xref: /titanic_41/usr/src/cmd/csh/sh.h (revision 29949e866e40b95795203f3ee46f44a197c946e4)
1 /*
2  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
7 /*	  All Rights Reserved  	*/
8 
9 /*
10  * Copyright (c) 1980 Regents of the University of California.
11  * All rights reserved.  The Berkeley Software License Agreement
12  * specifies the terms and conditions for redistribution.
13  */
14 
15 #pragma ident	"%Z%%M%	%I%	%E% SMI"
16 
17 #include <stdlib.h>	 /* MB_xxx, mbxxx(), wcxxx() etc. */
18 #include <limits.h>
19 #include <sys/time.h>
20 #include <sys/types.h>
21 #include <sys/siginfo.h>
22 #include <sys/ucontext.h>
23 #include <sys/param.h>
24 #include <sys/stat.h>
25 #include <sys/termios.h>
26 #include <sys/ttold.h>
27 #include <errno.h>
28 #include <signal.h>	/* std sysV signal.h */
29 #include <setjmp.h>
30 #include <sys/resource.h>
31 #include "signal.h"	/* mainly BSD related signal.h */
32 #include "sh.local.h"
33 #include "sh.char.h"
34 
35 /*
36  * MAXHOSTNAMELEN is defined in param.h under SunOS
37  */
38 #define	MAXHOSTNAMELEN	64
39 
40 #ifdef MBCHAR
41 #if !defined(MB_LEN_MAX) || !defined(MB_CUR_MAX)
42 	Error: I need both ANSI macros!
43 #endif
44 #else
45 #if !defined(MB_LEN_MAX)
46 #define	MB_LEN_MAX	1
47 #endif
48 #if !defined(MB_CUR_MAX)
49 #define	MB_CUR_MAX	1
50 #endif
51 #endif
52 
53 #ifndef MBCHAR /* Let's replace the ANSI functions with our own macro
54 		* for efficiency!
55 		*/
56 #define	mbtowc(pwc, pmb, n_is_ignored)	((*(pwc) = *(pmb)), 1)
57 #define	wctomb(pmb, wc)			((*(pmb) = ((char)wc)), 1)
58 #endif /* !MBCHAR */
59 
60 /*
61  * C shell
62  *
63  * Bill Joy, UC Berkeley
64  * October, 1978; May 1980
65  *
66  * Jim Kulp, IIASA, Laxenburg Austria
67  * April, 1980
68  */
69 
70 /*
71  * If we are setting the $cwd variable becuz we did a
72  * cd, chdir, pushd, popd command, then set didchdir to
73  * 1.  This prevents globbing down when setting $cwd.
74  * However, if the user set $cwd, we want the globbing
75  * done; so, didchdir would be equal to 0 in that case.
76  */
77 int didchdir;
78 
79 #define	isdir(d)	((d.st_mode & S_IFMT) == S_IFDIR)
80 
81 typedef	char	bool;
82 
83 /*
84  * tchar (Tagged CHARacter) is a place holder to keep a QUOTE bit and
85  * a character.
86  * For European language handling, lower 8 bits of tchar is used
87  * to store a character.  For other languages, especially Asian, 16 bits
88  * are used to store a character.
89  * Following typedef's assume short int is a 16-bit entity and long int is
90  * a 32-bit entity.
91  * The QUOTE bit tells whether the character is subject to further
92  * interpretation such as history substitution, file mathing, command
93  * subsitution.  TRIM is a mask to strip off the QUOTE bit.
94  */
95 #ifdef MBCHAR		/* For multibyte character handling. */
96 typedef long int	tchar;
97 #define	QUOTE	0x80000000
98 #define	TRIM	0x7fffffff
99 #else /* !MBCHAR */	/* European language requires only 8 bits. */
100 typedef unsigned short int	tchar;
101 #define	QUOTE	0x8000
102 #define	TRIM	0x00ff
103 #endif /* !MBCHAR */
104 #define	eq(a, b)	(strcmp_(a, b) == 0)
105 
106 
107 /*
108  * Global flags
109  */
110 bool	chkstop;		/* Warned of stopped jobs... allow exit */
111 bool	didfds;			/* Have setup i/o fd's for child */
112 bool	doneinp;		/* EOF indicator after reset from readc */
113 bool	exiterr;		/* Exit if error or non-zero exit status */
114 bool	child;			/* Child shell ... errors cause exit */
115 bool	haderr;			/* Reset was because of an error */
116 bool	intty;			/* Input is a tty */
117 bool	cflg;			/* invoked with -c option */
118 bool	intact;			/* We are interactive... therefore prompt */
119 bool	justpr;			/* Just print because of :p hist mod */
120 bool	loginsh;		/* We are a loginsh -> .login/.logout */
121 bool	neednote;		/* Need to pnotify() */
122 bool	noexec;			/* Don't execute, just syntax check */
123 bool	pjobs;			/* want to print jobs if interrupted */
124 bool	pfcshflag;		/* set to 0 for pfcsh */
125 bool	setintr;		/* Set interrupts on/off -> Wait intr... */
126 bool	timflg;			/* Time the next waited for command */
127 bool	havhash;		/* path hashing is available */
128 bool	havhash2;		/* cdpath hashing is available */
129 #ifdef FILEC
130 bool	filec;			/* doing filename expansion */
131 #endif
132 
133 /*
134  * Global i/o info
135  */
136 tchar	*arginp;		/* Argument input for sh -c and internal `xx` */
137 int	onelflg;		/* 2 -> need line for -t, 1 -> exit on read */
138 tchar	*file;			/* Name of shell file for $0 */
139 
140 char	*err;			/* Error message from scanner/parser */
141 struct	timeval time0;		/* Time at which the shell started */
142 struct	rusage ru0;
143 
144 /*
145  * Miscellany
146  */
147 tchar	*doldol;		/* Character pid for $$ */
148 int	uid;			/* Invokers uid */
149 time_t	chktim;			/* Time mail last checked */
150 int	shpgrp;			/* Pgrp of shell */
151 int	tpgrp;			/* Terminal process group */
152 /* If tpgrp is -1, leave tty alone! */
153 int	opgrp;			/* Initial pgrp and tty pgrp */
154 int	oldisc;			/* Initial line discipline or -1 */
155 
156 /*
157  * These are declared here because they want to be
158  * initialized in sh.init.c (to allow them to be made readonly)
159  */
160 
161 extern struct	biltins {
162 	tchar	*bname;
163 	int	(*bfunct)();
164 	short	minargs, maxargs;
165 } bfunc[];
166 extern int nbfunc;
167 
168 extern struct srch {
169 	tchar	*s_name;
170 	short	s_value;
171 } srchn[];
172 extern int nsrchn;
173 
174 /*
175  * To be able to redirect i/o for builtins easily, the shell moves the i/o
176  * descriptors it uses away from 0,1,2.
177  * Ideally these should be in units which are closed across exec's
178  * (this saves work) but for version 6, this is not usually possible.
179  * The desired initial values for these descriptors are defined in
180  * sh.local.h.
181  */
182 short	SHIN;			/* Current shell input (script) */
183 short	SHOUT;			/* Shell output */
184 short	SHDIAG;			/* Diagnostic output... shell errs go here */
185 short	OLDSTD;			/* Old standard input (def for cmds) */
186 
187 /*
188  * Error control
189  *
190  * Errors in scanning and parsing set up an error message to be printed
191  * at the end and complete.  Other errors always cause a reset.
192  * Because of source commands and .cshrc we need nested error catches.
193  */
194 
195 jmp_buf	reslab;
196 
197 #define	setexit()	((void) setjmp(reslab))
198 #define	reset()		longjmp(reslab, 0)
199 	/* Should use structure assignment here */
200 #define	getexit(a)	copy((void *)(a), (void *)reslab, sizeof reslab)
201 #define	resexit(a)	copy((void *)reslab, ((void *)(a)), sizeof reslab)
202 
203 tchar	*gointr;		/* Label for an onintr transfer */
204 void	(*parintr)();		/* Parents interrupt catch */
205 void	(*parterm)();		/* Parents terminate catch */
206 
207 
208 /*
209  * Each level of input has a buffered input structure.
210  * There are one or more blocks of buffered input for each level,
211  * exactly one if the input is seekable and tell is available.
212  * In other cases, the shell buffers enough blocks to keep all loops
213  * in the buffer.
214  */
215 struct	Bin {
216 	off_t	Bfseekp;		/* Seek pointer */
217 	off_t	Bfbobp;			/* Seekp of beginning of buffers */
218 	off_t	Bfeobp;			/* Seekp of end of buffers */
219 	short	Bfblocks;		/* Number of buffer blocks */
220 	tchar	**Bfbuf;		/* The array of buffer blocks */
221 } B;
222 
223 #define	fseekp	B.Bfseekp
224 #define	fbobp	B.Bfbobp
225 #define	feobp	B.Bfeobp
226 #define	fblocks	B.Bfblocks
227 #define	fbuf	B.Bfbuf
228 
229 #define	btell()	fseekp
230 
231 #ifndef btell
232 off_t	btell(void);
233 #endif
234 
235 /*
236  * The shell finds commands in loops by reseeking the input
237  * For whiles, in particular, it reseeks to the beginning of the
238  * line the while was on; hence the while placement restrictions.
239  */
240 off_t	lineloc;
241 
242 #ifdef	TELL
243 bool	cantell;			/* Is current source tellable ? */
244 #endif
245 
246 /*
247  * Input lines are parsed into doubly linked circular
248  * lists of words of the following form.
249  */
250 struct	wordent {
251 	tchar	*word;
252 	struct	wordent *prev;
253 	struct	wordent *next;
254 };
255 
256 /*
257  * During word building, both in the initial lexical phase and
258  * when expanding $ variable substitutions, expansion by `!' and `$'
259  * must be inhibited when reading ahead in routines which are themselves
260  * processing `!' and `$' expansion or after characters such as `\' or in
261  * quotations.  The following flags are passed to the getC routines
262  * telling them which of these substitutions are appropriate for the
263  * next character to be returned.
264  */
265 #define	DODOL	1
266 #define	DOEXCL	2
267 #define	DOALL	DODOL|DOEXCL
268 
269 /*
270  * Labuf implements a general buffer for lookahead during lexical operations.
271  * Text which is to be placed in the input stream can be stuck here.
272  * We stick parsed ahead $ constructs during initial input,
273  * process id's from `$$', and modified variable values (from qualifiers
274  * during expansion in sh.dol.c) here.
275  */
276 tchar	*labuf;
277 
278 tchar	*lap;
279 
280 /*
281  * Parser structure
282  *
283  * Each command is parsed to a tree of command structures and
284  * flags are set bottom up during this process, to be propagated down
285  * as needed during the semantics/exeuction pass (sh.sem.c).
286  */
287 struct	command {
288 	short	t_dtyp;				/* Type of node */
289 	short	t_dflg;				/* Flags, e.g. FAND|... */
290 	union {
291 		tchar	*T_dlef;		/* Input redirect word */
292 		struct	command *T_dcar;	/* Left part of list/pipe */
293 	} L;
294 	union {
295 		tchar	*T_drit;		/* Output redirect word */
296 		struct	command *T_dcdr;	/* Right part of list/pipe */
297 	} R;
298 #define	t_dlef	L.T_dlef
299 #define	t_dcar	L.T_dcar
300 #define	t_drit	R.T_drit
301 #define	t_dcdr	R.T_dcdr
302 	tchar	**t_dcom;			/* Command/argument vector */
303 	char	*cfname;			/* char pathname for execv */
304 	char	**cargs;			/* char arg vec  for execv */
305 	struct	command *t_dspr;		/* Pointer to ()'d subtree */
306 	short	t_nice;
307 };
308 
309 #define	TCOM	1		/* t_dcom <t_dlef >t_drit	*/
310 #define	TPAR	2		/* ( t_dspr ) <t_dlef >t_drit	*/
311 #define	TFIL	3		/* t_dlef | t_drit		*/
312 #define	TLST	4		/* t_dlef ; t_drit		*/
313 #define	TOR	5		/* t_dlef || t_drit		*/
314 #define	TAND	6		/* t_dlef && t_drit		*/
315 
316 #define	FSAVE	(FNICE|FTIME|FNOHUP)	/* save these when re-doing */
317 
318 #define	FAND	(1<<0)		/* executes in background	*/
319 #define	FCAT	(1<<1)		/* output is redirected >>	*/
320 #define	FPIN	(1<<2)		/* input is a pipe		*/
321 #define	FPOU	(1<<3)		/* output is a pipe		*/
322 #define	FPAR	(1<<4)		/* don't fork, last ()ized cmd	*/
323 #define	FINT	(1<<5)		/* should be immune from intr's */
324 /* spare */
325 #define	FDIAG	(1<<7)		/* redirect unit 2 with unit 1	*/
326 #define	FANY	(1<<8)		/* output was !			*/
327 #define	FHERE	(1<<9)		/* input redirection is <<	*/
328 #define	FREDO	(1<<10)		/* reexec aft if, repeat,...	*/
329 #define	FNICE	(1<<11)		/* t_nice is meaningful */
330 #define	FNOHUP	(1<<12)		/* nohup this command */
331 #define	FTIME	(1<<13)		/* time this command */
332 
333 /*
334  * The keywords for the parser
335  */
336 #define	ZBREAK		0
337 #define	ZBRKSW		1
338 #define	ZCASE		2
339 #define	ZDEFAULT 	3
340 #define	ZELSE		4
341 #define	ZEND		5
342 #define	ZENDIF		6
343 #define	ZENDSW		7
344 #define	ZEXIT		8
345 #define	ZFOREACH	9
346 #define	ZGOTO		10
347 #define	ZIF		11
348 #define	ZLABEL		12
349 #define	ZLET		13
350 #define	ZSET		14
351 #define	ZSWITCH		15
352 #define	ZTEST		16
353 #define	ZTHEN		17
354 #define	ZWHILE		18
355 
356 /*
357  * Structure defining the existing while/foreach loops at this
358  * source level.  Loops are implemented by seeking back in the
359  * input.  For foreach (fe), the word list is attached here.
360  */
361 struct	whyle {
362 	off_t	w_start;		/* Point to restart loop */
363 	off_t	w_end;			/* End of loop (0 if unknown) */
364 	tchar	**w_fe, **w_fe0;	/* Current/initial wordlist for fe */
365 	tchar	*w_fename;		/* Name for fe */
366 	struct	whyle *w_next;		/* Next (more outer) loop */
367 } *whyles;
368 
369 /*
370  * Variable structure
371  *
372  * Aliases and variables are stored in AVL balanced binary trees.
373  */
374 struct	varent {
375 	tchar	**vec;		/* Array of words which is the value */
376 	tchar	*v_name;	/* Name of variable/alias */
377 	struct	varent *v_link[3];	/* The links, see below */
378 	int	v_bal;		/* Balance factor */
379 } shvhed, aliases;
380 #define	v_left		v_link[0]
381 #define	v_right		v_link[1]
382 #define	v_parent	v_link[2]
383 
384 struct varent *adrof1();
385 #define	adrof(v)	adrof1(v, &shvhed)
386 #define	value(v)	value1(v, &shvhed)
387 
388 /*
389  * MAX_VAR_LEN - maximum variable name defined by csh man page to be 128
390  */
391 #define	MAX_VAR_LEN	128
392 
393 /*
394  * MAX_VREF_LEN - maximum variable reference $name[...]
395  * it can be as big as a csh word, which is 1024
396  */
397 #define	MAX_VREF_LEN	1024
398 
399 
400 /*
401  * The following are for interfacing redo substitution in
402  * aliases to the lexical routines.
403  */
404 struct	wordent *alhistp;		/* Argument list (first) */
405 struct	wordent *alhistt;		/* Node after last in arg list */
406 tchar	**alvec;			/* The (remnants of) alias vector */
407 
408 /*
409  * Filename/command name expansion variables
410  */
411 short	gflag;				/* After tglob -> is globbing needed? */
412 
413 /*
414  * A reasonable limit on number of arguments would seem to be
415  * the maximum number of characters in an arg list / 6.
416  *
417  * XXX:	With the new VM system, NCARGS has become enormous, making
418  *	it impractical to allocate arrays with NCARGS / 6 entries on
419  *	the stack.  The proper fix is to revamp code elsewhere (in
420  *	sh.dol.c and sh.glob.c) to use a different technique for handling
421  *	command line arguments.  In the meantime, we simply fall back
422  *	on using the old value of NCARGS.
423  */
424 #ifdef	notyet
425 #define	GAVSIZ	(NCARGS / 6)
426 #else	/* notyet */
427 #define	GAVSIZ	(10240 / 6)
428 #endif	/* notyet */
429 
430 /*
431  * Variables for filename expansion
432  */
433 tchar	**gargv;			/* Pointer to the (stack) arglist */
434 long	gargc;				/* Number args in gargv */
435 long	gnleft;
436 
437 /*
438  * Variables for command expansion.
439  */
440 tchar	**pargv;			/* Pointer to the argv list space */
441 tchar	*pargs;				/* Pointer to start current word */
442 long	pargc;				/* Count of arguments in pargv */
443 long	pnleft;				/* Number of chars left in pargs */
444 tchar	*pargcp;			/* Current index into pargs */
445 
446 /*
447  * History list
448  *
449  * Each history list entry contains an embedded wordlist
450  * from the scanner, a number for the event, and a reference count
451  * to aid in discarding old entries.
452  *
453  * Essentially "invisible" entries are put on the history list
454  * when history substitution includes modifiers, and thrown away
455  * at the next discarding since their event numbers are very negative.
456  */
457 struct	Hist {
458 	struct	wordent Hlex;
459 	int	Hnum;
460 	int	Href;
461 	struct	Hist *Hnext;
462 } Histlist;
463 
464 struct	wordent	paraml;			/* Current lexical word list */
465 int	eventno;			/* Next events number */
466 int	lastev;				/* Last event reference (default) */
467 
468 tchar	HIST;				/* history invocation character */
469 tchar	HISTSUB;			/* auto-substitute character */
470 
471 extern void	*xalloc(size_t);
472 extern void	*xcalloc(size_t, size_t);
473 extern void	*xrealloc(void *, size_t);
474 extern void	xfree(void *);
475 
476 extern void	Putchar(tchar);
477 extern void	bferr(char *)	__NORETURN;
478 extern void	error()	__NORETURN;
479 extern void	exitstat(void)	__NORETURN;
480 extern tchar	*Dfix1(tchar *);
481 extern tchar	**blkcpy(tchar **, tchar **);
482 extern tchar	**blkspl(tchar **, tchar **);
483 extern char	**blkspl_(char **, char **);
484 extern tchar	**copyblk(tchar **);
485 extern tchar	**dobackp(tchar *, bool);
486 extern tchar	*domod(tchar *, int);
487 extern struct	Hist *enthist(int, struct wordent *, bool);
488 extern tchar	*getenv_(tchar *);
489 extern tchar	*getenvs_(char *);
490 extern tchar	*getwd_(tchar *);
491 extern tchar	**glob(tchar **);
492 extern tchar	*globone(tchar *);
493 extern tchar	*index_(tchar *, tchar);
494 extern struct biltins	*isbfunc(struct command *);
495 extern void	pintr(void);
496 extern void	pchild(void);
497 extern tchar	*putn(int);
498 extern tchar	*rindex_(tchar *, tchar);
499 extern tchar	**saveblk(tchar **);
500 extern tchar	*savestr(tchar *);
501 extern tchar	*strcat_(tchar *, tchar *);
502 extern int	strlen_(tchar *);
503 extern tchar	*strcpy_(tchar *, tchar *);
504 extern tchar	*strend(tchar *);
505 extern tchar	*strip(tchar *);
506 extern tchar	*strspl(tchar *, tchar *);
507 extern struct command	*syntax(struct wordent *, struct wordent *, int);
508 extern tchar	*value1(tchar *, struct varent *);
509 
510 #define	NOSTR	((tchar *) 0)
511 
512 /*
513  * setname is a macro to copy the path in bname. (see sh.err.c)
514  * Here we are dynamically reallocating the bname to the new length
515  * to store the new path
516  */
517 tchar	*bname;
518 #define	setname(a)	 { \
519 	bname = xrealloc(bname, (strlen_(a)+1) * sizeof (tchar)); \
520 	strcpy_(bname, a); \
521 	bname[strlen_(a)] = '\0'; \
522 }
523 
524 #ifdef VFORK
525 tchar	*Vsav;
526 tchar	**Vav;
527 tchar	*Vdp;
528 #endif
529 
530 tchar	**evalvec;
531 tchar	*evalp;
532 
533 /* Conversion functions between char and tchar strings. */
534 tchar	*strtots(/* tchar * , char * */);
535 char	*tstostr(/* char *  , tchar * */);
536 
537 #ifndef NULL
538 #define	NULL	0
539 #endif
540 
541 
542 /*
543  * Xhash is an array of HSHSIZ bits (HSHSIZ / 8 chars), which are used
544  * to hash execs.  If it is allocated (havhash true), then to tell
545  * whether ``name'' is (possibly) present in the i'th component
546  * of the variable path, you look at the bit in xhash indexed by
547  * hash(hashname("name"), i).  This is setup automatically
548  * after .login is executed, and recomputed whenever ``path'' is
549  * changed.
550  * The two part hash function is designed to let texec() call the
551  * more expensive hashname() only once and the simple hash() several
552  * times (once for each path component checked).
553  * Byte size is assumed to be 8.
554  */
555 #define	HSHSIZ		(32*1024)	/* 4k bytes */
556 #define	HSHMASK		(HSHSIZ - 1)
557 #define	HSHMUL		243
558 
559 /*
560  * The following two arrays are used for caching.  xhash
561  * is for caching path variable and xhash2 is for cdpath
562  * variable.
563  */
564 
565 char xhash[HSHSIZ / 8];
566 char xhash2[HSHSIZ / 8];
567 #define	hash(a, b)	((a) * HSHMUL + (b) & HSHMASK)
568 #define	bit(h, b)	((h)[(b) >> 3] & 1 << ((b) & 7))	/* bit test */
569 #define	bis(h, b)	((h)[(b) >> 3] |= 1 << ((b) & 7))	/* bit set */
570 #ifdef VFORK
571 int	hits, misses;
572 #endif
573