xref: /openbsd-src/bin/ksh/io.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*	$OpenBSD: io.c,v 1.35 2016/03/20 00:01:21 krw Exp $	*/
2 
3 /*
4  * shell buffered IO and formatted output
5  */
6 
7 #include <sys/stat.h>
8 
9 #include <ctype.h>
10 #include <errno.h>
11 #include <fcntl.h>
12 #include <string.h>
13 #include <unistd.h>
14 
15 #include "sh.h"
16 
17 static int initio_done;
18 
19 /*
20  * formatted output functions
21  */
22 
23 
24 /* A shell error occurred (eg, syntax error, etc.) */
25 void
26 errorf(const char *fmt, ...)
27 {
28 	va_list va;
29 
30 	shl_stdout_ok = 0;	/* debugging: note that stdout not valid */
31 	exstat = 1;
32 	if (fmt != NULL && *fmt != '\0') {
33 		error_prefix(true);
34 		va_start(va, fmt);
35 		shf_vfprintf(shl_out, fmt, va);
36 		va_end(va);
37 		shf_putchar('\n', shl_out);
38 	}
39 	shf_flush(shl_out);
40 	unwind(LERROR);
41 }
42 
43 /* like errorf(), but no unwind is done */
44 void
45 warningf(bool show_lineno, const char *fmt, ...)
46 {
47 	va_list va;
48 
49 	error_prefix(show_lineno);
50 	va_start(va, fmt);
51 	shf_vfprintf(shl_out, fmt, va);
52 	va_end(va);
53 	shf_putchar('\n', shl_out);
54 	shf_flush(shl_out);
55 }
56 
57 /* Used by built-in utilities to prefix shell and utility name to message
58  * (also unwinds environments for special builtins).
59  */
60 void
61 bi_errorf(const char *fmt, ...)
62 {
63 	va_list va;
64 
65 	shl_stdout_ok = 0;	/* debugging: note that stdout not valid */
66 	exstat = 1;
67 	if (fmt != NULL && *fmt != '\0') {
68 		error_prefix(true);
69 		/* not set when main() calls parse_args() */
70 		if (builtin_argv0)
71 			shf_fprintf(shl_out, "%s: ", builtin_argv0);
72 		va_start(va, fmt);
73 		shf_vfprintf(shl_out, fmt, va);
74 		va_end(va);
75 		shf_putchar('\n', shl_out);
76 	}
77 	shf_flush(shl_out);
78 	/* POSIX special builtins and ksh special builtins cause
79 	 * non-interactive shells to exit.
80 	 * XXX odd use of KEEPASN; also may not want LERROR here
81 	 */
82 	if ((builtin_flag & SPEC_BI) ||
83 	    (Flag(FPOSIX) && (builtin_flag & KEEPASN))) {
84 		builtin_argv0 = NULL;
85 		unwind(LERROR);
86 	}
87 }
88 
89 /* Called when something that shouldn't happen does */
90 void
91 internal_errorf(int jump, const char *fmt, ...)
92 {
93 	va_list va;
94 
95 	error_prefix(true);
96 	shf_fprintf(shl_out, "internal error: ");
97 	va_start(va, fmt);
98 	shf_vfprintf(shl_out, fmt, va);
99 	va_end(va);
100 	shf_putchar('\n', shl_out);
101 	shf_flush(shl_out);
102 	if (jump)
103 		unwind(LERROR);
104 }
105 
106 /* used by error reporting functions to print "ksh: .kshrc[25]: " */
107 void
108 error_prefix(int fileline)
109 {
110 	/* Avoid foo: foo[2]: ... */
111 	if (!fileline || !source || !source->file ||
112 	    strcmp(source->file, kshname) != 0)
113 		shf_fprintf(shl_out, "%s: ", kshname + (*kshname == '-'));
114 	if (fileline && source && source->file != NULL) {
115 		shf_fprintf(shl_out, "%s[%d]: ", source->file,
116 		    source->errline > 0 ? source->errline : source->line);
117 		source->errline = 0;
118 	}
119 }
120 
121 /* printf to shl_out (stderr) with flush */
122 void
123 shellf(const char *fmt, ...)
124 {
125 	va_list va;
126 
127 	if (!initio_done) /* shl_out may not be set up yet... */
128 		return;
129 	va_start(va, fmt);
130 	shf_vfprintf(shl_out, fmt, va);
131 	va_end(va);
132 	shf_flush(shl_out);
133 }
134 
135 /* printf to shl_stdout (stdout) */
136 void
137 shprintf(const char *fmt, ...)
138 {
139 	va_list va;
140 
141 	if (!shl_stdout_ok)
142 		internal_errorf(1, "shl_stdout not valid");
143 	va_start(va, fmt);
144 	shf_vfprintf(shl_stdout, fmt, va);
145 	va_end(va);
146 }
147 
148 #ifdef KSH_DEBUG
149 static struct shf *kshdebug_shf;
150 
151 void
152 kshdebug_init_(void)
153 {
154 	if (kshdebug_shf)
155 		shf_close(kshdebug_shf);
156 	kshdebug_shf = shf_open("/tmp/ksh-debug.log",
157 	    O_WRONLY|O_APPEND|O_CREAT, 0600, SHF_WR|SHF_MAPHI);
158 	if (kshdebug_shf) {
159 		shf_fprintf(kshdebug_shf, "\nNew shell[pid %d]\n", getpid());
160 		shf_flush(kshdebug_shf);
161 	}
162 }
163 
164 /* print to debugging log */
165 void
166 kshdebug_printf_(const char *fmt, ...)
167 {
168 	va_list va;
169 
170 	if (!kshdebug_shf)
171 		return;
172 	va_start(va, fmt);
173 	shf_fprintf(kshdebug_shf, "[%d] ", getpid());
174 	shf_vfprintf(kshdebug_shf, fmt, va);
175 	va_end(va);
176 	shf_flush(kshdebug_shf);
177 }
178 
179 void
180 kshdebug_dump_(const char *str, const void *mem, int nbytes)
181 {
182 	int i, j;
183 	int nprow = 16;
184 
185 	if (!kshdebug_shf)
186 		return;
187 	shf_fprintf(kshdebug_shf, "[%d] %s:\n", getpid(), str);
188 	for (i = 0; i < nbytes; i += nprow) {
189 		char c = '\t';
190 
191 		for (j = 0; j < nprow && i + j < nbytes; j++) {
192 			shf_fprintf(kshdebug_shf, "%c%02x", c,
193 			    ((const unsigned char *) mem)[i + j]);
194 			c = ' ';
195 		}
196 		shf_fprintf(kshdebug_shf, "\n");
197 	}
198 	shf_flush(kshdebug_shf);
199 }
200 #endif /* KSH_DEBUG */
201 
202 /* test if we can seek backwards fd (returns 0 or SHF_UNBUF) */
203 int
204 can_seek(int fd)
205 {
206 	struct stat statb;
207 
208 	return fstat(fd, &statb) == 0 && !S_ISREG(statb.st_mode) ?
209 	    SHF_UNBUF : 0;
210 }
211 
212 struct shf	shf_iob[3];
213 
214 void
215 initio(void)
216 {
217 	shf_fdopen(1, SHF_WR, shl_stdout);	/* force buffer allocation */
218 	shf_fdopen(2, SHF_WR, shl_out);
219 	shf_fdopen(2, SHF_WR, shl_spare);	/* force buffer allocation */
220 	initio_done = 1;
221 	kshdebug_init();
222 }
223 
224 /* A dup2() with error checking */
225 int
226 ksh_dup2(int ofd, int nfd, int errok)
227 {
228 	int ret = dup2(ofd, nfd);
229 
230 	if (ret < 0 && errno != EBADF && !errok)
231 		errorf("too many files open in shell");
232 
233 	return ret;
234 }
235 
236 /*
237  * move fd from user space (0<=fd<10) to shell space (fd>=10),
238  * set close-on-exec flag.
239  */
240 int
241 savefd(int fd)
242 {
243 	int nfd;
244 
245 	if (fd < FDBASE) {
246 		nfd = fcntl(fd, F_DUPFD_CLOEXEC, FDBASE);
247 		if (nfd < 0) {
248 			if (errno == EBADF)
249 				return -1;
250 			else
251 				errorf("too many files open in shell");
252 		}
253 	} else {
254 		nfd = fd;
255 		fcntl(nfd, F_SETFD, FD_CLOEXEC);
256 	}
257 	return nfd;
258 }
259 
260 void
261 restfd(int fd, int ofd)
262 {
263 	if (fd == 2)
264 		shf_flush(&shf_iob[fd]);
265 	if (ofd < 0)		/* original fd closed */
266 		close(fd);
267 	else if (fd != ofd) {
268 		ksh_dup2(ofd, fd, true); /* XXX: what to do if this fails? */
269 		close(ofd);
270 	}
271 }
272 
273 void
274 openpipe(int *pv)
275 {
276 	int lpv[2];
277 
278 	if (pipe(lpv) < 0)
279 		errorf("can't create pipe - try again");
280 	pv[0] = savefd(lpv[0]);
281 	if (pv[0] != lpv[0])
282 		close(lpv[0]);
283 	pv[1] = savefd(lpv[1]);
284 	if (pv[1] != lpv[1])
285 		close(lpv[1]);
286 }
287 
288 void
289 closepipe(int *pv)
290 {
291 	close(pv[0]);
292 	close(pv[1]);
293 }
294 
295 /* Called by iosetup() (deals with 2>&4, etc.), c_read, c_print to turn
296  * a string (the X in 2>&X, read -uX, print -uX) into a file descriptor.
297  */
298 int
299 check_fd(char *name, int mode, const char **emsgp)
300 {
301 	int fd, fl;
302 
303 	if (isdigit((unsigned char)name[0]) && !name[1]) {
304 		fd = name[0] - '0';
305 		if ((fl = fcntl(fd, F_GETFL)) < 0) {
306 			if (emsgp)
307 				*emsgp = "bad file descriptor";
308 			return -1;
309 		}
310 		fl &= O_ACCMODE;
311 		/* X_OK is a kludge to disable this check for dups (x<&1):
312 		 * historical shells never did this check (XXX don't know what
313 		 * posix has to say).
314 		 */
315 		if (!(mode & X_OK) && fl != O_RDWR &&
316 		    (((mode & R_OK) && fl != O_RDONLY) ||
317 		    ((mode & W_OK) && fl != O_WRONLY))) {
318 			if (emsgp)
319 				*emsgp = (fl == O_WRONLY) ?
320 				    "fd not open for reading" :
321 				    "fd not open for writing";
322 			return -1;
323 		}
324 		return fd;
325 	} else if (name[0] == 'p' && !name[1])
326 		return coproc_getfd(mode, emsgp);
327 	if (emsgp)
328 		*emsgp = "illegal file descriptor name";
329 	return -1;
330 }
331 
332 /* Called once from main */
333 void
334 coproc_init(void)
335 {
336 	coproc.read = coproc.readw = coproc.write = -1;
337 	coproc.njobs = 0;
338 	coproc.id = 0;
339 }
340 
341 /* Called by c_read() when eof is read - close fd if it is the co-process fd */
342 void
343 coproc_read_close(int fd)
344 {
345 	if (coproc.read >= 0 && fd == coproc.read) {
346 		coproc_readw_close(fd);
347 		close(coproc.read);
348 		coproc.read = -1;
349 	}
350 }
351 
352 /* Called by c_read() and by iosetup() to close the other side of the
353  * read pipe, so reads will actually terminate.
354  */
355 void
356 coproc_readw_close(int fd)
357 {
358 	if (coproc.readw >= 0 && coproc.read >= 0 && fd == coproc.read) {
359 		close(coproc.readw);
360 		coproc.readw = -1;
361 	}
362 }
363 
364 /* Called by c_print when a write to a fd fails with EPIPE and by iosetup
365  * when co-process input is dup'd
366  */
367 void
368 coproc_write_close(int fd)
369 {
370 	if (coproc.write >= 0 && fd == coproc.write) {
371 		close(coproc.write);
372 		coproc.write = -1;
373 	}
374 }
375 
376 /* Called to check for existence of/value of the co-process file descriptor.
377  * (Used by check_fd() and by c_read/c_print to deal with -p option).
378  */
379 int
380 coproc_getfd(int mode, const char **emsgp)
381 {
382 	int fd = (mode & R_OK) ? coproc.read : coproc.write;
383 
384 	if (fd >= 0)
385 		return fd;
386 	if (emsgp)
387 		*emsgp = "no coprocess";
388 	return -1;
389 }
390 
391 /* called to close file descriptors related to the coprocess (if any)
392  * Should be called with SIGCHLD blocked.
393  */
394 void
395 coproc_cleanup(int reuse)
396 {
397 	/* This to allow co-processes to share output pipe */
398 	if (!reuse || coproc.readw < 0 || coproc.read < 0) {
399 		if (coproc.read >= 0) {
400 			close(coproc.read);
401 			coproc.read = -1;
402 		}
403 		if (coproc.readw >= 0) {
404 			close(coproc.readw);
405 			coproc.readw = -1;
406 		}
407 	}
408 	if (coproc.write >= 0) {
409 		close(coproc.write);
410 		coproc.write = -1;
411 	}
412 }
413 
414 
415 /*
416  * temporary files
417  */
418 
419 struct temp *
420 maketemp(Area *ap, Temp_type type, struct temp **tlist)
421 {
422 	struct temp *tp;
423 	int len;
424 	int fd;
425 	char *path;
426 	const char *dir;
427 
428 	dir = tmpdir ? tmpdir : "/tmp";
429 	/* The 20 + 20 is a paranoid worst case for pid/inc */
430 	len = strlen(dir) + 3 + 20 + 20 + 1;
431 	tp = alloc(sizeof(struct temp) + len, ap);
432 	tp->name = path = (char *) &tp[1];
433 	tp->shf = NULL;
434 	tp->type = type;
435 	shf_snprintf(path, len, "%s/shXXXXXXXX", dir);
436 	fd = mkstemp(path);
437 	if (fd >= 0)
438 		tp->shf = shf_fdopen(fd, SHF_WR, NULL);
439 	tp->pid = procpid;
440 
441 	tp->next = *tlist;
442 	*tlist = tp;
443 	return tp;
444 }
445