1 /* vi: set sw=4 ts=4: */
2 /*
3 * Utility routines.
4 *
5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6 * Copyright (C) 2006 Rob Landley
7 * Copyright (C) 2006 Denys Vlasenko
8 *
9 * Licensed under GPLv2, see file LICENSE in this source tree.
10 */
11 /* We need to have separate xfuncs.c and xfuncs_printf.c because
12 * with current linkers, even with section garbage collection,
13 * if *.o module references any of XXXprintf functions, you pull in
14 * entire printf machinery. Even if you do not use the function
15 * which uses XXXprintf.
16 *
17 * xfuncs.c contains functions (not necessarily xfuncs)
18 * which do not pull in printf, directly or indirectly.
19 * xfunc_printf.c contains those which do.
20 *
21 * TODO: move xmalloc() and xatonum() here.
22 */
23 #include "libbb.h"
24
25 /* Turn on nonblocking I/O on a fd */
ndelay_on(int fd)26 int FAST_FUNC ndelay_on(int fd)
27 {
28 int flags = fcntl(fd, F_GETFL);
29 if (flags & O_NONBLOCK)
30 return flags;
31 fcntl(fd, F_SETFL, flags | O_NONBLOCK);
32 return flags;
33 }
34
ndelay_off(int fd)35 int FAST_FUNC ndelay_off(int fd)
36 {
37 int flags = fcntl(fd, F_GETFL);
38 if (!(flags & O_NONBLOCK))
39 return flags;
40 fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
41 return flags;
42 }
43
close_on_exec_on(int fd)44 void FAST_FUNC close_on_exec_on(int fd)
45 {
46 fcntl(fd, F_SETFD, FD_CLOEXEC);
47 }
48
strncpy_IFNAMSIZ(char * dst,const char * src)49 char* FAST_FUNC strncpy_IFNAMSIZ(char *dst, const char *src)
50 {
51 #ifndef IFNAMSIZ
52 enum { IFNAMSIZ = 16 };
53 #endif
54 return strncpy(dst, src, IFNAMSIZ);
55 }
56
57
58 /* Convert unsigned integer to ascii, writing into supplied buffer.
59 * A truncated result contains the first few digits of the result ala strncpy.
60 * Returns a pointer past last generated digit, does _not_ store NUL.
61 */
utoa_to_buf(unsigned n,char * buf,unsigned buflen)62 char* FAST_FUNC utoa_to_buf(unsigned n, char *buf, unsigned buflen)
63 {
64 unsigned i, out, res;
65
66 if (buflen) {
67 out = 0;
68
69 BUILD_BUG_ON(sizeof(n) != 4 && sizeof(n) != 8);
70 if (sizeof(n) == 4)
71 // 2^32-1 = 4294967295
72 i = 1000000000;
73 #if UINT_MAX > 0xffffffff /* prevents warning about "const too large" */
74 else
75 if (sizeof(n) == 8)
76 // 2^64-1 = 18446744073709551615
77 i = 10000000000000000000;
78 #endif
79 for (; i; i /= 10) {
80 res = n / i;
81 n = n % i;
82 if (res || out || i == 1) {
83 if (--buflen == 0)
84 break;
85 out++;
86 *buf++ = '0' + res;
87 }
88 }
89 }
90 return buf;
91 }
92
93 /* Convert signed integer to ascii, like utoa_to_buf() */
itoa_to_buf(int n,char * buf,unsigned buflen)94 char* FAST_FUNC itoa_to_buf(int n, char *buf, unsigned buflen)
95 {
96 if (!buflen)
97 return buf;
98 if (n < 0) {
99 n = -n;
100 *buf++ = '-';
101 buflen--;
102 }
103 return utoa_to_buf((unsigned)n, buf, buflen);
104 }
105
106 // The following two functions use a static buffer, so calling either one a
107 // second time will overwrite previous results.
108 //
109 // The largest 32 bit integer is -2 billion plus NUL, or 1+10+1=12 bytes.
110 // It so happens that sizeof(int) * 3 is enough for 32+ bit ints.
111 // (sizeof(int) * 3 + 2 is correct for any width, even 8-bit)
112
113 static char local_buf[sizeof(int) * 3];
114
115 /* Convert unsigned integer to ascii using a static buffer (returned). */
utoa(unsigned n)116 char* FAST_FUNC utoa(unsigned n)
117 {
118 *(utoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
119
120 return local_buf;
121 }
122
123 /* Convert signed integer to ascii using a static buffer (returned). */
itoa(int n)124 char* FAST_FUNC itoa(int n)
125 {
126 *(itoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
127
128 return local_buf;
129 }
130
131 /* Emit a string of hex representation of bytes */
bin2hex(char * p,const char * cp,int count)132 char* FAST_FUNC bin2hex(char *p, const char *cp, int count)
133 {
134 while (count) {
135 unsigned char c = *cp++;
136 /* put lowercase hex digits */
137 *p++ = 0x20 | bb_hexdigits_upcase[c >> 4];
138 *p++ = 0x20 | bb_hexdigits_upcase[c & 0xf];
139 count--;
140 }
141 return p;
142 }
143
144 /* Convert "[x]x[:][x]x[:][x]x[:][x]x" hex string to binary, no more than COUNT bytes */
hex2bin(char * dst,const char * str,int count)145 char* FAST_FUNC hex2bin(char *dst, const char *str, int count)
146 {
147 errno = EINVAL;
148 while (*str && count) {
149 uint8_t val;
150 uint8_t c = *str++;
151 if (isdigit(c))
152 val = c - '0';
153 else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
154 val = (c|0x20) - ('a' - 10);
155 else
156 return NULL;
157 val <<= 4;
158 c = *str;
159 if (isdigit(c))
160 val |= c - '0';
161 else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
162 val |= (c|0x20) - ('a' - 10);
163 else if (c == ':' || c == '\0')
164 val >>= 4;
165 else
166 return NULL;
167
168 *dst++ = val;
169 if (c != '\0')
170 str++;
171 if (*str == ':')
172 str++;
173 count--;
174 }
175 errno = (*str ? ERANGE : 0);
176 return dst;
177 }
178
179 /* Return how long the file at fd is, if there's any way to determine it. */
180 #ifdef UNUSED
fdlength(int fd)181 off_t FAST_FUNC fdlength(int fd)
182 {
183 off_t bottom = 0, top = 0, pos;
184 long size;
185
186 // If the ioctl works for this, return it.
187
188 if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
189
190 // FIXME: explain why lseek(SEEK_END) is not used here!
191
192 // If not, do a binary search for the last location we can read. (Some
193 // block devices don't do BLKGETSIZE right.)
194
195 do {
196 char temp;
197
198 pos = bottom + (top - bottom) / 2;
199
200 // If we can read from the current location, it's bigger.
201
202 if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) {
203 if (bottom == top) bottom = top = (top+1) * 2;
204 else bottom = pos;
205
206 // If we can't, it's smaller.
207 } else {
208 if (bottom == top) {
209 if (!top) return 0;
210 bottom = top/2;
211 }
212 else top = pos;
213 }
214 } while (bottom + 1 != top);
215
216 return pos + 1;
217 }
218 #endif
219
bb_putchar_stderr(char ch)220 int FAST_FUNC bb_putchar_stderr(char ch)
221 {
222 return write(STDERR_FILENO, &ch, 1);
223 }
224
full_write1_str(const char * str)225 ssize_t FAST_FUNC full_write1_str(const char *str)
226 {
227 return full_write(STDOUT_FILENO, str, strlen(str));
228 }
229
full_write2_str(const char * str)230 ssize_t FAST_FUNC full_write2_str(const char *str)
231 {
232 return full_write(STDERR_FILENO, str, strlen(str));
233 }
234
wh_helper(int value,int def_val,const char * env_name,int * err)235 static int wh_helper(int value, int def_val, const char *env_name, int *err)
236 {
237 /* Envvars override even if "value" from ioctl is valid (>0).
238 * Rationale: it's impossible to guess what user wants.
239 * For example: "man CMD | ...": should "man" format output
240 * to stdout's width? stdin's width? /dev/tty's width? 80 chars?
241 * We _cant_ know it. If "..." saves text for e.g. email,
242 * then it's probably 80 chars.
243 * If "..." is, say, "grep -v DISCARD | $PAGER", then user
244 * would prefer his tty's width to be used!
245 *
246 * Since we don't know, at least allow user to do this:
247 * "COLUMNS=80 man CMD | ..."
248 */
249 char *s = getenv(env_name);
250 if (s) {
251 value = atoi(s);
252 /* If LINES/COLUMNS are set, pretend that there is
253 * no error getting w/h, this prevents some ugly
254 * cursor tricks by our callers */
255 *err = 0;
256 }
257
258 if (value <= 1 || value >= 30000)
259 value = def_val;
260 return value;
261 }
262
263 /* It is perfectly ok to pass in a NULL for either width or for
264 * height, in which case that value will not be set. */
get_terminal_width_height(int fd,unsigned * width,unsigned * height)265 int FAST_FUNC get_terminal_width_height(int fd, unsigned *width, unsigned *height)
266 {
267 struct winsize win;
268 int err;
269 int close_me = -1;
270
271 if (fd == -1) {
272 if (isatty(STDOUT_FILENO))
273 fd = STDOUT_FILENO;
274 else
275 if (isatty(STDERR_FILENO))
276 fd = STDERR_FILENO;
277 else
278 if (isatty(STDIN_FILENO))
279 fd = STDIN_FILENO;
280 else
281 close_me = fd = open("/dev/tty", O_RDONLY);
282 }
283
284 win.ws_row = 0;
285 win.ws_col = 0;
286 /* I've seen ioctl returning 0, but row/col is (still?) 0.
287 * We treat that as an error too. */
288 err = ioctl(fd, TIOCGWINSZ, &win) != 0 || win.ws_row == 0;
289 if (height)
290 *height = wh_helper(win.ws_row, 24, "LINES", &err);
291 if (width)
292 *width = wh_helper(win.ws_col, 80, "COLUMNS", &err);
293
294 if (close_me >= 0)
295 close(close_me);
296
297 return err;
298 }
get_terminal_width(int fd)299 int FAST_FUNC get_terminal_width(int fd)
300 {
301 unsigned width;
302 get_terminal_width_height(fd, &width, NULL);
303 return width;
304 }
305
is_TERM_dumb(void)306 int FAST_FUNC is_TERM_dumb(void)
307 {
308 char *term = getenv("TERM");
309 return term && strcmp(term, "dumb") == 0;
310 }
311
tcsetattr_stdin_TCSANOW(const struct termios * tp)312 int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp)
313 {
314 return tcsetattr(STDIN_FILENO, TCSANOW, tp);
315 }
316
get_termios_and_make_raw(int fd,struct termios * newterm,struct termios * oldterm,int flags)317 int FAST_FUNC get_termios_and_make_raw(int fd, struct termios *newterm, struct termios *oldterm, int flags)
318 {
319 //TODO: slattach, shell read might be adapted to use this too: grep for "tcsetattr", "[VTIME] = 0"
320 int r;
321
322 memset(oldterm, 0, sizeof(*oldterm)); /* paranoia */
323 r = tcgetattr(fd, oldterm);
324 *newterm = *oldterm;
325
326 /* Turn off buffered input (ICANON)
327 * Turn off echoing (ECHO)
328 * and separate echoing of newline (ECHONL, normally off anyway)
329 */
330 newterm->c_lflag &= ~(ICANON | ECHO | ECHONL);
331 if (flags & TERMIOS_CLEAR_ISIG) {
332 /* dont recognize INT/QUIT/SUSP chars */
333 newterm->c_lflag &= ~ISIG;
334 }
335 /* reads will block only if < 1 char is available */
336 newterm->c_cc[VMIN] = 1;
337 /* no timeout (reads block forever) */
338 newterm->c_cc[VTIME] = 0;
339 /* IXON, IXOFF, and IXANY:
340 * IXOFF=1: sw flow control is enabled on input queue:
341 * tty transmits a STOP char when input queue is close to full
342 * and transmits a START char when input queue is nearly empty.
343 * IXON=1: sw flow control is enabled on output queue:
344 * tty will stop sending if STOP char is received,
345 * and resume sending if START is received, or if any char
346 * is received and IXANY=1.
347 */
348 if (flags & TERMIOS_RAW_CRNL_INPUT) {
349 /* IXON=0: XON/XOFF chars are treated as normal chars (why we do this?) */
350 /* dont convert CR to NL on input */
351 newterm->c_iflag &= ~(IXON | ICRNL);
352 }
353 if (flags & TERMIOS_RAW_CRNL_OUTPUT) {
354 /* dont convert NL to CR+NL on output */
355 newterm->c_oflag &= ~(ONLCR);
356 /* Maybe clear more c_oflag bits? Usually, only OPOST and ONLCR are set.
357 * OPOST Enable output processing (reqd for OLCUC and *NL* bits to work)
358 * OLCUC Map lowercase characters to uppercase on output.
359 * OCRNL Map CR to NL on output.
360 * ONOCR Don't output CR at column 0.
361 * ONLRET Don't output CR.
362 */
363 }
364 if (flags & TERMIOS_RAW_INPUT) {
365 #ifndef IMAXBEL
366 # define IMAXBEL 0
367 #endif
368 #ifndef IUCLC
369 # define IUCLC 0
370 #endif
371 #ifndef IXANY
372 # define IXANY 0
373 #endif
374 /* IXOFF=0: disable sending XON/XOFF if input buf is full
375 * IXON=0: input XON/XOFF chars are not special
376 * BRKINT=0: dont send SIGINT on break
377 * IMAXBEL=0: dont echo BEL on input line too long
378 * INLCR,ICRNL,IUCLC: dont convert anything on input
379 */
380 newterm->c_iflag &= ~(IXOFF|IXON|IXANY|BRKINT|INLCR|ICRNL|IUCLC|IMAXBEL);
381 }
382 return r;
383 }
384
set_termios_to_raw(int fd,struct termios * oldterm,int flags)385 int FAST_FUNC set_termios_to_raw(int fd, struct termios *oldterm, int flags)
386 {
387 struct termios newterm;
388
389 get_termios_and_make_raw(fd, &newterm, oldterm, flags);
390 return tcsetattr(fd, TCSANOW, &newterm);
391 }
392
safe_waitpid(pid_t pid,int * wstat,int options)393 pid_t FAST_FUNC safe_waitpid(pid_t pid, int *wstat, int options)
394 {
395 pid_t r;
396
397 do
398 r = waitpid(pid, wstat, options);
399 while ((r == -1) && (errno == EINTR));
400 return r;
401 }
402
wait_any_nohang(int * wstat)403 pid_t FAST_FUNC wait_any_nohang(int *wstat)
404 {
405 return safe_waitpid(-1, wstat, WNOHANG);
406 }
407
408 // Wait for the specified child PID to exit, returning child's error return.
wait4pid(pid_t pid)409 int FAST_FUNC wait4pid(pid_t pid)
410 {
411 int status;
412
413 if (pid <= 0) {
414 /*errno = ECHILD; -- wrong. */
415 /* we expect errno to be already set from failed [v]fork/exec */
416 return -1;
417 }
418 if (safe_waitpid(pid, &status, 0) == -1)
419 return -1;
420 if (WIFEXITED(status))
421 return WEXITSTATUS(status);
422 if (WIFSIGNALED(status))
423 return WTERMSIG(status) + 0x180;
424 return 0;
425 }
426