source: EcnlProtoTool/trunk/prototool/src/libbb/xfuncs.c@ 279

Last change on this file since 279 was 279, checked in by coas-nagasima, 7 years ago

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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
12/* We need to have separate xfuncs.c and xfuncs_printf.c because
13 * with current linkers, even with section garbage collection,
14 * if *.o module references any of XXXprintf functions, you pull in
15 * entire printf machinery. Even if you do not use the function
16 * which uses XXXprintf.
17 *
18 * xfuncs.c contains functions (not necessarily xfuncs)
19 * which do not pull in printf, directly or indirectly.
20 * xfunc_printf.c contains those which do.
21 *
22 * TODO: move xmalloc() and xatonum() here.
23 */
24
25#include "libbb.h"
26
27/* Turn on nonblocking I/O on a fd */
28int FAST_FUNC ndelay_on(int fd)
29{
30 int flags = fcntl(fd, F_GETFL);
31 if (flags & O_NONBLOCK)
32 return flags;
33 fcntl(fd, F_SETFL, flags | O_NONBLOCK);
34 return flags;
35}
36
37int FAST_FUNC ndelay_off(int fd)
38{
39 int flags = fcntl(fd, F_GETFL);
40 if (!(flags & O_NONBLOCK))
41 return flags;
42 fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
43 return flags;
44}
45
46void FAST_FUNC close_on_exec_on(int fd)
47{
48 fcntl(fd, F_SETFD, FD_CLOEXEC);
49}
50
51char* FAST_FUNC strncpy_IFNAMSIZ(char *dst, const char *src)
52{
53#ifndef IFNAMSIZ
54 enum { IFNAMSIZ = 16 };
55#endif
56 return strncpy(dst, src, IFNAMSIZ);
57}
58
59
60/* Convert unsigned integer to ascii, writing into supplied buffer.
61 * A truncated result contains the first few digits of the result ala strncpy.
62 * Returns a pointer past last generated digit, does _not_ store NUL.
63 */
64void BUG_sizeof(void);
65char* FAST_FUNC utoa_to_buf(unsigned n, char *buf, unsigned buflen)
66{
67 unsigned i, out, res;
68
69 if (buflen) {
70 out = 0;
71 if (sizeof(n) == 4)
72 // 2^32-1 = 4294967295
73 i = 1000000000;
74#if UINT_MAX > 4294967295 /* prevents warning about "const too large" */
75 else
76 if (sizeof(n) == 8)
77 // 2^64-1 = 18446744073709551615
78 i = 10000000000000000000;
79#endif
80 else
81 BUG_sizeof();
82 for (; i; i /= 10) {
83 res = n / i;
84 n = n % i;
85 if (res || out || i == 1) {
86 if (--buflen == 0)
87 break;
88 out++;
89 *buf++ = '0' + res;
90 }
91 }
92 }
93 return buf;
94}
95
96/* Convert signed integer to ascii, like utoa_to_buf() */
97char* FAST_FUNC itoa_to_buf(int n, char *buf, unsigned buflen)
98{
99 if (!buflen)
100 return buf;
101 if (n < 0) {
102 n = -n;
103 *buf++ = '-';
104 buflen--;
105 }
106 return utoa_to_buf((unsigned)n, buf, buflen);
107}
108
109// The following two functions use a static buffer, so calling either one a
110// second time will overwrite previous results.
111//
112// The largest 32 bit integer is -2 billion plus NUL, or 1+10+1=12 bytes.
113// It so happens that sizeof(int) * 3 is enough for 32+ bit ints.
114// (sizeof(int) * 3 + 2 is correct for any width, even 8-bit)
115
116static char local_buf[sizeof(int) * 3];
117
118/* Convert unsigned integer to ascii using a static buffer (returned). */
119char* FAST_FUNC bb_utoa(unsigned n)
120{
121 *(utoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
122
123 return local_buf;
124}
125
126/* Convert signed integer to ascii using a static buffer (returned). */
127char* FAST_FUNC bb_itoa(int n)
128{
129 *(itoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
130
131 return local_buf;
132}
133
134/* Emit a string of hex representation of bytes */
135char* FAST_FUNC bin2hex(char *p, const char *cp, int count)
136{
137 while (count) {
138 unsigned char c = *cp++;
139 /* put lowercase hex digits */
140 *p++ = 0x20 | bb_hexdigits_upcase[c >> 4];
141 *p++ = 0x20 | bb_hexdigits_upcase[c & 0xf];
142 count--;
143 }
144 return p;
145}
146
147/* Convert "[x]x[:][x]x[:][x]x[:][x]x" hex string to binary, no more than COUNT bytes */
148char* FAST_FUNC hex2bin(char *dst, const char *str, int count)
149{
150 errno = EINVAL;
151 while (*str && count) {
152 uint8_t val;
153 uint8_t c = *str++;
154 if (isdigit(c))
155 val = c - '0';
156 else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
157 val = (c|0x20) - ('a' - 10);
158 else
159 return NULL;
160 val <<= 4;
161 c = *str;
162 if (isdigit(c))
163 val |= c - '0';
164 else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
165 val |= (c|0x20) - ('a' - 10);
166 else if (c == ':' || c == '\0')
167 val >>= 4;
168 else
169 return NULL;
170
171 *dst++ = val;
172 if (c != '\0')
173 str++;
174 if (*str == ':')
175 str++;
176 count--;
177 }
178 errno = (*str ? ERANGE : 0);
179 return dst;
180}
181
182/* Return how long the file at fd is, if there's any way to determine it. */
183#ifdef UNUSED
184off_t FAST_FUNC fdlength(int fd)
185{
186 off_t bottom = 0, top = 0, pos;
187 long size;
188
189 // If the ioctl works for this, return it.
190
191 if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
192
193 // FIXME: explain why lseek(SEEK_END) is not used here!
194
195 // If not, do a binary search for the last location we can read. (Some
196 // block devices don't do BLKGETSIZE right.)
197
198 do {
199 char temp;
200
201 pos = bottom + (top - bottom) / 2;
202
203 // If we can read from the current location, it's bigger.
204
205 if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) {
206 if (bottom == top) bottom = top = (top+1) * 2;
207 else bottom = pos;
208
209 // If we can't, it's smaller.
210 } else {
211 if (bottom == top) {
212 if (!top) return 0;
213 bottom = top/2;
214 }
215 else top = pos;
216 }
217 } while (bottom + 1 != top);
218
219 return pos + 1;
220}
221#endif
222
223int FAST_FUNC bb_putchar_stderr(char ch)
224{
225 return write(STDERR_FILENO, &ch, 1);
226}
227
228ssize_t FAST_FUNC full_write1_str(const char *str)
229{
230 return full_write(STDOUT_FILENO, str, strlen(str));
231}
232
233ssize_t FAST_FUNC full_write2_str(const char *str)
234{
235 return full_write(STDERR_FILENO, str, strlen(str));
236}
237
238static int wh_helper(int value, int def_val, const char *env_name, int *err)
239{
240 /* Envvars override even if "value" from ioctl is valid (>0).
241 * Rationale: it's impossible to guess what user wants.
242 * For example: "man CMD | ...": should "man" format output
243 * to stdout's width? stdin's width? /dev/tty's width? 80 chars?
244 * We _cant_ know it. If "..." saves text for e.g. email,
245 * then it's probably 80 chars.
246 * If "..." is, say, "grep -v DISCARD | $PAGER", then user
247 * would prefer his tty's width to be used!
248 *
249 * Since we don't know, at least allow user to do this:
250 * "COLUMNS=80 man CMD | ..."
251 */
252 char *s = getenv(env_name);
253 if (s) {
254 value = atoi(s);
255 /* If LINES/COLUMNS are set, pretend that there is
256 * no error getting w/h, this prevents some ugly
257 * cursor tricks by our callers */
258 *err = 0;
259 }
260
261 if (value <= 1 || value >= 30000)
262 value = def_val;
263 return value;
264}
265
266/* It is perfectly ok to pass in a NULL for either width or for
267 * height, in which case that value will not be set. */
268int FAST_FUNC get_terminal_width_height(int fd, unsigned *width, unsigned *height)
269{
270 struct winsize win;
271 int err;
272 int close_me = -1;
273
274 if (fd == -1) {
275 if (isatty(STDOUT_FILENO))
276 fd = STDOUT_FILENO;
277 else
278 if (isatty(STDERR_FILENO))
279 fd = STDERR_FILENO;
280 else
281 if (isatty(STDIN_FILENO))
282 fd = STDIN_FILENO;
283 else
284 close_me = fd = open("/dev/tty", O_RDONLY);
285 }
286
287 win.ws_row = 0;
288 win.ws_col = 0;
289 /* I've seen ioctl returning 0, but row/col is (still?) 0.
290 * We treat that as an error too. */
291 err = ioctl(fd, TIOCGWINSZ, &win) != 0 || win.ws_row == 0;
292 if (height)
293 *height = wh_helper(win.ws_row, 24, "LINES", &err);
294 if (width)
295 *width = wh_helper(win.ws_col, 80, "COLUMNS", &err);
296
297 if (close_me >= 0)
298 close(close_me);
299
300 return err;
301}
302int FAST_FUNC get_terminal_width(int fd)
303{
304 unsigned width;
305 get_terminal_width_height(fd, &width, NULL);
306 return width;
307}
308
309int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp)
310{
311 return tcsetattr(STDIN_FILENO, TCSANOW, tp);
312}
313
314pid_t FAST_FUNC safe_waitpid(pid_t pid, int *wstat, int options)
315{
316 pid_t r;
317
318 do
319 r = waitpid(pid, wstat, options);
320 while ((r == -1) && (errno == EINTR));
321 return r;
322}
323
324pid_t FAST_FUNC wait_any_nohang(int *wstat)
325{
326 return safe_waitpid(-1, wstat, WNOHANG);
327}
328
329// Wait for the specified child PID to exit, returning child's error return.
330int FAST_FUNC wait4pid(pid_t pid)
331{
332 int status;
333
334 if (pid <= 0) {
335 /*errno = ECHILD; -- wrong. */
336 /* we expect errno to be already set from failed [v]fork/exec */
337 return -1;
338 }
339 if (safe_waitpid(pid, &status, 0) == -1)
340 return -1;
341 if (WIFEXITED(status))
342 return WEXITSTATUS(status);
343 if (WIFSIGNALED(status))
344 return WTERMSIG(status) + 0x180;
345 return 0;
346}
347
348// Useful when we do know that pid is valid, and we just want to wait
349// for it to exit. Not existing pid is fatal. waitpid() status is not returned.
350int FAST_FUNC wait_for_exitstatus(pid_t pid)
351{
352 int exit_status, n;
353
354 n = safe_waitpid(pid, &exit_status, 0);
355 if (n < 0)
356 bb_perror_msg_and_die("waitpid");
357 return exit_status;
358}
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