Bug Summary

File:src/usr.bin/csplit/csplit.c
Warning:line 134, column 2
Value stored to 'argc' is never read

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name csplit.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/usr.bin/csplit/obj -resource-dir /usr/local/lib/clang/13.0.0 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/usr.bin/csplit/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c /usr/src/usr.bin/csplit/csplit.c
1/* $OpenBSD: csplit.c,v 1.10 2021/07/08 00:38:42 millert Exp $ */
2/* $FreeBSD: src/usr.bin/csplit/csplit.c,v 1.9 2004/03/22 11:15:03 tjr Exp $ */
3
4/*-
5 * Copyright (c) 2002 Tim J. Robbins.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30/*
31 * csplit -- split files based on context
32 *
33 * This utility splits its input into numbered output files by line number
34 * or by a regular expression. Regular expression matches have an optional
35 * offset with them, allowing the split to occur a specified number of
36 * lines before or after the match.
37 *
38 * To handle negative offsets, we stop reading when the match occurs and
39 * store the offset that the file should have been split at, then use
40 * this output file as input until all the "overflowed" lines have been read.
41 * The file is then closed and truncated to the correct length.
42 *
43 * We assume that the output files can be seeked upon (ie. they cannot be
44 * symlinks to named pipes or character devices), but make no such
45 * assumption about the input.
46 */
47
48#include <sys/types.h>
49
50#include <ctype.h>
51#include <err.h>
52#include <errno(*__errno()).h>
53#include <limits.h>
54#include <regex.h>
55#include <signal.h>
56#include <stdint.h>
57#include <stdio.h>
58#include <stdlib.h>
59#include <string.h>
60#include <unistd.h>
61
62void cleanup(void);
63void do_lineno(const char *);
64void do_rexp(const char *);
65char *get_line(void);
66void handlesig(int);
67FILE *newfile(void);
68void toomuch(FILE *, long);
69static void __dead__attribute__((__noreturn__)) usage(void);
70
71/*
72 * Command line options
73 */
74const char *prefix; /* File name prefix */
75long sufflen; /* Number of decimal digits for suffix */
76int sflag; /* Suppress output of file names */
77int kflag; /* Keep output if error occurs */
78
79/*
80 * Other miscellaneous globals (XXX too many)
81 */
82long lineno; /* Current line number in input file */
83long reps; /* Number of repetitions for this pattern */
84long nfiles; /* Number of files output so far */
85long maxfiles; /* Maximum number of files we can create */
86char currfile[PATH_MAX1024]; /* Current output file */
87const char *infn; /* Name of the input file */
88FILE *infile; /* Input file handle */
89FILE *overfile; /* Overflow file for toomuch() */
90off_t truncofs; /* Offset this file should be truncated at */
91int doclean; /* Should cleanup() remove output? */
92
93int
94main(int argc, char *argv[])
95{
96 struct sigaction sa;
97 long i;
98 int ch;
99 const char *expr;
100 char *ep, *p;
101 FILE *ofp;
102
103 if (pledge("stdio rpath wpath cpath", NULL((void *)0)) == -1)
104 err(1, "pledge");
105
106 kflag = sflag = 0;
107 prefix = "xx";
108 sufflen = 2;
109 while ((ch = getopt(argc, argv, "f:kn:s")) != -1) {
110 switch (ch) {
111 case 'f':
112 prefix = optarg;
113 break;
114 case 'k':
115 kflag = 1;
116 break;
117 case 'n':
118 errno(*__errno()) = 0;
119 sufflen = strtol(optarg, &ep, 10);
120 if (sufflen <= 0 || *ep != '\0' || errno(*__errno()) != 0)
121 errx(1, "%s: bad suffix length", optarg);
122 break;
123 case 's':
124 sflag = 1;
125 break;
126 default:
127 usage();
128 }
129 }
130
131 if (sufflen + strlen(prefix) >= PATH_MAX1024)
132 errx(1, "name too long");
133
134 argc -= optind;
Value stored to 'argc' is never read
135 argv += optind;
136
137 if ((infn = *argv++) == NULL((void *)0))
138 usage();
139 if (strcmp(infn, "-") == 0) {
140 infile = stdin(&__sF[0]);
141 infn = "stdin";
142 } else if ((infile = fopen(infn, "r")) == NULL((void *)0))
143 err(1, "%s", infn);
144
145 if (!kflag) {
146 doclean = 1;
147 atexit(cleanup);
148 sa.sa_flags = 0;
149 sa.sa_handler__sigaction_u.__sa_handler = handlesig;
150 sigemptyset(&sa.sa_mask);
151 sigaddset(&sa.sa_mask, SIGHUP1);
152 sigaddset(&sa.sa_mask, SIGINT2);
153 sigaddset(&sa.sa_mask, SIGTERM15);
154 sigaction(SIGHUP1, &sa, NULL((void *)0));
155 sigaction(SIGINT2, &sa, NULL((void *)0));
156 sigaction(SIGTERM15, &sa, NULL((void *)0));
157 }
158
159 lineno = 0;
160 nfiles = 0;
161 truncofs = 0;
162 overfile = NULL((void *)0);
163
164 /* Ensure 10^sufflen < LONG_MAX. */
165 for (maxfiles = 1, i = 0; i < sufflen; i++) {
166 if (maxfiles > LONG_MAX9223372036854775807L / 10)
167 errx(1, "%ld: suffix too long (limit %ld)",
168 sufflen, i);
169 maxfiles *= 10;
170 }
171
172 /* Create files based on supplied patterns. */
173 while (nfiles < maxfiles - 1 && (expr = *argv++) != NULL((void *)0)) {
174 /* Look ahead & see if this pattern has any repetitions. */
175 if (*argv != NULL((void *)0) && **argv == '{') {
176 errno(*__errno()) = 0;
177 reps = strtol(*argv + 1, &ep, 10);
178 if (reps < 0 || *ep != '}' || errno(*__errno()) != 0)
179 errx(1, "%s: bad repetition count", *argv + 1);
180 argv++;
181 } else
182 reps = 0;
183
184 if (*expr == '/' || *expr == '%') {
185 do {
186 do_rexp(expr);
187 } while (reps-- != 0 && nfiles < maxfiles - 1);
188 } else if (isdigit((unsigned char)*expr))
189 do_lineno(expr);
190 else
191 errx(1, "%s: unrecognised pattern", expr);
192 }
193
194 /* Copy the rest into a new file. */
195 if (!feof(infile)(!__isthreaded ? (((infile)->_flags & 0x0020) != 0) : (
feof)(infile))
) {
196 ofp = newfile();
197 while ((p = get_line()) != NULL((void *)0) && fputs(p, ofp) == 0)
198 ;
199 if (!sflag)
200 printf("%jd\n", (intmax_t)ftello(ofp));
201 if (fclose(ofp) != 0)
202 err(1, "%s", currfile);
203 }
204
205 toomuch(NULL((void *)0), 0);
206 doclean = 0;
207
208 return (0);
209}
210
211static void __dead__attribute__((__noreturn__))
212usage(void)
213{
214 extern char *__progname;
215
216 fprintf(stderr(&__sF[2]),
217 "usage: %s [-ks] [-f prefix] [-n number] file args ...\n",
218 __progname);
219 exit(1);
220}
221
222/* ARGSUSED */
223void
224handlesig(int sig)
225{
226 const char msg[] = "csplit: caught signal, cleaning up\n";
227
228 write(STDERR_FILENO2, msg, sizeof(msg) - 1);
229 cleanup();
230 _exit(2);
231}
232
233/* Create a new output file. */
234FILE *
235newfile(void)
236{
237 FILE *fp;
238
239 if ((size_t)snprintf(currfile, sizeof(currfile), "%s%0*ld", prefix,
240 (int)sufflen, nfiles) >= sizeof(currfile))
241 errc(1, ENAMETOOLONG63, "%s", currfile);
242 if ((fp = fopen(currfile, "w+")) == NULL((void *)0))
243 err(1, "%s", currfile);
244 nfiles++;
245
246 return (fp);
247}
248
249/* Remove partial output, called before exiting. */
250void
251cleanup(void)
252{
253 char fnbuf[PATH_MAX1024];
254 long i;
255
256 if (!doclean)
257 return;
258
259 /*
260 * NOTE: One cannot portably assume to be able to call snprintf() from
261 * inside a signal handler. It is, however, safe to do on OpenBSD.
262 */
263 for (i = 0; i < nfiles; i++) {
264 snprintf(fnbuf, sizeof(fnbuf), "%s%0*ld", prefix,
265 (int)sufflen, i);
266 unlink(fnbuf);
267 }
268}
269
270/* Read a line from the input into a static buffer. */
271char *
272get_line(void)
273{
274 static char lbuf[LINE_MAX2048];
275 FILE *src;
276
277 src = overfile != NULL((void *)0) ? overfile : infile;
278
279again: if (fgets(lbuf, sizeof(lbuf), src) == NULL((void *)0)) {
280 if (src == overfile) {
281 src = infile;
282 goto again;
283 }
284 return (NULL((void *)0));
285 }
286 if (ferror(src)(!__isthreaded ? (((src)->_flags & 0x0040) != 0) : (ferror
)(src))
)
287 err(1, "%s", infn);
288 lineno++;
289
290 return (lbuf);
291}
292
293/* Conceptually rewind the input (as obtained by get_line()) back `n' lines. */
294void
295toomuch(FILE *ofp, long n)
296{
297 char buf[BUFSIZ1024];
298 size_t i, nread;
299
300 if (overfile != NULL((void *)0)) {
301 /*
302 * Truncate the previous file we overflowed into back to
303 * the correct length, close it.
304 */
305 if (fflush(overfile) != 0)
306 err(1, "overflow");
307 if (ftruncate(fileno(overfile)(!__isthreaded ? ((overfile)->_file) : (fileno)(overfile)), truncofs) != 0)
308 err(1, "overflow");
309 if (fclose(overfile) != 0)
310 err(1, "overflow");
311 overfile = NULL((void *)0);
312 }
313
314 if (n == 0)
315 /* Just tidying up */
316 return;
317
318 lineno -= n;
319
320 /*
321 * Wind the overflow file backwards to `n' lines before the
322 * current one.
323 */
324 do {
325 if (ftello(ofp) < (off_t)sizeof(buf))
326 rewind(ofp);
327 else
328 fseeko(ofp, -(off_t)sizeof(buf), SEEK_CUR1);
329 if (ferror(ofp)(!__isthreaded ? (((ofp)->_flags & 0x0040) != 0) : (ferror
)(ofp))
)
330 errx(1, "%s: can't seek", currfile);
331 if ((nread = fread(buf, 1, sizeof(buf), ofp)) == 0)
332 errx(1, "can't read overflowed output");
333 if (fseeko(ofp, -(off_t)nread, SEEK_CUR1) != 0)
334 err(1, "%s", currfile);
335 for (i = 1; i <= nread; i++)
336 if (buf[nread - i] == '\n' && n-- == 0)
337 break;
338 if (ftello(ofp) == 0)
339 break;
340 } while (n > 0);
341 if (fseeko(ofp, (off_t)(nread - i + 1), SEEK_CUR1) != 0)
342 err(1, "%s", currfile);
343
344 /*
345 * get_line() will read from here. Next call will truncate to
346 * truncofs in this file.
347 */
348 overfile = ofp;
349 truncofs = ftello(overfile);
350}
351
352/* Handle splits for /regexp/ and %regexp% patterns. */
353void
354do_rexp(const char *expr)
355{
356 regex_t cre;
357 intmax_t nwritten;
358 long ofs;
359 int first;
360 char *ecopy, *ep, *p, *pofs, *re;
361 FILE *ofp;
362
363 if ((ecopy = strdup(expr)) == NULL((void *)0))
364 err(1, "strdup");
365
366 re = ecopy + 1;
367 if ((pofs = strrchr(ecopy, *expr)) == NULL((void *)0) || pofs[-1] == '\\')
368 errx(1, "%s: missing trailing %c", expr, *expr);
369 *pofs++ = '\0';
370
371 if (*pofs != '\0') {
372 errno(*__errno()) = 0;
373 ofs = strtol(pofs, &ep, 10);
374 if (*ep != '\0' || errno(*__errno()) != 0)
375 errx(1, "%s: bad offset", pofs);
376 } else
377 ofs = 0;
378
379 if (regcomp(&cre, re, REG_BASIC0000|REG_NOSUB0004) != 0)
380 errx(1, "%s: bad regular expression", re);
381
382 if (*expr == '/')
383 /* /regexp/: Save results to a file. */
384 ofp = newfile();
385 else {
386 /* %regexp%: Make a temporary file for overflow. */
387 if ((ofp = tmpfile()) == NULL((void *)0))
388 err(1, "tmpfile");
389 }
390
391 /* Read and output lines until we get a match. */
392 first = 1;
393 while ((p = get_line()) != NULL((void *)0)) {
394 if (fputs(p, ofp) != 0)
395 break;
396 if (!first && regexec(&cre, p, 0, NULL((void *)0), 0) == 0)
397 break;
398 first = 0;
399 }
400
401 if (p == NULL((void *)0)) {
402 toomuch(NULL((void *)0), 0);
403 errx(1, "%s: no match", re);
404 }
405
406 if (ofs <= 0) {
407 /*
408 * Negative (or zero) offset: throw back any lines we should
409 * not have read yet.
410 */
411 if (p != NULL((void *)0)) {
412 toomuch(ofp, -ofs + 1);
413 nwritten = (intmax_t)truncofs;
414 } else
415 nwritten = (intmax_t)ftello(ofp);
416 } else {
417 /*
418 * Positive offset: copy the requested number of lines
419 * after the match.
420 */
421 while (--ofs > 0 && (p = get_line()) != NULL((void *)0))
422 fputs(p, ofp);
423 toomuch(NULL((void *)0), 0);
424 nwritten = (intmax_t)ftello(ofp);
425 if (fclose(ofp) != 0)
426 err(1, "%s", currfile);
427 }
428
429 if (!sflag && *expr == '/')
430 printf("%jd\n", nwritten);
431
432 regfree(&cre);
433 free(ecopy);
434}
435
436/* Handle splits based on line number. */
437void
438do_lineno(const char *expr)
439{
440 long lastline, tgtline;
441 char *ep, *p;
442 FILE *ofp;
443
444 errno(*__errno()) = 0;
445 tgtline = strtol(expr, &ep, 10);
446 if (tgtline <= 0 || errno(*__errno()) != 0 || *ep != '\0')
447 errx(1, "%s: bad line number", expr);
448 lastline = tgtline;
449 if (lastline <= lineno)
450 errx(1, "%s: can't go backwards", expr);
451
452 while (nfiles < maxfiles - 1) {
453 ofp = newfile();
454 while (lineno + 1 != lastline) {
455 if ((p = get_line()) == NULL((void *)0))
456 errx(1, "%ld: out of range", lastline);
457 if (fputs(p, ofp) != 0)
458 break;
459 }
460 if (!sflag)
461 printf("%jd\n", (intmax_t)ftello(ofp));
462 if (fclose(ofp) != 0)
463 err(1, "%s", currfile);
464 if (reps-- == 0)
465 break;
466 lastline += tgtline;
467 }
468}