xref: /openbsd/bin/ksh/io.c (revision d415bd75)
1 /*	$OpenBSD: io.c,v 1.38 2019/07/24 14:33:16 bcallah 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 <stdlib.h>
13 #include <string.h>
14 #include <unistd.h>
15 
16 #include "sh.h"
17 
18 static int initio_done;
19 
20 /*
21  * formatted output functions
22  */
23 
24 
25 /* A shell error occurred (eg, syntax error, etc.) */
26 void
27 errorf(const char *fmt, ...)
28 {
29 	va_list va;
30 
31 	shl_stdout_ok = 0;	/* debugging: note that stdout not valid */
32 	exstat = 1;
33 	if (fmt != NULL && *fmt != '\0') {
34 		error_prefix(true);
35 		va_start(va, fmt);
36 		shf_vfprintf(shl_out, fmt, va);
37 		va_end(va);
38 		shf_putchar('\n', shl_out);
39 	}
40 	shf_flush(shl_out);
41 	unwind(LERROR);
42 }
43 
44 /* like errorf(), but no unwind is done */
45 void
46 warningf(bool show_lineno, const char *fmt, ...)
47 {
48 	va_list va;
49 
50 	error_prefix(show_lineno);
51 	va_start(va, fmt);
52 	shf_vfprintf(shl_out, fmt, va);
53 	va_end(va);
54 	shf_putchar('\n', shl_out);
55 	shf_flush(shl_out);
56 }
57 
58 /* Used by built-in utilities to prefix shell and utility name to message
59  * (also unwinds environments for special builtins).
60  */
61 void
62 bi_errorf(const char *fmt, ...)
63 {
64 	va_list va;
65 
66 	shl_stdout_ok = 0;	/* debugging: note that stdout not valid */
67 	exstat = 1;
68 	if (fmt != NULL && *fmt != '\0') {
69 		error_prefix(true);
70 		/* not set when main() calls parse_args() */
71 		if (builtin_argv0)
72 			shf_fprintf(shl_out, "%s: ", builtin_argv0);
73 		va_start(va, fmt);
74 		shf_vfprintf(shl_out, fmt, va);
75 		va_end(va);
76 		shf_putchar('\n', shl_out);
77 	}
78 	shf_flush(shl_out);
79 	/* POSIX special builtins and ksh special builtins cause
80 	 * non-interactive shells to exit.
81 	 * XXX odd use of KEEPASN; also may not want LERROR here
82 	 */
83 	if ((builtin_flag & SPEC_BI) ||
84 	    (Flag(FPOSIX) && (builtin_flag & KEEPASN))) {
85 		builtin_argv0 = NULL;
86 		unwind(LERROR);
87 	}
88 }
89 
90 static void
91 internal_error_vwarn(const char *fmt, va_list va)
92 {
93 	error_prefix(true);
94 	shf_fprintf(shl_out, "internal error: ");
95 	shf_vfprintf(shl_out, fmt, va);
96 	shf_putchar('\n', shl_out);
97 	shf_flush(shl_out);
98 }
99 
100 /* Warn when something that shouldn't happen does */
101 void
102 internal_warningf(const char *fmt, ...)
103 {
104 	va_list va;
105 
106 	va_start(va, fmt);
107 	internal_error_vwarn(fmt, va);
108 	va_end(va);
109 }
110 
111 /* Warn and unwind when something that shouldn't happen does */
112 __dead void
113 internal_errorf(const char *fmt, ...)
114 {
115 	va_list va;
116 
117 	va_start(va, fmt);
118 	internal_error_vwarn(fmt, va);
119 	va_end(va);
120 	unwind(LERROR);
121 }
122 
123 /* used by error reporting functions to print "ksh: .kshrc[25]: " */
124 void
125 error_prefix(int fileline)
126 {
127 	/* Avoid foo: foo[2]: ... */
128 	if (!fileline || !source || !source->file ||
129 	    strcmp(source->file, kshname) != 0)
130 		shf_fprintf(shl_out, "%s: ", kshname + (*kshname == '-'));
131 	if (fileline && source && source->file != NULL) {
132 		shf_fprintf(shl_out, "%s[%d]: ", source->file,
133 		    source->errline > 0 ? source->errline : source->line);
134 		source->errline = 0;
135 	}
136 }
137 
138 /* printf to shl_out (stderr) with flush */
139 void
140 shellf(const char *fmt, ...)
141 {
142 	va_list va;
143 
144 	if (!initio_done) /* shl_out may not be set up yet... */
145 		return;
146 	va_start(va, fmt);
147 	shf_vfprintf(shl_out, fmt, va);
148 	va_end(va);
149 	shf_flush(shl_out);
150 }
151 
152 /* printf to shl_stdout (stdout) */
153 void
154 shprintf(const char *fmt, ...)
155 {
156 	va_list va;
157 
158 	if (!shl_stdout_ok)
159 		internal_errorf("shl_stdout not valid");
160 	va_start(va, fmt);
161 	shf_vfprintf(shl_stdout, fmt, va);
162 	va_end(va);
163 }
164 
165 #ifdef KSH_DEBUG
166 static struct shf *kshdebug_shf;
167 
168 void
169 kshdebug_init_(void)
170 {
171 	if (kshdebug_shf)
172 		shf_close(kshdebug_shf);
173 	kshdebug_shf = shf_open("/tmp/ksh-debug.log",
174 	    O_WRONLY|O_APPEND|O_CREAT, 0600, SHF_WR|SHF_MAPHI);
175 	if (kshdebug_shf) {
176 		shf_fprintf(kshdebug_shf, "\nNew shell[pid %d]\n", getpid());
177 		shf_flush(kshdebug_shf);
178 	}
179 }
180 
181 /* print to debugging log */
182 void
183 kshdebug_printf_(const char *fmt, ...)
184 {
185 	va_list va;
186 
187 	if (!kshdebug_shf)
188 		return;
189 	va_start(va, fmt);
190 	shf_fprintf(kshdebug_shf, "[%d] ", getpid());
191 	shf_vfprintf(kshdebug_shf, fmt, va);
192 	va_end(va);
193 	shf_flush(kshdebug_shf);
194 }
195 
196 void
197 kshdebug_dump_(const char *str, const void *mem, int nbytes)
198 {
199 	int i, j;
200 	int nprow = 16;
201 
202 	if (!kshdebug_shf)
203 		return;
204 	shf_fprintf(kshdebug_shf, "[%d] %s:\n", getpid(), str);
205 	for (i = 0; i < nbytes; i += nprow) {
206 		char c = '\t';
207 
208 		for (j = 0; j < nprow && i + j < nbytes; j++) {
209 			shf_fprintf(kshdebug_shf, "%c%02x", c,
210 			    ((const unsigned char *) mem)[i + j]);
211 			c = ' ';
212 		}
213 		shf_fprintf(kshdebug_shf, "\n");
214 	}
215 	shf_flush(kshdebug_shf);
216 }
217 #endif /* KSH_DEBUG */
218 
219 /* test if we can seek backwards fd (returns 0 or SHF_UNBUF) */
220 int
221 can_seek(int fd)
222 {
223 	struct stat statb;
224 
225 	return fstat(fd, &statb) == 0 && !S_ISREG(statb.st_mode) ?
226 	    SHF_UNBUF : 0;
227 }
228 
229 struct shf	shf_iob[3];
230 
231 void
232 initio(void)
233 {
234 	shf_fdopen(1, SHF_WR, shl_stdout);	/* force buffer allocation */
235 	shf_fdopen(2, SHF_WR, shl_out);
236 	shf_fdopen(2, SHF_WR, shl_spare);	/* force buffer allocation */
237 	initio_done = 1;
238 	kshdebug_init();
239 }
240 
241 /* A dup2() with error checking */
242 int
243 ksh_dup2(int ofd, int nfd, int errok)
244 {
245 	int ret = dup2(ofd, nfd);
246 
247 	if (ret == -1 && errno != EBADF && !errok)
248 		errorf("too many files open in shell");
249 
250 	return ret;
251 }
252 
253 /*
254  * move fd from user space (0<=fd<10) to shell space (fd>=10),
255  * set close-on-exec flag.
256  */
257 int
258 savefd(int fd)
259 {
260 	int nfd;
261 
262 	if (fd < FDBASE) {
263 		nfd = fcntl(fd, F_DUPFD_CLOEXEC, FDBASE);
264 		if (nfd == -1) {
265 			if (errno == EBADF)
266 				return -1;
267 			else
268 				errorf("too many files open in shell");
269 		}
270 	} else {
271 		nfd = fd;
272 		fcntl(nfd, F_SETFD, FD_CLOEXEC);
273 	}
274 	return nfd;
275 }
276 
277 void
278 restfd(int fd, int ofd)
279 {
280 	if (fd == 2)
281 		shf_flush(&shf_iob[fd]);
282 	if (ofd < 0)		/* original fd closed */
283 		close(fd);
284 	else if (fd != ofd) {
285 		ksh_dup2(ofd, fd, true); /* XXX: what to do if this fails? */
286 		close(ofd);
287 	}
288 }
289 
290 void
291 openpipe(int *pv)
292 {
293 	int lpv[2];
294 
295 	if (pipe(lpv) == -1)
296 		errorf("can't create pipe - try again");
297 	pv[0] = savefd(lpv[0]);
298 	if (pv[0] != lpv[0])
299 		close(lpv[0]);
300 	pv[1] = savefd(lpv[1]);
301 	if (pv[1] != lpv[1])
302 		close(lpv[1]);
303 }
304 
305 void
306 closepipe(int *pv)
307 {
308 	close(pv[0]);
309 	close(pv[1]);
310 }
311 
312 /* Called by iosetup() (deals with 2>&4, etc.), c_read, c_print to turn
313  * a string (the X in 2>&X, read -uX, print -uX) into a file descriptor.
314  */
315 int
316 check_fd(char *name, int mode, const char **emsgp)
317 {
318 	int fd, fl;
319 
320 	if (isdigit((unsigned char)name[0]) && !name[1]) {
321 		fd = name[0] - '0';
322 		if ((fl = fcntl(fd, F_GETFL)) == -1) {
323 			if (emsgp)
324 				*emsgp = "bad file descriptor";
325 			return -1;
326 		}
327 		fl &= O_ACCMODE;
328 		/* X_OK is a kludge to disable this check for dups (x<&1):
329 		 * historical shells never did this check (XXX don't know what
330 		 * posix has to say).
331 		 */
332 		if (!(mode & X_OK) && fl != O_RDWR &&
333 		    (((mode & R_OK) && fl != O_RDONLY) ||
334 		    ((mode & W_OK) && fl != O_WRONLY))) {
335 			if (emsgp)
336 				*emsgp = (fl == O_WRONLY) ?
337 				    "fd not open for reading" :
338 				    "fd not open for writing";
339 			return -1;
340 		}
341 		return fd;
342 	} else if (name[0] == 'p' && !name[1])
343 		return coproc_getfd(mode, emsgp);
344 	if (emsgp)
345 		*emsgp = "illegal file descriptor name";
346 	return -1;
347 }
348 
349 /* Called once from main */
350 void
351 coproc_init(void)
352 {
353 	coproc.read = coproc.readw = coproc.write = -1;
354 	coproc.njobs = 0;
355 	coproc.id = 0;
356 }
357 
358 /* Called by c_read() when eof is read - close fd if it is the co-process fd */
359 void
360 coproc_read_close(int fd)
361 {
362 	if (coproc.read >= 0 && fd == coproc.read) {
363 		coproc_readw_close(fd);
364 		close(coproc.read);
365 		coproc.read = -1;
366 	}
367 }
368 
369 /* Called by c_read() and by iosetup() to close the other side of the
370  * read pipe, so reads will actually terminate.
371  */
372 void
373 coproc_readw_close(int fd)
374 {
375 	if (coproc.readw >= 0 && coproc.read >= 0 && fd == coproc.read) {
376 		close(coproc.readw);
377 		coproc.readw = -1;
378 	}
379 }
380 
381 /* Called by c_print when a write to a fd fails with EPIPE and by iosetup
382  * when co-process input is dup'd
383  */
384 void
385 coproc_write_close(int fd)
386 {
387 	if (coproc.write >= 0 && fd == coproc.write) {
388 		close(coproc.write);
389 		coproc.write = -1;
390 	}
391 }
392 
393 /* Called to check for existence of/value of the co-process file descriptor.
394  * (Used by check_fd() and by c_read/c_print to deal with -p option).
395  */
396 int
397 coproc_getfd(int mode, const char **emsgp)
398 {
399 	int fd = (mode & R_OK) ? coproc.read : coproc.write;
400 
401 	if (fd >= 0)
402 		return fd;
403 	if (emsgp)
404 		*emsgp = "no coprocess";
405 	return -1;
406 }
407 
408 /* called to close file descriptors related to the coprocess (if any)
409  * Should be called with SIGCHLD blocked.
410  */
411 void
412 coproc_cleanup(int reuse)
413 {
414 	/* This to allow co-processes to share output pipe */
415 	if (!reuse || coproc.readw < 0 || coproc.read < 0) {
416 		if (coproc.read >= 0) {
417 			close(coproc.read);
418 			coproc.read = -1;
419 		}
420 		if (coproc.readw >= 0) {
421 			close(coproc.readw);
422 			coproc.readw = -1;
423 		}
424 	}
425 	if (coproc.write >= 0) {
426 		close(coproc.write);
427 		coproc.write = -1;
428 	}
429 }
430 
431 
432 /*
433  * temporary files
434  */
435 
436 struct temp *
437 maketemp(Area *ap, Temp_type type, struct temp **tlist)
438 {
439 	struct temp *tp;
440 	int len;
441 	int fd;
442 	char *path;
443 	const char *dir;
444 
445 	dir = tmpdir ? tmpdir : "/tmp";
446 	/* The 20 + 20 is a paranoid worst case for pid/inc */
447 	len = strlen(dir) + 3 + 20 + 20 + 1;
448 	tp = alloc(sizeof(struct temp) + len, ap);
449 	tp->name = path = (char *) &tp[1];
450 	tp->shf = NULL;
451 	tp->type = type;
452 	shf_snprintf(path, len, "%s/shXXXXXXXX", dir);
453 	fd = mkstemp(path);
454 	if (fd >= 0)
455 		tp->shf = shf_fdopen(fd, SHF_WR, NULL);
456 	tp->pid = procpid;
457 
458 	tp->next = *tlist;
459 	*tlist = tp;
460 	return tp;
461 }
462