ash.c

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

#ifdef CONFIG_ASH_CMDCMD
	{ BUILTIN_REGULAR       "command", commandcmd },
#endif
	{ BUILTIN_SPEC_REG      "continue", breakcmd },
	{ BUILTIN_SPEC_REG      "eval", evalcmd },
	{ BUILTIN_SPEC_REG      "exec", execcmd },
	{ BUILTIN_SPEC_REG      "exit", exitcmd },
	{ BUILTIN_SPEC_REG_ASSG "export", exportcmd },
	{ BUILTIN_REGULAR       "false", falsecmd },
#ifdef JOBS
	{ BUILTIN_REGULAR       "fg", fgcmd },
#endif
#ifdef CONFIG_ASH_GETOPTS
	{ BUILTIN_REGULAR       "getopts", getoptscmd },
#endif
	{ BUILTIN_NOSPEC        "hash", hashcmd },
#ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
	{ BUILTIN_NOSPEC        "help", helpcmd },
#endif
#ifdef JOBS
	{ BUILTIN_REGULAR       "jobs", jobscmd },
	{ BUILTIN_REGULAR       "kill", killcmd },
#endif
#ifdef CONFIG_ASH_MATH_SUPPORT
	{ BUILTIN_NOSPEC        "let", letcmd },
#endif
	{ BUILTIN_ASSIGN        "local", localcmd },
	{ BUILTIN_NOSPEC        "pwd", pwdcmd },
	{ BUILTIN_REGULAR       "read", readcmd },
	{ BUILTIN_SPEC_REG_ASSG "readonly", exportcmd },
	{ BUILTIN_SPEC_REG      "return", returncmd },
	{ BUILTIN_SPEC_REG      "set", setcmd },
	{ BUILTIN_SPEC_REG      "shift", shiftcmd },
	{ BUILTIN_SPEC_REG      "times", timescmd },
	{ BUILTIN_SPEC_REG      "trap", trapcmd },
	{ BUILTIN_REGULAR       "true", truecmd },
	{ BUILTIN_NOSPEC        "type", typecmd },
	{ BUILTIN_NOSPEC        "ulimit", ulimitcmd },
	{ BUILTIN_REGULAR       "umask", umaskcmd },
#ifdef CONFIG_ASH_ALIAS
	{ BUILTIN_REGULAR       "unalias", unaliascmd },
#endif
	{ BUILTIN_SPEC_REG      "unset", unsetcmd },
	{ BUILTIN_REGULAR       "wait", waitcmd },
};

#define NUMBUILTINS  (sizeof (builtincmd) / sizeof (struct builtincmd) )



struct cmdentry {
	int cmdtype;
	union param {
		int index;
		const struct builtincmd *cmd;
		struct funcnode *func;
	} u;
};


/* action to find_command() */
#define DO_ERR          0x01    /* prints errors */
#define DO_ABS          0x02    /* checks absolute paths */
#define DO_NOFUNC       0x04    /* don't return shell functions, for command */
#define DO_ALTPATH      0x08    /* using alternate path */
#define DO_ALTBLTIN     0x20    /* %builtin in alt. path */

static const char *pathopt;     /* set by padvance */

static void shellexec(char **, const char *, int)
    __attribute__((__noreturn__));
static char *padvance(const char **, const char *);
static void find_command(char *, struct cmdentry *, int, const char *);
static struct builtincmd *find_builtin(const char *);
static void hashcd(void);
static void changepath(const char *);
static void defun(char *, union node *);
static void unsetfunc(const char *);

#ifdef CONFIG_ASH_MATH_SUPPORT
static long dash_arith(const char *);
#endif

#ifdef CONFIG_ASH_RANDOM_SUPPORT
static unsigned long rseed;
static void change_random(const char *);
# ifndef DYNAMIC_VAR
#  define DYNAMIC_VAR
# endif
#endif

/*      $NetBSD: init.h,v 1.9 2002/11/24 22:35:40 christos Exp $        */

static void reset(void);

/*      $NetBSD: var.h,v 1.21 2003/01/22 20:36:04 dsl Exp $     */

/*
 * Shell variables.
 */

/* flags */
#define VEXPORT         0x01    /* variable is exported */
#define VREADONLY       0x02    /* variable cannot be modified */
#define VSTRFIXED       0x04    /* variable struct is statically allocated */
#define VTEXTFIXED      0x08    /* text is statically allocated */
#define VSTACK          0x10    /* text is allocated on the stack */
#define VUNSET          0x20    /* the variable is not set */
#define VNOFUNC         0x40    /* don't call the callback function */
#define VNOSET          0x80    /* do not set variable - just readonly test */
#define VNOSAVE         0x100   /* when text is on the heap before setvareq */
#ifdef DYNAMIC_VAR
# define VDYNAMIC        0x200   /* dynamic variable */
# else
# define VDYNAMIC        0
#endif

struct var {
	struct var *next;               /* next entry in hash list */
	int flags;                      /* flags are defined above */
	const char *text;               /* name=value */
	void (*func)(const char *);     /* function to be called when  */
					/* the variable gets set/unset */
};

struct localvar {
	struct localvar *next;          /* next local variable in list */
	struct var *vp;                 /* the variable that was made local */
	int flags;                      /* saved flags */
	const char *text;               /* saved text */
};


static struct localvar *localvars;

/*
 * Shell variables.
 */

#ifdef CONFIG_ASH_GETOPTS
static void getoptsreset(const char *);
#endif

#ifdef CONFIG_LOCALE_SUPPORT
#include <locale.h>
static void change_lc_all(const char *value);
static void change_lc_ctype(const char *value);
#endif


#define VTABSIZE 39

static const char defpathvar[] = "PATH=/usr/local/bin:/usr/bin:/sbin:/bin";
#ifdef IFS_BROKEN
static const char defifsvar[] = "IFS= \t\n";
#define defifs (defifsvar + 4)
#else
static const char defifs[] = " \t\n";
#endif


static struct var varinit[] = {
#ifdef IFS_BROKEN
	{ 0,    VSTRFIXED|VTEXTFIXED,           defifsvar,      0 },
#else
	{ 0,    VSTRFIXED|VTEXTFIXED|VUNSET,    "IFS\0",        0 },
#endif

#ifdef CONFIG_ASH_MAIL
	{ 0,    VSTRFIXED|VTEXTFIXED|VUNSET,    "MAIL\0",       changemail },
	{ 0,    VSTRFIXED|VTEXTFIXED|VUNSET,    "MAILPATH\0",   changemail },
#endif

	{ 0,    VSTRFIXED|VTEXTFIXED,           defpathvar,     changepath },
	{ 0,    VSTRFIXED|VTEXTFIXED,           "PS1=$ ",       0          },
	{ 0,    VSTRFIXED|VTEXTFIXED,           "PS2=> ",       0          },
	{ 0,    VSTRFIXED|VTEXTFIXED,           "PS4=+ ",       0          },
#ifdef CONFIG_ASH_GETOPTS
	{ 0,    VSTRFIXED|VTEXTFIXED,           "OPTIND=1",     getoptsreset },
#endif
#ifdef CONFIG_ASH_RANDOM_SUPPORT
	{0, VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "RANDOM\0", change_random },
#endif
#ifdef CONFIG_LOCALE_SUPPORT
	{0, VSTRFIXED | VTEXTFIXED | VUNSET, "LC_ALL\0", change_lc_all },
	{0, VSTRFIXED | VTEXTFIXED | VUNSET, "LC_CTYPE\0", change_lc_ctype },
#endif
#ifdef CONFIG_FEATURE_COMMAND_SAVEHISTORY
	{0, VSTRFIXED | VTEXTFIXED | VUNSET, "HISTFILE\0", NULL },
#endif
};

#define vifs varinit[0]
#ifdef CONFIG_ASH_MAIL
#define vmail (&vifs)[1]
#define vmpath (&vmail)[1]
#else
#define vmpath vifs
#endif
#define vpath (&vmpath)[1]
#define vps1 (&vpath)[1]
#define vps2 (&vps1)[1]
#define vps4 (&vps2)[1]
#define voptind (&vps4)[1]
#ifdef CONFIG_ASH_GETOPTS
#define vrandom (&voptind)[1]
#else
#define vrandom (&vps4)[1]
#endif
#define defpath (defpathvar + 5)

/*
 * The following macros access the values of the above variables.
 * They have to skip over the name.  They return the null string
 * for unset variables.
 */

#define ifsval()        (vifs.text + 4)
#define ifsset()        ((vifs.flags & VUNSET) == 0)
#define mailval()       (vmail.text + 5)
#define mpathval()      (vmpath.text + 9)
#define pathval()       (vpath.text + 5)
#define ps1val()        (vps1.text + 4)
#define ps2val()        (vps2.text + 4)
#define ps4val()        (vps4.text + 4)
#define optindval()     (voptind.text + 7)

#define mpathset()      ((vmpath.flags & VUNSET) == 0)

static void setvar(const char *, const char *, int);
static void setvareq(char *, int);
static void listsetvar(struct strlist *, int);
static char *lookupvar(const char *);
static char *bltinlookup(const char *);
static char **listvars(int, int, char ***);
#define environment() listvars(VEXPORT, VUNSET, 0)
static int showvars(const char *, int, int);
static void poplocalvars(void);
static int unsetvar(const char *);
#ifdef CONFIG_ASH_GETOPTS
static int setvarsafe(const char *, const char *, int);
#endif
static int varcmp(const char *, const char *);
static struct var **hashvar(const char *);


static inline int varequal(const char *a, const char *b) {
	return !varcmp(a, b);
}


static int loopnest;            /* current loop nesting level */

/*
 * The parsefile structure pointed to by the global variable parsefile
 * contains information about the current file being read.
 */


struct redirtab {
	struct redirtab *next;
	int renamed[10];
	int nullredirs;
};

static struct redirtab *redirlist;
static int nullredirs;

extern char **environ;

/*      $NetBSD: output.h,v 1.16 2002/11/24 22:35:42 christos Exp $     */


static void outstr(const char *, FILE *);
static void outcslow(int, FILE *);
static void flushall(void);
static void flusherr(void);
static int  out1fmt(const char *, ...)
    __attribute__((__format__(__printf__,1,2)));
static int fmtstr(char *, size_t, const char *, ...)
    __attribute__((__format__(__printf__,3,4)));

static int preverrout_fd;   /* save fd2 before print debug if xflag is set. */


static void out1str(const char *p)
{
	outstr(p, stdout);
}

static void out2str(const char *p)
{
	outstr(p, stderr);
	flusherr();
}

/*
 * Initialization code.
 */

/*
 * This routine initializes the builtin variables.
 */

static inline void
initvar(void)
{
	struct var *vp;
	struct var *end;
	struct var **vpp;

	/*
	 * PS1 depends on uid
	 */
#if defined(CONFIG_FEATURE_COMMAND_EDITING) && defined(CONFIG_FEATURE_SH_FANCY_PROMPT)
	vps1.text = "PS1=\\w \\$ ";
#else
	if (!geteuid())
		vps1.text = "PS1=# ";
#endif
	vp = varinit;
	end = vp + sizeof(varinit) / sizeof(varinit[0]);
	do {
		vpp = hashvar(vp->text);
		vp->next = *vpp;
		*vpp = vp;
	} while (++vp < end);
}

static inline void
init(void)
{

      /* from input.c: */
      {
	      basepf.nextc = basepf.buf = basebuf;
      }

      /* from trap.c: */
      {
	      signal(SIGCHLD, SIG_DFL);
      }

      /* from var.c: */
      {
	      char **envp;
	      char ppid[32];

	      initvar();
	      for (envp = environ ; *envp ; envp++) {
		      if (strchr(*envp, '=')) {
			      setvareq(*envp, VEXPORT|VTEXTFIXED);
		      }
	      }

	      snprintf(ppid, sizeof(ppid), "%d", (int) getppid());
	      setvar("PPID", ppid, 0);
	      setpwd(0, 0);
      }
}

/* PEOF (the end of file marker) */

/*
 * The input line number.  Input.c just defines this variable, and saves
 * and restores it when files are pushed and popped.  The user of this
 * package must set its value.
 */

static int pgetc(void);
static int pgetc2(void);
static int preadbuffer(void);
static void pungetc(void);
static void pushstring(char *, void *);
static void popstring(void);
static void setinputfile(const char *, int);
static void setinputfd(int, int);
static void setinputstring(char *);
static void popfile(void);
static void popallfiles(void);
static void closescript(void);


/*      $NetBSD: jobs.h,v 1.17 2003/01/22 20:36:04 dsl Exp $    */


/* Mode argument to forkshell.  Don't change FORK_FG or FORK_BG. */
#define FORK_FG 0
#define FORK_BG 1
#define FORK_NOJOB 2

/* mode flags for showjob(s) */
#define SHOW_PGID       0x01    /* only show pgid - for jobs -p */
#define SHOW_PID        0x04    /* include process pid */
#define SHOW_CHANGED    0x08    /* only jobs whose state has changed */


/*
 * A job structure contains information about a job.  A job is either a
 * single process or a set of processes contained in a pipeline.  In the
 * latter case, pidlist will be non-NULL, and will point to a -1 terminated
 * array of pids.
 */

struct procstat {
	pid_t   pid;            /* process id */
	int     status;         /* last process status from wait() */
	char    *cmd;           /* text of command being run */
};

struct job {
	struct procstat ps0;    /* status of process */
	struct procstat *ps;    /* status or processes when more than one */
#if JOBS
	int stopstatus;         /* status of a stopped job */
#endif
	uint32_t
		nprocs: 16,     /* number of processes */
		state: 8,
#define JOBRUNNING      0       /* at least one proc running */
#define JOBSTOPPED      1       /* all procs are stopped */
#define JOBDONE         2       /* all procs are completed */
#if JOBS
		sigint: 1,      /* job was killed by SIGINT */
		jobctl: 1,      /* job running under job control */
#endif
		waited: 1,      /* true if this entry has been waited for */
		used: 1,        /* true if this entry is in used */
		changed: 1;     /* true if status has changed */
	struct job *prev_job;   /* previous job */
};

static pid_t backgndpid;        /* pid of last background process */
static int job_warning;         /* user was warned about stopped jobs */
#if JOBS
static int jobctl;              /* true if doing job control */
#endif

static struct job *makejob(union node *, int);
static int forkshell(struct job *, union node *, int);
static int waitforjob(struct job *);
static int stoppedjobs(void);

#if ! JOBS
#define setjobctl(on)   /* do nothing */
#else
static void setjobctl(int);
static void showjobs(FILE *, int);
#endif

/*      $NetBSD: main.h,v 1.9 2002/11/24 22:35:41 christos Exp $        */


/* pid of main shell */
static int rootpid;
/* true if we aren't a child of the main shell */