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1 /*	$OpenBSD: shf.c,v 1.16 2013/04/19 17:36:09 millert Exp $	*/
2 
3 /*-
4  * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2011,
5  *		 2012, 2013, 2015, 2016, 2017, 2018, 2019
6  *	mirabilos <m@mirbsd.org>
7  * Copyright (c) 2015
8  *	Daniel Richard G. <skunk@iSKUNK.ORG>
9  *
10  * Provided that these terms and disclaimer and all copyright notices
11  * are retained or reproduced in an accompanying document, permission
12  * is granted to deal in this work without restriction, including un-
13  * limited rights to use, publicly perform, distribute, sell, modify,
14  * merge, give away, or sublicence.
15  *
16  * This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
17  * the utmost extent permitted by applicable law, neither express nor
18  * implied; without malicious intent or gross negligence. In no event
19  * may a licensor, author or contributor be held liable for indirect,
20  * direct, other damage, loss, or other issues arising in any way out
21  * of dealing in the work, even if advised of the possibility of such
22  * damage or existence of a defect, except proven that it results out
23  * of said person's immediate fault when using the work as intended.
24  *-
25  * Use %zX instead of %p and floating point isn't supported at all.
26  */
27 
28 #include "sh.h"
29 
30 __RCSID("$MirOS: src/bin/mksh/shf.c,v 1.102 2020/06/22 17:11:03 tg Exp $");
31 
32 /* flags to shf_emptybuf() */
33 #define EB_READSW	0x01	/* about to switch to reading */
34 #define EB_GROW		0x02	/* grow buffer if necessary (STRING+DYNAMIC) */
35 
36 /*
37  * Replacement stdio routines. Stdio is too flakey on too many machines
38  * to be useful when you have multiple processes using the same underlying
39  * file descriptors.
40  */
41 
42 static int shf_fillbuf(struct shf *);
43 static int shf_emptybuf(struct shf *, int);
44 
45 /*
46  * Open a file. First three args are for open(), last arg is flags for
47  * this package. Returns NULL if file could not be opened, or if a dup
48  * fails.
49  */
50 struct shf *
shf_open(const char * name,int oflags,int mode,int sflags)51 shf_open(const char *name, int oflags, int mode, int sflags)
52 {
53 	struct shf *shf;
54 	ssize_t bsize =
55 	    /* at most 512 */
56 	    sflags & SHF_UNBUF ? (sflags & SHF_RD ? 1 : 0) : SHF_BSIZE;
57 	int fd, eno;
58 
59 	/* Done before open so if alloca fails, fd won't be lost. */
60 	shf = alloc(sizeof(struct shf) + bsize, ATEMP);
61 	shf->areap = ATEMP;
62 	shf->buf = (unsigned char *)&shf[1];
63 	shf->bsize = bsize;
64 	shf->flags = SHF_ALLOCS;
65 	/* Rest filled in by reopen. */
66 
67 	fd = binopen3(name, oflags, mode);
68 	if (fd < 0) {
69 		eno = errno;
70 		afree(shf, shf->areap);
71 		errno = eno;
72 		return (NULL);
73 	}
74 	if ((sflags & SHF_MAPHI) && fd < FDBASE) {
75 		int nfd;
76 
77 		nfd = fcntl(fd, F_DUPFD, FDBASE);
78 		eno = errno;
79 		close(fd);
80 		if (nfd < 0) {
81 			afree(shf, shf->areap);
82 			errno = eno;
83 			return (NULL);
84 		}
85 		fd = nfd;
86 	}
87 	sflags &= ~SHF_ACCMODE;
88 	sflags |= (oflags & O_ACCMODE) == O_RDONLY ? SHF_RD :
89 	    ((oflags & O_ACCMODE) == O_WRONLY ? SHF_WR : SHF_RDWR);
90 
91 	return (shf_reopen(fd, sflags, shf));
92 }
93 
94 /* helper function for shf_fdopen and shf_reopen */
95 static void
shf_open_hlp(int fd,int * sflagsp,const char * where)96 shf_open_hlp(int fd, int *sflagsp, const char *where)
97 {
98 	int sflags = *sflagsp;
99 
100 	/* use fcntl() to figure out correct read/write flags */
101 	if (sflags & SHF_GETFL) {
102 		int flags = fcntl(fd, F_GETFL, 0);
103 
104 		if (flags < 0)
105 			/* will get an error on first read/write */
106 			sflags |= SHF_RDWR;
107 		else {
108 			switch (flags & O_ACCMODE) {
109 			case O_RDONLY:
110 				sflags |= SHF_RD;
111 				break;
112 			case O_WRONLY:
113 				sflags |= SHF_WR;
114 				break;
115 			case O_RDWR:
116 				sflags |= SHF_RDWR;
117 				break;
118 			}
119 		}
120 		*sflagsp = sflags;
121 	}
122 
123 	if (!(sflags & (SHF_RD | SHF_WR)))
124 		internal_errorf(Tf_sD_s, where, "missing read/write");
125 }
126 
127 /* Set up the shf structure for a file descriptor. Doesn't fail. */
128 struct shf *
shf_fdopen(int fd,int sflags,struct shf * shf)129 shf_fdopen(int fd, int sflags, struct shf *shf)
130 {
131 	ssize_t bsize =
132 	    /* at most 512 */
133 	    sflags & SHF_UNBUF ? (sflags & SHF_RD ? 1 : 0) : SHF_BSIZE;
134 
135 	shf_open_hlp(fd, &sflags, "shf_fdopen");
136 	if (shf) {
137 		if (bsize) {
138 			shf->buf = alloc(bsize, ATEMP);
139 			sflags |= SHF_ALLOCB;
140 		} else
141 			shf->buf = NULL;
142 	} else {
143 		shf = alloc(sizeof(struct shf) + bsize, ATEMP);
144 		shf->buf = (unsigned char *)&shf[1];
145 		sflags |= SHF_ALLOCS;
146 	}
147 	shf->areap = ATEMP;
148 	shf->fd = fd;
149 	shf->rp = shf->wp = shf->buf;
150 	shf->rnleft = 0;
151 	shf->rbsize = bsize;
152 	shf->wnleft = 0; /* force call to shf_emptybuf() */
153 	shf->wbsize = sflags & SHF_UNBUF ? 0 : bsize;
154 	shf->flags = sflags;
155 	shf->errnosv = 0;
156 	shf->bsize = bsize;
157 	if (sflags & SHF_CLEXEC)
158 		fcntl(fd, F_SETFD, FD_CLOEXEC);
159 	return (shf);
160 }
161 
162 /* Set up an existing shf (and buffer) to use the given fd */
163 struct shf *
shf_reopen(int fd,int sflags,struct shf * shf)164 shf_reopen(int fd, int sflags, struct shf *shf)
165 {
166 	ssize_t bsize =
167 	    /* at most 512 */
168 	    sflags & SHF_UNBUF ? (sflags & SHF_RD ? 1 : 0) : SHF_BSIZE;
169 
170 	shf_open_hlp(fd, &sflags, "shf_reopen");
171 	if (!shf || !shf->buf || shf->bsize < bsize)
172 		internal_errorf(Tf_sD_s, "shf_reopen", Tbad_bsize);
173 
174 	/* assumes shf->buf and shf->bsize already set up */
175 	shf->fd = fd;
176 	shf->rp = shf->wp = shf->buf;
177 	shf->rnleft = 0;
178 	shf->rbsize = bsize;
179 	shf->wnleft = 0; /* force call to shf_emptybuf() */
180 	shf->wbsize = sflags & SHF_UNBUF ? 0 : bsize;
181 	shf->flags = (shf->flags & (SHF_ALLOCS | SHF_ALLOCB)) | sflags;
182 	shf->errnosv = 0;
183 	if (sflags & SHF_CLEXEC)
184 		fcntl(fd, F_SETFD, FD_CLOEXEC);
185 	return (shf);
186 }
187 
188 /*
189  * Open a string for reading or writing. If reading, bsize is the number
190  * of bytes that can be read. If writing, bsize is the maximum number of
191  * bytes that can be written. If shf is not NULL, it is filled in and
192  * returned, if it is NULL, shf is allocated. If writing and buf is NULL
193  * and SHF_DYNAMIC is set, the buffer is allocated (if bsize > 0, it is
194  * used for the initial size). Doesn't fail.
195  * When writing, a byte is reserved for a trailing NUL - see shf_sclose().
196  */
197 struct shf *
shf_sopen(char * buf,ssize_t bsize,int sflags,struct shf * shf)198 shf_sopen(char *buf, ssize_t bsize, int sflags, struct shf *shf)
199 {
200 	/* can't have a read+write string */
201 	if (!(!(sflags & SHF_RD) ^ !(sflags & SHF_WR)))
202 		internal_errorf(Tf_flags, "shf_sopen",
203 		    (unsigned int)sflags);
204 
205 	if (!shf) {
206 		shf = alloc(sizeof(struct shf), ATEMP);
207 		sflags |= SHF_ALLOCS;
208 	}
209 	shf->areap = ATEMP;
210 	if (!buf && (sflags & SHF_WR) && (sflags & SHF_DYNAMIC)) {
211 		if (bsize <= 0)
212 			bsize = 64;
213 		sflags |= SHF_ALLOCB;
214 		buf = alloc(bsize, shf->areap);
215 	}
216 	shf->fd = -1;
217 	shf->buf = shf->rp = shf->wp = (unsigned char *)buf;
218 	shf->rnleft = bsize;
219 	shf->rbsize = bsize;
220 	shf->wnleft = bsize - 1;	/* space for a '\0' */
221 	shf->wbsize = bsize;
222 	shf->flags = sflags | SHF_STRING;
223 	shf->errnosv = 0;
224 	shf->bsize = bsize;
225 
226 	return (shf);
227 }
228 
229 /* Flush and close file descriptor, free the shf structure */
230 int
shf_close(struct shf * shf)231 shf_close(struct shf *shf)
232 {
233 	int ret = 0;
234 
235 	if (shf->fd >= 0) {
236 		ret = shf_flush(shf);
237 		if (close(shf->fd) < 0)
238 			ret = -1;
239 	}
240 	if (shf->flags & SHF_ALLOCS)
241 		afree(shf, shf->areap);
242 	else if (shf->flags & SHF_ALLOCB)
243 		afree(shf->buf, shf->areap);
244 
245 	return (ret);
246 }
247 
248 /* Flush and close file descriptor, don't free file structure */
249 int
shf_fdclose(struct shf * shf)250 shf_fdclose(struct shf *shf)
251 {
252 	int ret = 0;
253 
254 	if (shf->fd >= 0) {
255 		ret = shf_flush(shf);
256 		if (close(shf->fd) < 0)
257 			ret = -1;
258 		shf->rnleft = 0;
259 		shf->rp = shf->buf;
260 		shf->wnleft = 0;
261 		shf->fd = -1;
262 	}
263 
264 	return (ret);
265 }
266 
267 /*
268  * Close a string - if it was opened for writing, it is NUL terminated;
269  * returns a pointer to the string and frees shf if it was allocated
270  * (does not free string if it was allocated).
271  */
272 char *
shf_sclose(struct shf * shf)273 shf_sclose(struct shf *shf)
274 {
275 	unsigned char *s = shf->buf;
276 
277 	/* NUL terminate */
278 	if (shf->flags & SHF_WR) {
279 		shf->wnleft++;
280 		shf_putc('\0', shf);
281 	}
282 	if (shf->flags & SHF_ALLOCS)
283 		afree(shf, shf->areap);
284 	return ((char *)s);
285 }
286 
287 /*
288  * Un-read what has been read but not examined, or write what has been
289  * buffered. Returns 0 for success, -1 for (write) error.
290  */
291 int
shf_flush(struct shf * shf)292 shf_flush(struct shf *shf)
293 {
294 	int rv = 0;
295 
296 	if (shf->flags & SHF_STRING)
297 		rv = (shf->flags & SHF_WR) ? -1 : 0;
298 	else if (shf->fd < 0)
299 		internal_errorf(Tf_sD_s, "shf_flush", "no fd");
300 	else if (shf->flags & SHF_ERROR) {
301 		errno = shf->errnosv;
302 		rv = -1;
303 	} else if (shf->flags & SHF_READING) {
304 		shf->flags &= ~(SHF_EOF | SHF_READING);
305 		if (shf->rnleft > 0) {
306 			if (lseek(shf->fd, (off_t)-shf->rnleft,
307 			    SEEK_CUR) == -1) {
308 				shf->flags |= SHF_ERROR;
309 				shf->errnosv = errno;
310 				rv = -1;
311 			}
312 			shf->rnleft = 0;
313 			shf->rp = shf->buf;
314 		}
315 	} else if (shf->flags & SHF_WRITING)
316 		rv = shf_emptybuf(shf, 0);
317 
318 	return (rv);
319 }
320 
321 /*
322  * Write out any buffered data. If currently reading, flushes the read
323  * buffer. Returns 0 for success, -1 for (write) error.
324  */
325 static int
shf_emptybuf(struct shf * shf,int flags)326 shf_emptybuf(struct shf *shf, int flags)
327 {
328 	int ret = 0;
329 
330 	if (!(shf->flags & SHF_STRING) && shf->fd < 0)
331 		internal_errorf(Tf_sD_s, "shf_emptybuf", "no fd");
332 
333 	if (shf->flags & SHF_ERROR) {
334 		errno = shf->errnosv;
335 		return (-1);
336 	}
337 
338 	if (shf->flags & SHF_READING) {
339 		if (flags & EB_READSW)
340 			/* doesn't happen */
341 			return (0);
342 		ret = shf_flush(shf);
343 		shf->flags &= ~SHF_READING;
344 	}
345 	if (shf->flags & SHF_STRING) {
346 		unsigned char *nbuf;
347 
348 		/*
349 		 * Note that we assume SHF_ALLOCS is not set if
350 		 * SHF_ALLOCB is set... (changing the shf pointer could
351 		 * cause problems)
352 		 */
353 		if (!(flags & EB_GROW) || !(shf->flags & SHF_DYNAMIC) ||
354 		    !(shf->flags & SHF_ALLOCB))
355 			return (-1);
356 		/* allocate more space for buffer */
357 		nbuf = aresize2(shf->buf, 2, shf->wbsize, shf->areap);
358 		shf->rp = nbuf + (shf->rp - shf->buf);
359 		shf->wp = nbuf + (shf->wp - shf->buf);
360 		shf->rbsize += shf->wbsize;
361 		shf->wnleft += shf->wbsize;
362 		shf->wbsize <<= 1;
363 		shf->buf = nbuf;
364 	} else {
365 		if (shf->flags & SHF_WRITING) {
366 			ssize_t n, ntowrite = shf->wp - shf->buf;
367 			unsigned char *buf = shf->buf;
368 
369 			while (ntowrite > 0) {
370 				n = write(shf->fd, buf, ntowrite);
371 				if (n < 0) {
372 					if (errno == EINTR &&
373 					    !(shf->flags & SHF_INTERRUPT))
374 						continue;
375 					shf->flags |= SHF_ERROR;
376 					shf->errnosv = errno;
377 					shf->wnleft = 0;
378 					if (buf != shf->buf) {
379 						/*
380 						 * allow a second flush
381 						 * to work
382 						 */
383 						memmove(shf->buf, buf,
384 						    ntowrite);
385 						shf->wp = shf->buf + ntowrite;
386 					}
387 					return (-1);
388 				}
389 				buf += n;
390 				ntowrite -= n;
391 			}
392 			if (flags & EB_READSW) {
393 				shf->wp = shf->buf;
394 				shf->wnleft = 0;
395 				shf->flags &= ~SHF_WRITING;
396 				return (0);
397 			}
398 		}
399 		shf->wp = shf->buf;
400 		shf->wnleft = shf->wbsize;
401 	}
402 	shf->flags |= SHF_WRITING;
403 
404 	return (ret);
405 }
406 
407 /* Fill up a read buffer. Returns -1 for a read error, 0 otherwise. */
408 static int
shf_fillbuf(struct shf * shf)409 shf_fillbuf(struct shf *shf)
410 {
411 	ssize_t n;
412 
413 	if (shf->flags & SHF_STRING)
414 		return (0);
415 
416 	if (shf->fd < 0)
417 		internal_errorf(Tf_sD_s, "shf_fillbuf", "no fd");
418 
419 	if (shf->flags & (SHF_EOF | SHF_ERROR)) {
420 		if (shf->flags & SHF_ERROR)
421 			errno = shf->errnosv;
422 		return (-1);
423 	}
424 
425 	if ((shf->flags & SHF_WRITING) && shf_emptybuf(shf, EB_READSW) == -1)
426 		return (-1);
427 
428 	shf->flags |= SHF_READING;
429 
430 	shf->rp = shf->buf;
431 	while (/* CONSTCOND */ 1) {
432 		n = blocking_read(shf->fd, (char *)shf->buf, shf->rbsize);
433 		if (n < 0 && errno == EINTR && !(shf->flags & SHF_INTERRUPT))
434 			continue;
435 		break;
436 	}
437 	if (n < 0) {
438 		shf->flags |= SHF_ERROR;
439 		shf->errnosv = errno;
440 		shf->rnleft = 0;
441 		shf->rp = shf->buf;
442 		return (-1);
443 	}
444 	if ((shf->rnleft = n) == 0)
445 		shf->flags |= SHF_EOF;
446 	return (0);
447 }
448 
449 /*
450  * Read a buffer from shf. Returns the number of bytes read into buf, if
451  * no bytes were read, returns 0 if end of file was seen, -1 if a read
452  * error occurred.
453  */
454 ssize_t
shf_read(char * buf,ssize_t bsize,struct shf * shf)455 shf_read(char *buf, ssize_t bsize, struct shf *shf)
456 {
457 	ssize_t ncopy, orig_bsize = bsize;
458 
459 	if (!(shf->flags & SHF_RD))
460 		internal_errorf(Tf_flags, Tshf_read,
461 		    (unsigned int)shf->flags);
462 
463 	if (bsize <= 0)
464 		internal_errorf(Tf_szs, Tshf_read, bsize, Tbsize);
465 
466 	while (bsize > 0) {
467 		if (shf->rnleft == 0 &&
468 		    (shf_fillbuf(shf) == -1 || shf->rnleft == 0))
469 			break;
470 		ncopy = shf->rnleft;
471 		if (ncopy > bsize)
472 			ncopy = bsize;
473 		memcpy(buf, shf->rp, ncopy);
474 		buf += ncopy;
475 		bsize -= ncopy;
476 		shf->rp += ncopy;
477 		shf->rnleft -= ncopy;
478 	}
479 	/* Note: fread(3S) returns 0 for errors - this doesn't */
480 	return (orig_bsize == bsize ? (shf_error(shf) ? -1 : 0) :
481 	    orig_bsize - bsize);
482 }
483 
484 /*
485  * Read up to a newline or -1. The newline is put in buf; buf is always
486  * NUL terminated. Returns NULL on read error or if nothing was read
487  * before end of file, returns a pointer to the NUL byte in buf
488  * otherwise.
489  */
490 char *
shf_getse(char * buf,ssize_t bsize,struct shf * shf)491 shf_getse(char *buf, ssize_t bsize, struct shf *shf)
492 {
493 	unsigned char *end;
494 	ssize_t ncopy;
495 	char *orig_buf = buf;
496 
497 	if (!(shf->flags & SHF_RD))
498 		internal_errorf(Tf_flags, "shf_getse",
499 		    (unsigned int)shf->flags);
500 
501 	if (bsize <= 0)
502 		return (NULL);
503 
504 	/* save room for NUL */
505 	--bsize;
506 	do {
507 		if (shf->rnleft == 0) {
508 			if (shf_fillbuf(shf) == -1)
509 				return (NULL);
510 			if (shf->rnleft == 0) {
511 				*buf = '\0';
512 				return (buf == orig_buf ? NULL : buf);
513 			}
514 		}
515 		end = (unsigned char *)memchr((char *)shf->rp, '\n',
516 		    shf->rnleft);
517 		ncopy = end ? end - shf->rp + 1 : shf->rnleft;
518 		if (ncopy > bsize)
519 			ncopy = bsize;
520 		memcpy(buf, (char *) shf->rp, ncopy);
521 		shf->rp += ncopy;
522 		shf->rnleft -= ncopy;
523 		buf += ncopy;
524 		bsize -= ncopy;
525 #ifdef MKSH_WITH_TEXTMODE
526 		if (buf > orig_buf + 1 && ord(buf[-2]) == ORD('\r') &&
527 		    ord(buf[-1]) == ORD('\n')) {
528 			buf--;
529 			bsize++;
530 			buf[-1] = '\n';
531 		}
532 #endif
533 	} while (!end && bsize);
534 #ifdef MKSH_WITH_TEXTMODE
535 	if (!bsize && ord(buf[-1]) == ORD('\r')) {
536 		int c = shf_getc(shf);
537 		if (ord(c) == ORD('\n'))
538 			buf[-1] = '\n';
539 		else if (c != -1)
540 			shf_ungetc(c, shf);
541 	}
542 #endif
543 	*buf = '\0';
544 	return (buf);
545 }
546 
547 /* Returns the char read. Returns -1 for error and end of file. */
548 int
shf_getchar(struct shf * shf)549 shf_getchar(struct shf *shf)
550 {
551 	if (!(shf->flags & SHF_RD))
552 		internal_errorf(Tf_flags, "shf_getchar",
553 		    (unsigned int)shf->flags);
554 
555 	if (shf->rnleft == 0 && (shf_fillbuf(shf) == -1 || shf->rnleft == 0))
556 		return (-1);
557 	--shf->rnleft;
558 	return (ord(*shf->rp++));
559 }
560 
561 /*
562  * Put a character back in the input stream. Returns the character if
563  * successful, -1 if there is no room.
564  */
565 int
shf_ungetc(int c,struct shf * shf)566 shf_ungetc(int c, struct shf *shf)
567 {
568 	if (!(shf->flags & SHF_RD))
569 		internal_errorf(Tf_flags, "shf_ungetc",
570 		    (unsigned int)shf->flags);
571 
572 	if ((shf->flags & SHF_ERROR) || c == -1 ||
573 	    (shf->rp == shf->buf && shf->rnleft))
574 		return (-1);
575 
576 	if ((shf->flags & SHF_WRITING) && shf_emptybuf(shf, EB_READSW) == -1)
577 		return (-1);
578 
579 	if (shf->rp == shf->buf)
580 		shf->rp = shf->buf + shf->rbsize;
581 	if (shf->flags & SHF_STRING) {
582 		/*
583 		 * Can unget what was read, but not something different;
584 		 * we don't want to modify a string.
585 		 */
586 		if ((int)(shf->rp[-1]) != c)
587 			return (-1);
588 		shf->flags &= ~SHF_EOF;
589 		shf->rp--;
590 		shf->rnleft++;
591 		return (c);
592 	}
593 	shf->flags &= ~SHF_EOF;
594 	*--(shf->rp) = c;
595 	shf->rnleft++;
596 	return (c);
597 }
598 
599 /*
600  * Write a character. Returns the character if successful, -1 if the
601  * char could not be written.
602  */
603 int
shf_putchar(int c,struct shf * shf)604 shf_putchar(int c, struct shf *shf)
605 {
606 	if (!(shf->flags & SHF_WR))
607 		internal_errorf(Tf_flags, "shf_putchar",
608 		    (unsigned int)shf->flags);
609 
610 	if (c == -1)
611 		return (-1);
612 
613 	if (shf->flags & SHF_UNBUF) {
614 		unsigned char cc = (unsigned char)c;
615 		ssize_t n;
616 
617 		if (shf->fd < 0)
618 			internal_errorf(Tf_sD_s, "shf_putchar", "no fd");
619 		if (shf->flags & SHF_ERROR) {
620 			errno = shf->errnosv;
621 			return (-1);
622 		}
623 		while ((n = write(shf->fd, &cc, 1)) != 1)
624 			if (n < 0) {
625 				if (errno == EINTR &&
626 				    !(shf->flags & SHF_INTERRUPT))
627 					continue;
628 				shf->flags |= SHF_ERROR;
629 				shf->errnosv = errno;
630 				return (-1);
631 			}
632 	} else {
633 		/* Flush deals with strings and sticky errors */
634 		if (shf->wnleft == 0 && shf_emptybuf(shf, EB_GROW) == -1)
635 			return (-1);
636 		shf->wnleft--;
637 		*shf->wp++ = c;
638 	}
639 
640 	return (c);
641 }
642 
643 /*
644  * Write a string. Returns the length of the string if successful, -1
645  * if the string could not be written.
646  */
647 ssize_t
shf_puts(const char * s,struct shf * shf)648 shf_puts(const char *s, struct shf *shf)
649 {
650 	if (!s)
651 		return (-1);
652 
653 	return (shf_write(s, strlen(s), shf));
654 }
655 
656 /* Write a buffer. Returns nbytes if successful, -1 if there is an error. */
657 ssize_t
shf_write(const char * buf,ssize_t nbytes,struct shf * shf)658 shf_write(const char *buf, ssize_t nbytes, struct shf *shf)
659 {
660 	ssize_t n, ncopy, orig_nbytes = nbytes;
661 
662 	if (!(shf->flags & SHF_WR))
663 		internal_errorf(Tf_flags, Tshf_write,
664 		    (unsigned int)shf->flags);
665 
666 	if (nbytes < 0)
667 		internal_errorf(Tf_szs, Tshf_write, nbytes, Tbytes);
668 
669 	/* don't buffer if buffer is empty and we're writing a large amount */
670 	if ((ncopy = shf->wnleft) &&
671 	    (shf->wp != shf->buf || nbytes < shf->wnleft)) {
672 		if (ncopy > nbytes)
673 			ncopy = nbytes;
674 		memcpy(shf->wp, buf, ncopy);
675 		nbytes -= ncopy;
676 		buf += ncopy;
677 		shf->wp += ncopy;
678 		shf->wnleft -= ncopy;
679 	}
680 	if (nbytes > 0) {
681 		if (shf->flags & SHF_STRING) {
682 			/* resize buffer until there's enough space left */
683 			while (nbytes > shf->wnleft)
684 				if (shf_emptybuf(shf, EB_GROW) == -1)
685 					return (-1);
686 			/* then write everything into the buffer */
687 		} else {
688 			/* flush deals with sticky errors */
689 			if (shf_emptybuf(shf, EB_GROW) == -1)
690 				return (-1);
691 			/* write chunks larger than window size directly */
692 			if (nbytes > shf->wbsize) {
693 				ncopy = nbytes;
694 				if (shf->wbsize)
695 					ncopy -= nbytes % shf->wbsize;
696 				nbytes -= ncopy;
697 				while (ncopy > 0) {
698 					n = write(shf->fd, buf, ncopy);
699 					if (n < 0) {
700 						if (errno == EINTR &&
701 						    !(shf->flags & SHF_INTERRUPT))
702 							continue;
703 						shf->flags |= SHF_ERROR;
704 						shf->errnosv = errno;
705 						shf->wnleft = 0;
706 						/*
707 						 * Note: fwrite(3) returns 0
708 						 * for errors - this doesn't
709 						 */
710 						return (-1);
711 					}
712 					buf += n;
713 					ncopy -= n;
714 				}
715 			}
716 			/* ... and buffer the rest */
717 		}
718 		if (nbytes > 0) {
719 			/* write remaining bytes to buffer */
720 			memcpy(shf->wp, buf, nbytes);
721 			shf->wp += nbytes;
722 			shf->wnleft -= nbytes;
723 		}
724 	}
725 
726 	return (orig_nbytes);
727 }
728 
729 ssize_t
shf_fprintf(struct shf * shf,const char * fmt,...)730 shf_fprintf(struct shf *shf, const char *fmt, ...)
731 {
732 	va_list args;
733 	ssize_t n;
734 
735 	va_start(args, fmt);
736 	n = shf_vfprintf(shf, fmt, args);
737 	va_end(args);
738 
739 	return (n);
740 }
741 
742 ssize_t
shf_snprintf(char * buf,ssize_t bsize,const char * fmt,...)743 shf_snprintf(char *buf, ssize_t bsize, const char *fmt, ...)
744 {
745 	struct shf shf;
746 	va_list args;
747 	ssize_t n;
748 
749 	if (!buf || bsize <= 0)
750 		internal_errorf("shf_snprintf: buf %zX, bsize %zd",
751 		    (size_t)buf, bsize);
752 
753 	shf_sopen(buf, bsize, SHF_WR, &shf);
754 	va_start(args, fmt);
755 	n = shf_vfprintf(&shf, fmt, args);
756 	va_end(args);
757 	/* NUL terminates */
758 	shf_sclose(&shf);
759 	return (n);
760 }
761 
762 char *
shf_smprintf(const char * fmt,...)763 shf_smprintf(const char *fmt, ...)
764 {
765 	struct shf shf;
766 	va_list args;
767 
768 	shf_sopen(NULL, 0, SHF_WR|SHF_DYNAMIC, &shf);
769 	va_start(args, fmt);
770 	shf_vfprintf(&shf, fmt, args);
771 	va_end(args);
772 	/* NUL terminates */
773 	return (shf_sclose(&shf));
774 }
775 
776 #define	FL_HASH		0x001	/* '#' seen */
777 #define FL_PLUS		0x002	/* '+' seen */
778 #define FL_RIGHT	0x004	/* '-' seen */
779 #define FL_BLANK	0x008	/* ' ' seen */
780 #define FL_SHORT	0x010	/* 'h' seen */
781 #define FL_LONG		0x020	/* 'l' seen */
782 #define FL_ZERO		0x040	/* '0' seen */
783 #define FL_DOT		0x080	/* '.' seen */
784 #define FL_UPPER	0x100	/* format character was uppercase */
785 #define FL_NUMBER	0x200	/* a number was formatted %[douxefg] */
786 #define FL_SIZET	0x400	/* 'z' seen */
787 #define FM_SIZES	0x430	/* h/l/z mask */
788 
789 ssize_t
shf_vfprintf(struct shf * shf,const char * fmt,va_list args)790 shf_vfprintf(struct shf *shf, const char *fmt, va_list args)
791 {
792 	const char *s;
793 	char c, *cp;
794 	int tmp = 0, flags;
795 	size_t field, precision, len;
796 	unsigned long lnum;
797 	/* %#o produces the longest output */
798 	char numbuf[(8 * sizeof(long) + 2) / 3 + 1 + /* NUL */ 1];
799 	/* this stuff for dealing with the buffer */
800 	ssize_t nwritten = 0;
801 
802 #define VA(type) va_arg(args, type)
803 
804 	if (!fmt)
805 		return (0);
806 
807 	while ((c = *fmt++)) {
808 		if (c != '%') {
809 			shf_putc(c, shf);
810 			nwritten++;
811 			continue;
812 		}
813 		/*
814 		 * This will accept flags/fields in any order - not just
815 		 * the order specified in printf(3), but this is the way
816 		 * _doprnt() seems to work (on BSD and SYSV). The only
817 		 * restriction is that the format character must come
818 		 * last :-).
819 		 */
820 		flags = 0;
821 		field = precision = 0;
822 		while ((c = *fmt++)) {
823 			switch (c) {
824 			case '#':
825 				flags |= FL_HASH;
826 				continue;
827 
828 			case '+':
829 				flags |= FL_PLUS;
830 				continue;
831 
832 			case '-':
833 				flags |= FL_RIGHT;
834 				continue;
835 
836 			case ' ':
837 				flags |= FL_BLANK;
838 				continue;
839 
840 			case '0':
841 				if (!(flags & FL_DOT))
842 					flags |= FL_ZERO;
843 				continue;
844 
845 			case '.':
846 				flags |= FL_DOT;
847 				precision = 0;
848 				continue;
849 
850 			case '*':
851 				tmp = VA(int);
852 				if (tmp < 0) {
853 					if (flags & FL_DOT)
854 						precision = 0;
855 					else {
856 						field = (unsigned int)-tmp;
857 						flags |= FL_RIGHT;
858 					}
859 				} else if (flags & FL_DOT)
860 					precision = (unsigned int)tmp;
861 				else
862 					field = (unsigned int)tmp;
863 				continue;
864 
865 			case 'l':
866 				flags &= ~FM_SIZES;
867 				flags |= FL_LONG;
868 				continue;
869 
870 			case 'h':
871 				flags &= ~FM_SIZES;
872 				flags |= FL_SHORT;
873 				continue;
874 
875 			case 'z':
876 				flags &= ~FM_SIZES;
877 				flags |= FL_SIZET;
878 				continue;
879 			}
880 			if (ctype(c, C_DIGIT)) {
881 				bool overflowed = false;
882 
883 				tmp = ksh_numdig(c);
884 				while (ctype((c = *fmt++), C_DIGIT))
885 					if (notok2mul(2147483647, tmp, 10))
886 						overflowed = true;
887 					else
888 						tmp = tmp * 10 + ksh_numdig(c);
889 				--fmt;
890 				if (overflowed)
891 					tmp = 0;
892 				if (flags & FL_DOT)
893 					precision = (unsigned int)tmp;
894 				else
895 					field = (unsigned int)tmp;
896 				continue;
897 			}
898 			break;
899 		}
900 
901 		if (!c)
902 			/* nasty format */
903 			break;
904 
905 		if (ctype(c, C_UPPER)) {
906 			flags |= FL_UPPER;
907 			c = ksh_tolower(c);
908 		}
909 
910 		switch (c) {
911 		case 'd':
912 		case 'i':
913 			if (flags & FL_SIZET)
914 				lnum = (long)VA(ssize_t);
915 			else if (flags & FL_LONG)
916 				lnum = VA(long);
917 			else if (flags & FL_SHORT)
918 				lnum = (long)(short)VA(int);
919 			else
920 				lnum = (long)VA(int);
921 			goto integral;
922 
923 		case 'o':
924 		case 'u':
925 		case 'x':
926 			if (flags & FL_SIZET)
927 				lnum = VA(size_t);
928 			else if (flags & FL_LONG)
929 				lnum = VA(unsigned long);
930 			else if (flags & FL_SHORT)
931 				lnum = (unsigned long)(unsigned short)VA(int);
932 			else
933 				lnum = (unsigned long)VA(unsigned int);
934 
935  integral:
936 			flags |= FL_NUMBER;
937 			cp = numbuf + sizeof(numbuf);
938 			*--cp = '\0';
939 
940 			switch (c) {
941 			case 'd':
942 			case 'i':
943 				if (0 > (long)lnum) {
944 					lnum = -(long)lnum;
945 					tmp = 1;
946 				} else
947 					tmp = 0;
948 				/* FALLTHROUGH */
949 			case 'u':
950 				do {
951 					*--cp = digits_lc[lnum % 10];
952 					lnum /= 10;
953 				} while (lnum);
954 
955 				if (c != 'u') {
956 					if (tmp)
957 						*--cp = '-';
958 					else if (flags & FL_PLUS)
959 						*--cp = '+';
960 					else if (flags & FL_BLANK)
961 						*--cp = ' ';
962 				}
963 				break;
964 
965 			case 'o':
966 				do {
967 					*--cp = digits_lc[lnum & 0x7];
968 					lnum >>= 3;
969 				} while (lnum);
970 
971 				if ((flags & FL_HASH) && *cp != '0')
972 					*--cp = '0';
973 				break;
974 
975 			case 'x': {
976 				const char *digits = (flags & FL_UPPER) ?
977 				    digits_uc : digits_lc;
978 				do {
979 					*--cp = digits[lnum & 0xF];
980 					lnum >>= 4;
981 				} while (lnum);
982 
983 				if (flags & FL_HASH) {
984 					*--cp = (flags & FL_UPPER) ? 'X' : 'x';
985 					*--cp = '0';
986 				}
987 			    }
988 			}
989 			len = numbuf + sizeof(numbuf) - 1 - (s = cp);
990 			if (flags & FL_DOT) {
991 				if (precision > len) {
992 					field = precision;
993 					flags |= FL_ZERO;
994 				} else
995 					/* no loss */
996 					precision = len;
997 			}
998 			break;
999 
1000 		case 's':
1001 			if ((s = VA(const char *)) == NULL)
1002 				s = "(null)";
1003 			else if (flags & FL_HASH) {
1004 				print_value_quoted(shf, s);
1005 				continue;
1006 			}
1007 			len = utf_mbswidth(s);
1008 			break;
1009 
1010 		case 'c':
1011 			flags &= ~FL_DOT;
1012 			c = (char)(VA(int));
1013 			/* FALLTHROUGH */
1014 
1015 		case '%':
1016 		default:
1017 			numbuf[0] = c;
1018 			numbuf[1] = 0;
1019 			s = numbuf;
1020 			len = 1;
1021 			break;
1022 		}
1023 
1024 		/*
1025 		 * At this point s should point to a string that is to be
1026 		 * formatted, and len should be the length of the string.
1027 		 */
1028 		if (!(flags & FL_DOT) || len < precision)
1029 			precision = len;
1030 		if (field > precision) {
1031 			field -= precision;
1032 			if (!(flags & FL_RIGHT)) {
1033 				/* skip past sign or 0x when padding with 0 */
1034 				if ((flags & FL_ZERO) && (flags & FL_NUMBER)) {
1035 					if (ctype(*s, C_SPC | C_PLUS | C_MINUS)) {
1036 						shf_putc(*s, shf);
1037 						s++;
1038 						precision--;
1039 						nwritten++;
1040 					} else if (*s == '0') {
1041 						shf_putc(*s, shf);
1042 						s++;
1043 						nwritten++;
1044 						if (--precision &&
1045 						    ksh_eq(*s, 'X', 'x')) {
1046 							shf_putc(*s, shf);
1047 							s++;
1048 							precision--;
1049 							nwritten++;
1050 						}
1051 					}
1052 					c = '0';
1053 				} else
1054 					c = flags & FL_ZERO ? '0' : ' ';
1055 				nwritten += field;
1056 				while (field--)
1057 					shf_putc(c, shf);
1058 				field = 0;
1059 			} else
1060 				c = ' ';
1061 		} else
1062 			field = 0;
1063 
1064 		nwritten += precision;
1065 		precision = utf_skipcols(s, precision, &tmp) - s;
1066 		while (precision--)
1067 			shf_putc(*s++, shf);
1068 
1069 		nwritten += field;
1070 		while (field--)
1071 			shf_putc(c, shf);
1072 	}
1073 
1074 	return (shf_error(shf) ? -1 : nwritten);
1075 }
1076 
1077 #ifdef MKSH_SHF_NO_INLINE
1078 int
shf_getc(struct shf * shf)1079 shf_getc(struct shf *shf)
1080 {
1081 	return (shf_getc_i(shf));
1082 }
1083 
1084 int
shf_putc(int c,struct shf * shf)1085 shf_putc(int c, struct shf *shf)
1086 {
1087 	return (shf_putc_i(c, shf));
1088 }
1089 #endif
1090 
1091 #ifdef DEBUG
1092 const char *
cstrerror(int errnum)1093 cstrerror(int errnum)
1094 {
1095 #undef strerror
1096 	return (strerror(errnum));
1097 #define strerror dontuse_strerror /* poisoned */
1098 }
1099 #elif !HAVE_STRERROR
1100 
1101 #if HAVE_SYS_ERRLIST
1102 #if !HAVE_SYS_ERRLIST_DECL
1103 extern const int sys_nerr;
1104 extern const char * const sys_errlist[];
1105 #endif
1106 #endif
1107 
1108 const char *
cstrerror(int errnum)1109 cstrerror(int errnum)
1110 {
1111 	/* "Unknown error: " + sign + rough estimate + NUL */
1112 	static char errbuf[15 + 1 + (8 * sizeof(int) + 2) / 3 + 1];
1113 
1114 #if HAVE_SYS_ERRLIST
1115 	if (errnum > 0 && errnum < sys_nerr && sys_errlist[errnum])
1116 		return (sys_errlist[errnum]);
1117 #endif
1118 
1119 	switch (errnum) {
1120 	case 0:
1121 		return ("Undefined error: 0");
1122 	case EPERM:
1123 		return ("Operation not permitted");
1124 	case ENOENT:
1125 		return ("No such file or directory");
1126 #ifdef ESRCH
1127 	case ESRCH:
1128 		return ("No such process");
1129 #endif
1130 #ifdef E2BIG
1131 	case E2BIG:
1132 		return ("Argument list too long");
1133 #endif
1134 	case ENOEXEC:
1135 		return ("Exec format error");
1136 	case EBADF:
1137 		return ("Bad file descriptor");
1138 #ifdef ENOMEM
1139 	case ENOMEM:
1140 		return ("Cannot allocate memory");
1141 #endif
1142 	case EACCES:
1143 		return ("Permission denied");
1144 	case EEXIST:
1145 		return ("File exists");
1146 	case ENOTDIR:
1147 		return ("Not a directory");
1148 #ifdef EINVAL
1149 	case EINVAL:
1150 		return ("Invalid argument");
1151 #endif
1152 #ifdef ELOOP
1153 	case ELOOP:
1154 		return ("Too many levels of symbolic links");
1155 #endif
1156 	default:
1157 		shf_snprintf(errbuf, sizeof(errbuf),
1158 		    "Unknown error: %d", errnum);
1159 		return (errbuf);
1160 	}
1161 }
1162 #endif
1163 
1164 /* fast character classes */
1165 const uint32_t tpl_ctypes[128] = {
1166 	/* 0x00 */
1167 	CiNUL,		CiCNTRL,	CiCNTRL,	CiCNTRL,
1168 	CiCNTRL,	CiCNTRL,	CiCNTRL,	CiCNTRL,
1169 	CiCNTRL,	CiTAB,		CiNL,		CiSPX,
1170 	CiSPX,		CiCR,		CiCNTRL,	CiCNTRL,
1171 	/* 0x10 */
1172 	CiCNTRL,	CiCNTRL,	CiCNTRL,	CiCNTRL,
1173 	CiCNTRL,	CiCNTRL,	CiCNTRL,	CiCNTRL,
1174 	CiCNTRL,	CiCNTRL,	CiCNTRL,	CiCNTRL,
1175 	CiCNTRL,	CiCNTRL,	CiCNTRL,	CiCNTRL,
1176 	/* 0x20 */
1177 	CiSP,		CiALIAS | CiVAR1,	CiQC,	CiHASH,
1178 	CiSS,		CiPERCT,	CiQCL,		CiQC,
1179 	CiQCL,		CiQCL,		CiQCX | CiVAR1,	CiPLUS,
1180 	CiALIAS,	CiMINUS,	CiALIAS,	CiQCM,
1181 	/* 0x30 */
1182 	CiOCTAL,	CiOCTAL,	CiOCTAL,	CiOCTAL,
1183 	CiOCTAL,	CiOCTAL,	CiOCTAL,	CiOCTAL,
1184 	CiDIGIT,	CiDIGIT,	CiCOLON,	CiQCL,
1185 	CiANGLE,	CiEQUAL,	CiANGLE,	CiQUEST,
1186 	/* 0x40 */
1187 	CiALIAS | CiVAR1,	CiUPPER | CiHEXLT,
1188 	CiUPPER | CiHEXLT,	CiUPPER | CiHEXLT,
1189 	CiUPPER | CiHEXLT,	CiUPPER | CiHEXLT,
1190 	CiUPPER | CiHEXLT,	CiUPPER,
1191 	CiUPPER,	CiUPPER,	CiUPPER,	CiUPPER,
1192 	CiUPPER,	CiUPPER,	CiUPPER,	CiUPPER,
1193 	/* 0x50 */
1194 	CiUPPER,	CiUPPER,	CiUPPER,	CiUPPER,
1195 	CiUPPER,	CiUPPER,	CiUPPER,	CiUPPER,
1196 	CiUPPER,	CiUPPER,	CiUPPER,	CiQCX | CiBRACK,
1197 	CiQCX,		CiBRACK,	CiQCM,		CiUNDER,
1198 	/* 0x60 */
1199 	CiGRAVE,		CiLOWER | CiHEXLT,
1200 	CiLOWER | CiHEXLT,	CiLOWER | CiHEXLT,
1201 	CiLOWER | CiHEXLT,	CiLOWER | CiHEXLT,
1202 	CiLOWER | CiHEXLT,	CiLOWER,
1203 	CiLOWER,	CiLOWER,	CiLOWER,	CiLOWER,
1204 	CiLOWER,	CiLOWER,	CiLOWER,	CiLOWER,
1205 	/* 0x70 */
1206 	CiLOWER,	CiLOWER,	CiLOWER,	CiLOWER,
1207 	CiLOWER,	CiLOWER,	CiLOWER,	CiLOWER,
1208 	CiLOWER,	CiLOWER,	CiLOWER,	CiCURLY,
1209 	CiQCL,		CiCURLY,	CiQCM,		CiCNTRL
1210 };
1211 
1212 void
set_ifs(const char * s)1213 set_ifs(const char *s)
1214 {
1215 #if defined(MKSH_EBCDIC) || defined(MKSH_FAUX_EBCDIC)
1216 	int i = 256;
1217 
1218 	memset(ksh_ctypes, 0, sizeof(ksh_ctypes));
1219 	while (i--)
1220 		if (ebcdic_map[i] < 0x80U)
1221 			ksh_ctypes[i] = tpl_ctypes[ebcdic_map[i]];
1222 #else
1223 	memcpy(ksh_ctypes, tpl_ctypes, sizeof(tpl_ctypes));
1224 	memset((char *)ksh_ctypes + sizeof(tpl_ctypes), '\0',
1225 	    sizeof(ksh_ctypes) - sizeof(tpl_ctypes));
1226 #endif
1227 	ifs0 = *s;
1228 	while (*s)
1229 		ksh_ctypes[ord(*s++)] |= CiIFS;
1230 }
1231 
1232 #if defined(MKSH_EBCDIC) || defined(MKSH_FAUX_EBCDIC)
1233 #include <locale.h>
1234 
1235 /*
1236  * Many headaches with EBCDIC:
1237  * 1. There are numerous EBCDIC variants, and it is not feasible for us
1238  *    to support them all. But we can support the EBCDIC code pages that
1239  *    contain all (most?) of the characters in ASCII, and these
1240  *    usually tend to agree on the code points assigned to the ASCII
1241  *    subset. If you need a representative example, look at EBCDIC 1047,
1242  *    which is first among equals in the IBM MVS development
1243  *    environment: https://en.wikipedia.org/wiki/EBCDIC_1047
1244  *    Unfortunately, the square brackets are not consistently mapped,
1245  *    and for certain reasons, we need an unambiguous bijective
1246  *    mapping between EBCDIC and "extended ASCII".
1247  * 2. Character ranges that are contiguous in ASCII, like the letters
1248  *    in [A-Z], are broken up into segments (i.e. [A-IJ-RS-Z]), so we
1249  *    can't implement e.g. islower() as { return c >= 'a' && c <= 'z'; }
1250  *    because it will also return true for a handful of extraneous
1251  *    characters (like the plus-minus sign at 0x8F in EBCDIC 1047, a
1252  *    little after 'i'). But at least '_' is not one of these.
1253  * 3. The normal [0-9A-Za-z] characters are at codepoints beyond 0x80.
1254  *    Not only do they require all 8 bits instead of 7, if chars are
1255  *    signed, they will have negative integer values! Something like
1256  *    (c - 'A') could actually become (c + 63)! Use the ord() macro to
1257  *    ensure you're getting a value in [0, 255] (ORD for constants).
1258  * 4. '\n' is actually NL (0x15, U+0085) instead of LF (0x25, U+000A).
1259  *    EBCDIC has a proper newline character instead of "emulating" one
1260  *    with line feeds, although this is mapped to LF for our purposes.
1261  * 5. Note that it is possible to compile programs in ASCII mode on IBM
1262  *    mainframe systems, using the -qascii option to the XL C compiler.
1263  *    We can determine the build mode by looking at __CHARSET_LIB:
1264  *    0 == EBCDIC, 1 == ASCII
1265  */
1266 
1267 void
ebcdic_init(void)1268 ebcdic_init(void)
1269 {
1270 	int i = 256;
1271 	unsigned char t;
1272 	bool mapcache[256];
1273 
1274 	while (i--)
1275 		ebcdic_rtt_toascii[i] = i;
1276 	memset(ebcdic_rtt_fromascii, 0xFF, sizeof(ebcdic_rtt_fromascii));
1277 	setlocale(LC_ALL, "");
1278 #ifdef MKSH_EBCDIC
1279 	if (__etoa_l(ebcdic_rtt_toascii, 256) != 256) {
1280 		write(2, "mksh: could not map EBCDIC to ASCII\n", 36);
1281 		exit(255);
1282 	}
1283 #endif
1284 
1285 	memset(mapcache, 0, sizeof(mapcache));
1286 	i = 256;
1287 	while (i--) {
1288 		t = ebcdic_rtt_toascii[i];
1289 		/* ensure unique round-trip capable mapping */
1290 		if (mapcache[t]) {
1291 			write(2, "mksh: duplicate EBCDIC to ASCII mapping\n", 40);
1292 			exit(255);
1293 		}
1294 		/*
1295 		 * since there are 256 input octets, this also ensures
1296 		 * the other mapping direction is completely filled
1297 		 */
1298 		mapcache[t] = true;
1299 		/* fill the complete round-trip map */
1300 		ebcdic_rtt_fromascii[t] = i;
1301 		/*
1302 		 * Only use the converted value if it's in the range
1303 		 * [0x00; 0x7F], which I checked; the "extended ASCII"
1304 		 * characters can be any encoding, not just Latin1,
1305 		 * and the C1 control characters other than NEL are
1306 		 * hopeless, but we map EBCDIC NEL to ASCII LF so we
1307 		 * cannot even use C1 NEL.
1308 		 * If ever we map to UCS, bump the table width to
1309 		 * an unsigned int, and or the raw unconverted EBCDIC
1310 		 * values with 0x01000000 instead.
1311 		 */
1312 		if (t < 0x80U)
1313 			ebcdic_map[i] = (unsigned short)ord(t);
1314 		else
1315 			ebcdic_map[i] = (unsigned short)(0x100U | ord(i));
1316 	}
1317 	if (ebcdic_rtt_toascii[0] || ebcdic_rtt_fromascii[0] || ebcdic_map[0]) {
1318 		write(2, "mksh: NUL not at position 0\n", 28);
1319 		exit(255);
1320 	}
1321 }
1322 #endif
1323