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1.1 root 1: /* Copyright (c) 1979 Regents of the University of California */
2: #include "sh.local.h"
3: /*
4: * C shell
5: *
6: * Bill Joy, UC Berkeley
7: * October, 1978
8: */
9: #include <sys/types.h>
10: #include <sys/stat.h>
11: #include <sys/dir.h>
12:
13: #define isdir(d) ((d.st_mode & S_IFMT) == S_IFDIR)
14:
15: #include <errno.h>
16: #include <setjmp.h>
17: #include <signal.h>
18:
19: typedef char bool;
20:
21: #define eq(a, b) (strcmp(a, b) == 0)
22:
23: /*
24: * Global flags
25: */
26: bool didcch; /* Have closed unused fd's for child */
27: bool didfds; /* Have setup i/o fd's for child */
28: bool doneinp; /* EOF indicator after reset from readc */
29: bool exiterr; /* Exit if error or non-zero exit status */
30: bool child; /* Child shell ... errors cause exit */
31: bool haderr; /* Reset was because of an error */
32: bool intty; /* Input is a tty */
33: bool intact; /* We are interactive... therefore prompt */
34: bool justpr; /* Just print because of :p hist mod */
35: bool loginsh; /* We are a loginsh -> .login/.logout */
36: bool noexec; /* Don't execute, just syntax check */
37: bool setintr; /* Set interrupts on/off -> Wait intr... */
38: bool timflg; /* Time the next waited for command */
39:
40: /*
41: * Global i/o info
42: */
43: char *arginp; /* Argument input for sh -c and internal `xx` */
44: int onelflg; /* 2 -> need line for -t, 1 -> exit on read */
45: char *file; /* Name of shell file for $0 */
46:
47: char *err; /* Error message from scanner/parser */
48: int errno; /* Error from C library routines */
49: char *shtemp; /* Temp name for << shell files in /tmp */
50: time_t time0; /* Time at which the shell started */
51:
52: /*
53: * Miscellany
54: */
55: char *doldol; /* Character pid for $$ */
56: int uid; /* Invokers uid */
57: time_t chktim; /* Time mail last checked */
58:
59: /*
60: * These are declared here because they want to be
61: * initialized in sh.init.c (to allow them to be made readonly)
62: */
63: char *mesg[];
64:
65: struct biltins {
66: char *bname;
67: int (*bfunct)();
68: short minargs, maxargs;
69: } bfunc[];
70:
71: struct srch {
72: char *s_name;
73: short s_value;
74: } srchn[];
75:
76: /*
77: * To be able to redirect i/o for builtins easily, the shell moves the i/o
78: * descriptors it uses away from 0,1,2.
79: * Ideally these should be in units which are closed across exec's
80: * (this saves work) but for version 6, this is not usually possible.
81: * The desired initial values for these descriptors are defined in
82: * sh.local.h.
83: */
84: short SHIN; /* Current shell input (script) */
85: short SHOUT; /* Shell output */
86: short SHDIAG; /* Diagnostic output... shell errs go here */
87: short OLDSTD; /* Old standard input (def for cmds) */
88:
89: /*
90: * Error control
91: *
92: * Errors in scanning and parsing set up an error message to be printed
93: * at the end and complete. Other errors always cause a reset.
94: * Because of source commands and .cshrc we need nested error catches.
95: */
96:
97: jmp_buf reslab;
98:
99: #define setexit() setjmp(reslab)
100: #define reset() longjmp(reslab)
101: /* Should use structure assignment here */
102: #define getexit(a) copy(a, reslab, sizeof reslab)
103: #define resexit(a) copy(reslab, a, sizeof reslab)
104:
105: char *gointr; /* Label for an onintr transfer */
106: int (*parintr)(); /* Parents interrupt catch */
107: int (*parterm)(); /* Parents terminate catch */
108:
109: /*
110: * Lexical definitions.
111: *
112: * All lexical space is allocated dynamically.
113: * The eighth bit of characters is used to prevent recognition,
114: * and eventually stripped.
115: */
116: #define QUOTE 0200 /* Eighth char bit used internally for 'ing */
117: #define TRIM 0177 /* Mask to strip quote bit */
118:
119: /*
120: * Each level of input has a buffered input structure.
121: * There are one or more blocks of buffered input for each level,
122: * exactly one if the input is seekable and tell is available.
123: * In other cases, the shell buffers enough blocks to keep all loops
124: * in the buffer.
125: */
126: struct Bin {
127: off_t Bfseekp; /* Seek pointer */
128: off_t Bfbobp; /* Seekp of beginning of buffers */
129: off_t Bfeobp; /* Seekp of end of buffers */
130: short Bfblocks; /* Number of buffer blocks */
131: char **Bfbuf; /* The array of buffer blocks */
132: } B;
133:
134: #define fseekp B.Bfseekp
135: #define fbobp B.Bfbobp
136: #define feobp B.Bfeobp
137: #define fblocks B.Bfblocks
138: #define fbuf B.Bfbuf
139:
140: off_t btell();
141:
142: /*
143: * The shell finds commands in loops by reseeking the input
144: * For whiles, in particular, it reseeks to the beginning of the
145: * line the while was on; hence the while placement restrictions.
146: */
147: off_t lineloc;
148:
149: #ifdef TELL
150: off_t tell();
151: bool cantell; /* Is current source tellable ? */
152: #endif
153:
154: /*
155: * Input lines are parsed into doubly linked circular
156: * lists of words of the following form.
157: */
158: struct wordent {
159: char *word;
160: struct wordent *prev;
161: struct wordent *next;
162: };
163:
164: /*
165: * During word building, both in the initial lexical phase and
166: * when expanding $ variable substitutions, expansion by `!' and `$'
167: * must be inhibited when reading ahead in routines which are themselves
168: * processing `!' and `$' expansion or after characters such as `\' or in
169: * quotations. The following flags are passed to the getC routines
170: * telling them which of these substitutions are appropriate for the
171: * next character to be returned.
172: */
173: #define DODOL 1
174: #define DOEXCL 2
175: #define DOALL DODOL|DOEXCL
176:
177: /*
178: * Labuf implements a general buffer for lookahead during lexical operations.
179: * Text which is to be placed in the input stream can be stuck here.
180: * We stick parsed ahead $ constructs during initial input,
181: * process id's from `$$', and modified variable values (from qualifiers
182: * during expansion in sh.dol.c) here.
183: */
184: char labuf[256];
185: char *lap;
186:
187: /*
188: * Parser structure
189: *
190: * Each command is parsed to a tree of command structures and
191: * flags are set bottom up during this process, to be propagated down
192: * as needed during the semantics/exeuction pass (sh.sem.c).
193: */
194: struct command {
195: short t_dtyp; /* Type of node */
196: short t_dflg; /* Flags, e.g. FAND|... */
197: union {
198: char *T_dlef; /* Input redirect word */
199: struct command *T_dcar; /* Left part of list/pipe */
200: } L;
201: union {
202: char *T_drit; /* Output redirect word */
203: struct command *T_dcdr; /* Right part of list/pipe */
204: } R;
205: #define t_dlef L.T_dlef
206: #define t_dcar L.T_dcar
207: #define t_drit R.T_drit
208: #define t_dcdr R.T_dcdr
209: char **t_dcom; /* Command/argument vector */
210: struct command *t_dspr; /* Pointer to ()'d subtree */
211: };
212:
213: #define TCOM 1 /* t_dcom <t_dlef >t_drit */
214: #define TPAR 2 /* ( t_dspr ) <t_dlef >t_drit */
215: #define TFIL 3 /* t_dlef | t_drit */
216: #define TLST 4 /* t_dlef ; t_drit */
217: #define TOR 5 /* t_dlef || t_drit */
218: #define TAND 6 /* t_dlef && t_drit */
219:
220: #define FAND (1<<0) /* executes in background */
221: #define FCAT (1<<1) /* output is redirected >> */
222: #define FPIN (1<<2) /* input is a pipe */
223: #define FPOU (1<<3) /* output is a pipe */
224: #define FPAR (1<<4) /* don't fork, last ()ized cmd */
225: #define FINT (1<<5) /* don't make interruptible */
226: #define FPRS (1<<6) /* print number when forked */
227: #define FDIAG (1<<7) /* redirect unit 2 with unit 1 */
228: #define FANY (1<<8) /* output was ! */
229: #define FHERE (1<<9) /* input redirection is << */
230: #define FREDO (1<<10) /* reexec aft if, repeat,... */
231:
232: /*
233: * The keywords for the parser
234: */
235: #define ZBREAK 0
236: #define ZBRKSW 1
237: #define ZCASE 2
238: #define ZDEFAULT 3
239: #define ZELSE 4
240: #define ZEND 5
241: #define ZENDIF 6
242: #define ZENDSW 7
243: #define ZEXIT 8
244: #define ZFOREACH 9
245: #define ZGOTO 10
246: #define ZIF 11
247: #define ZLABEL 12
248: #define ZLET 13
249: #define ZSET 14
250: #define ZSWITCH 15
251: #define ZTEST 16
252: #define ZTHEN 17
253: #define ZWHILE 18
254:
255: /*
256: * Structure defining the existing while/foreach loops at this
257: * source level. Loops are implemented by seeking back in the
258: * input. For foreach (fe), the word list is attached here.
259: */
260: struct whyle {
261: off_t w_start; /* Point to restart loop */
262: off_t w_end; /* End of loop (0 if unknown) */
263: char **w_fe, **w_fe0; /* Current/initial wordlist for fe */
264: char *w_fename; /* Name for fe */
265: struct whyle *w_next; /* Next (more outer) loop */
266: } *whyles;
267:
268: /*
269: * Variable structure
270: *
271: * Lists of aliases and variables are sorted alphabetically by name
272: */
273: struct varent {
274: char **vec; /* Array of words which is the value */
275: char *name; /* Name of variable/alias */
276: struct varent *link;
277: } shvhed, aliases;
278:
279: /*
280: * The following are for interfacing redo substitution in
281: * aliases to the lexical routines.
282: */
283: struct wordent *alhistp; /* Argument list (first) */
284: struct wordent *alhistt; /* Node after last in arg list */
285: char **alvec; /* The (remnants of) alias vector */
286:
287: /*
288: * Filename/command name expansion variables
289: */
290: short gflag; /* After tglob -> is globbing needed? */
291:
292: /*
293: * A reasonable limit on number of arguments would seem to be
294: * the maximum number of characters in an arg list / 6.
295: */
296: #define GAVSIZ NCARGS / 6
297:
298: /*
299: * Variables for filename expansion
300: */
301: char **gargv; /* Pointer to the (stack) arglist */
302: short gargc; /* Number args in gargv */
303: short gnleft;
304:
305: /*
306: * Variables for command expansion.
307: */
308: char **pargv; /* Pointer to the argv list space */
309: char *pargs; /* Pointer to start current word */
310: short pargc; /* Count of arguments in pargv */
311: short pnleft; /* Number of chars left in pargs */
312: char *pargcp; /* Current index into pargs */
313:
314: /*
315: * History list
316: *
317: * Each history list entry contains an embedded wordlist
318: * from the scanner, a number for the event, and a reference count
319: * to aid in discarding old entries.
320: *
321: * Essentially "invisible" entries are put on the history list
322: * when history substitution includes modifiers, and thrown away
323: * at the next discarding since their event numbers are very negative.
324: */
325: struct Hist {
326: struct wordent Hlex;
327: int Hnum;
328: int Href;
329: struct Hist *Hnext;
330: } Histlist;
331:
332: int eventno; /* Next events number */
333: int lastev; /* Last event reference (default) */
334:
335: char *Dfix1();
336: struct varent *adrof(), *adrof1();
337: char **blkcat();
338: char **blkcpy();
339: char **blkend();
340: char **blkspl();
341: char *calloc();
342: char *cname();
343: char **copyblk();
344: char **dobackp();
345: char *domod();
346: struct wordent *dosub();
347: char *exp3();
348: char *exp3a();
349: char *exp4();
350: char *exp5();
351: char *exp6();
352: struct Hist *enthist();
353: struct Hist *findev();
354: struct wordent *freenod();
355: char *getenv();
356: char *getinx();
357: struct varent *getvx();
358: struct passwd *getpwnam();
359: struct wordent *gethent();
360: struct wordent *getsub();
361: char *globone();
362: struct biltins *isbfunc();
363: char **glob();
364: char *operate();
365: int pintr();
366: char *putn();
367: char **saveblk();
368: char *savestr();
369: char *strcat();
370: char *strcpy();
371: char *strend();
372: char *strings();
373: char *strip();
374: char *strspl();
375: char *subword();
376: struct command *syntax();
377: struct command *syn0();
378: struct command *syn1();
379: struct command *syn1a();
380: struct command *syn1b();
381: struct command *syn2();
382: struct command *syn3();
383: int tglob();
384: int trim();
385: char *value(), *value1();
386: char *xhome();
387: char *xname();
388: char *xset();
389:
390: #define NOSTR ((char *) 0)
391:
392: /*
393: * setname is a macro to save space (see sh.err.c)
394: */
395: char *bname;
396: #define setname(a) bname = (a);
397:
398: #ifdef VFORK
399: char *Vsav;
400: char **Vav;
401: char *Vdp;
402: #endif
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