes		no
 * os2+cyg	a:foo		no		no		no
 * os2+cyg	/foo		no		yes		no
 * os2+cyg	foo		no		no		yes
 * os2+cyg	../foo		no		no		yes
 * cyg 		//foo		yes		yes		no
 */
#ifdef OS2
# define PATHSEP        ';'
# define DIRSEP         '/'	/* even though \ is native */
# define DIRSEPSTR      "\\"
# define ISDIRSEP(c)    ((c) == '\\' || (c) == '/')
# define ISABSPATH(s)	(((s)[0] && (s)[1] == ':' && ISDIRSEP((s)[2])))
# define ISROOTEDPATH(s) (ISDIRSEP((s)[0]) || ISABSPATH(s))
# define ISRELPATH(s)	(!(s)[0] || ((s)[1] != ':' && !ISDIRSEP((s)[0])))
# define FILECHCONV(c)	(isascii(c) && isupper(c) ? tolower(c) : c)
# define FILECMP(s1, s2) stricmp(s1, s2)
# define FILENCMP(s1, s2, n) strnicmp(s1, s2, n)
extern char *ksh_strchr_dirsep(const char *path);
extern char *ksh_strrchr_dirsep(const char *path);
# define chdir          _chdir2
# define getcwd         _getcwd2
#else
# define PATHSEP        ':'
# define DIRSEP         '/'
# define DIRSEPSTR      "/"
# define ISDIRSEP(c)    ((c) == '/')
#ifdef __CYGWIN__
#  define ISABSPATH(s) \
       (((s)[0] && (s)[1] == ':' && ISDIRSEP((s)[2])) || ISDIRSEP((s)[0]))
#  define ISRELPATH(s) (!(s)[0] || ((s)[1] != ':' && !ISDIRSEP((s)[0])))
#else /* __CYGWIN__ */
# define ISABSPATH(s)	ISDIRSEP((s)[0])
# define ISRELPATH(s)	(!ISABSPATH(s))
#endif /* __CYGWIN__ */
# define ISROOTEDPATH(s) ISABSPATH(s)
# define FILECHCONV(c)	c
# define FILECMP(s1, s2) strcmp(s1, s2)
# define FILENCMP(s1, s2, n) strncmp(s1, s2, n)
# define ksh_strchr_dirsep(p)   strchr(p, DIRSEP)
# define ksh_strrchr_dirsep(p)  strrchr(p, DIRSEP)
#endif

typedef int bool_t;
#define	FALSE	0
#define	TRUE	1

#define	NELEM(a) (sizeof(a) / sizeof((a)[0]))
#define	sizeofN(type, n) (sizeof(type) * (n))
#define	BIT(i)	(1<<(i))	/* define bit in flag */

/* Table flag type - needs > 16 and < 32 bits */
typedef INT32 Tflag;

#define	NUFILE	10		/* Number of user-accessible files */
#define	FDBASE	10		/* First file usable by Shell */

/* you're not going to run setuid shell scripts, are you? */
#define	eaccess(path, mode)	access(path, mode)

/* Make MAGIC a char that might be printed to make bugs more obvious, but
 * not a char that is used often.  Also, can't use the high bit as it causes
 * portability problems (calling strchr(x, 0x80|'x') is error prone).
 */
#define	MAGIC		(7)/* prefix for *?[!{,} during expand */
#define ISMAGIC(c)	((unsigned char)(c) == MAGIC)
#define	NOT		'!'	/* might use ^ (ie, [!...] vs [^..]) */

#define	LINE	1024		/* input line size */
#define	PATH	1024		/* pathname size (todo: PATH_MAX/pathconf()) */
#define ARRAYMAX 1023		/* max array index */

EXTERN	const char *kshname;	/* $0 */