ash.c

shell-HHARM9200.rar 华恒 AT91rm9200 中Busybox shell的源代码

/* vi: set sw=4 ts=4: */
/*
 * ash shell port for busybox
 *
 * Copyright (c) 1989, 1991, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * Copyright (c) 1997-2003 Herbert Xu <[e-mail]>
 * was re-ported from NetBSD and debianized.
 *
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Original BSD copyright notice is retained at the end of this file.
 */

/*
 * rewrite arith.y to micro stack based cryptic algorithm by
 * Copyright (c) 2001 Aaron Lehmann <[e-mail]>
 *
 * Modified by Paul Mundt <[e-mail]> (c) 2004 to support
 * dynamic variables.
 *
 * Modified by Vladimir Oleynik <[e-mail]> (c) 2001-2004 to be
 * used in busybox and size optimizations,
 * rewrote arith (see notes to this), added locale support,
 * rewrote dynamic variables.
 *
 */


/*
 * The follow should be set to reflect the type of system you have:
 *      JOBS -> 1 if you have Berkeley job control, 0 otherwise.
 *      define SYSV if you are running under System V.
 *      define DEBUG=1 to compile in debugging ('set -o debug' to turn on)
 *      define DEBUG=2 to compile in and turn on debugging.
 *
 * When debugging is on, debugging info will be written to ./trace and
 * a quit signal will generate a core dump.
 */



#define IFS_BROKEN

#define PROFILE 0

#ifdef DEBUG
#define _GNU_SOURCE
#endif

#include <sys/types.h>
#include <sys/cdefs.h>
#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/wait.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <stdarg.h>
#include <stddef.h>
#include <assert.h>
#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <paths.h>
#include <setjmp.h>
#include <signal.h>
#include <stdint.h>
#include <sysexits.h>
#include <time.h>
#include <fnmatch.h>


#include "busybox.h"
#include "pwd_.h"

#ifdef CONFIG_ASH_JOB_CONTROL
#define JOBS 1
#else
#undef JOBS
#endif

#if JOBS
#include <termios.h>
#endif

#include "cmdedit.h"

#ifdef __GLIBC__
/* glibc sucks */
static int *dash_errno;
#undef errno
#define errno (*dash_errno)
#endif

#if defined(__uClinux__)
#error "Do not even bother, ash will not run on uClinux"
#endif

#ifdef DEBUG
#define _DIAGASSERT(assert_expr) assert(assert_expr)
#else
#define _DIAGASSERT(assert_expr)
#endif


#ifdef CONFIG_ASH_ALIAS
/*      $NetBSD: alias.h,v 1.5 2002/11/24 22:35:38 christos Exp $       */

#define ALIASINUSE      1
#define ALIASDEAD       2

struct alias {
	struct alias *next;
	char *name;
	char *val;
	int flag;
};

static struct alias *lookupalias(const char *, int);
static int aliascmd(int, char **);
static int unaliascmd(int, char **);
static void rmaliases(void);
static int unalias(const char *);
static void printalias(const struct alias *);
#endif

/*      $NetBSD: cd.h,v 1.3 2002/11/24 22:35:39 christos Exp $  */


static void    setpwd(const char *, int);

/*      $NetBSD: error.h,v 1.15 2002/11/24 22:35:39 christos Exp $      */


/*
 * Types of operations (passed to the errmsg routine).
 */


static const char not_found_msg[] = "%s: not found";


#define E_OPEN  "No such file"          /* opening a file */
#define E_CREAT "Directory nonexistent" /* creating a file */
#define E_EXEC  not_found_msg+4         /* executing a program */

/*
 * We enclose jmp_buf in a structure so that we can declare pointers to
 * jump locations.  The global variable handler contains the location to
 * jump to when an exception occurs, and the global variable exception
 * contains a code identifying the exeception.  To implement nested
 * exception handlers, the user should save the value of handler on entry
 * to an inner scope, set handler to point to a jmploc structure for the
 * inner scope, and restore handler on exit from the scope.
 */

struct jmploc {
	jmp_buf loc;
};

static struct jmploc *handler;
static int exception;
static volatile int suppressint;
static volatile sig_atomic_t intpending;

static int exerrno;            /* Last exec error, error for EXEXEC */

/* exceptions */
#define EXINT 0         /* SIGINT received */
#define EXERROR 1       /* a generic error */
#define EXSHELLPROC 2   /* execute a shell procedure */
#define EXEXEC 3        /* command execution failed */
#define EXEXIT 4        /* exit the shell */
#define EXSIG 5         /* trapped signal in wait(1) */


/* do we generate EXSIG events */
static int exsig;
/* last pending signal */
static volatile sig_atomic_t pendingsigs;

/*
 * These macros allow the user to suspend the handling of interrupt signals
 * over a period of time.  This is similar to SIGHOLD to or sigblock, but
 * much more efficient and portable.  (But hacking the kernel is so much
 * more fun than worrying about efficiency and portability. :-))
 */

#define barrier() ({ __asm__ __volatile__ ("": : :"memory"); })
#define INTOFF \
	({ \
		suppressint++; \
		barrier(); \
		0; \
	})
#define SAVEINT(v) ((v) = suppressint)
#define RESTOREINT(v) \
	({ \
		barrier(); \
		if ((suppressint = (v)) == 0 && intpending) onint(); \
		0; \
	})
#define EXSIGON() \
	({ \
		exsig++; \
		barrier(); \
		if (pendingsigs) \
			exraise(EXSIG); \
		0; \
	})
/* EXSIG is turned off by evalbltin(). */


static void exraise(int) __attribute__((__noreturn__));
static void onint(void) __attribute__((__noreturn__));

static void error(const char *, ...) __attribute__((__noreturn__));
static void exerror(int, const char *, ...) __attribute__((__noreturn__));

static void sh_warnx(const char *, ...);

#ifdef CONFIG_ASH_OPTIMIZE_FOR_SIZE
static void
inton(void) {
	if (--suppressint == 0 && intpending) {
		onint();
	}
}
#define INTON inton()
static void forceinton(void)
{
	suppressint = 0;
	if (intpending)
		onint();
}
#define FORCEINTON forceinton()
#else
#define INTON \
	({ \
		barrier(); \
		if (--suppressint == 0 && intpending) onint(); \
		0; \
	})
#define FORCEINTON \
	({ \
		barrier(); \
		suppressint = 0; \
		if (intpending) onint(); \
		0; \
	})
#endif /* CONFIG_ASH_OPTIMIZE_FOR_SIZE */

/*
 * BSD setjmp saves the signal mask, which violates ANSI C and takes time,
 * so we use _setjmp instead.
 */

#if defined(BSD) && !defined(__SVR4) && !defined(__GLIBC__)
#define setjmp(jmploc)  _setjmp(jmploc)
#define longjmp(jmploc, val)    _longjmp(jmploc, val)
#endif

/*      $NetBSD: expand.h,v 1.13 2002/11/24 22:35:40 christos Exp $     */

struct strlist {
	struct strlist *next;
	char *text;
};


struct arglist {
	struct strlist *list;
	struct strlist **lastp;
};

/*
 * expandarg() flags
 */
#define EXP_FULL        0x1     /* perform word splitting & file globbing */
#define EXP_TILDE       0x2     /* do normal tilde expansion */
#define EXP_VARTILDE    0x4     /* expand tildes in an assignment */
#define EXP_REDIR       0x8     /* file glob for a redirection (1 match only) */
#define EXP_CASE        0x10    /* keeps quotes around for CASE pattern */
#define EXP_RECORD      0x20    /* need to record arguments for ifs breakup */
#define EXP_VARTILDE2   0x40    /* expand tildes after colons only */
#define EXP_WORD        0x80    /* expand word in parameter expansion */
#define EXP_QWORD       0x100   /* expand word in quoted parameter expansion */


union node;
static void expandarg(union node *, struct arglist *, int);
#define rmescapes(p) _rmescapes((p), 0)
static char *_rmescapes(char *, int);
static int casematch(union node *, char *);

#ifdef CONFIG_ASH_MATH_SUPPORT
static void expari(int);
#endif

/*      $NetBSD: eval.h,v 1.13 2002/11/24 22:35:39 christos Exp $       */

static char *commandname;              /* currently executing command */
static struct strlist *cmdenviron;     /* environment for builtin command */
static int exitstatus;                 /* exit status of last command */
static int back_exitstatus;            /* exit status of backquoted command */


struct backcmd {                /* result of evalbackcmd */
	int fd;                 /* file descriptor to read from */
	char *buf;              /* buffer */
	int nleft;              /* number of chars in buffer */
	struct job *jp;         /* job structure for command */
};

/*
 * This file was generated by the mknodes program.
 */

#define NCMD 0
#define NPIPE 1
#define NREDIR 2
#define NBACKGND 3
#define NSUBSHELL 4
#define NAND 5
#define NOR 6
#define NSEMI 7
#define NIF 8
#define NWHILE 9
#define NUNTIL 10
#define NFOR 11
#define NCASE 12
#define NCLIST 13
#define NDEFUN 14
#define NARG 15
#define NTO 16
#define NCLOBBER 17
#define NFROM 18
#define NFROMTO 19
#define NAPPEND 20
#define NTOFD 21
#define NFROMFD 22
#define NHERE 23
#define NXHERE 24
#define NNOT 25



struct ncmd {
      int type;
      union node *assign;
      union node *args;
      union node *redirect;
};


struct npipe {
      int type;
      int backgnd;
      struct nodelist *cmdlist;
};


struct nredir {
      int type;
      union node *n;
      union node *redirect;
};


struct nbinary {
      int type;
      union node *ch1;
      union node *ch2;
};


struct nif {
      int type;
      union node *test;
      union node *ifpart;
      union node *elsepart;
};


struct nfor {
      int type;
      union node *args;
      union node *body;
      char *var;
};


struct ncase {
      int type;
      union node *expr;
      union node *cases;
};


struct nclist {
      int type;
      union node *next;
      union node *pattern;
      union node *body;
};


struct narg {
      int type;
      union node *next;
      char *text;
      struct nodelist *backquote;
};


struct nfile {
      int type;
      union node *next;
      int fd;
      union node *fname;
      char *expfname;
};


struct ndup {
      int type;
      union node *next;
      int fd;
      int dupfd;
      union node *vname;