source: branches/3.2/mindi-busybox/libbb/xfuncs.c

Last change on this file was 3232, checked in by bruno, 5 years ago
  • Update mindi-busybox to 1.21.1
File size: 7.0 KB
Line 
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 */
28void FAST_FUNC ndelay_on(int fd)
29{
30    int flags = fcntl(fd, F_GETFL);
31    if (flags & O_NONBLOCK)
32        return;
33    fcntl(fd, F_SETFL, flags | O_NONBLOCK);
34}
35
36void FAST_FUNC ndelay_off(int fd)
37{
38    int flags = fcntl(fd, F_GETFL);
39    if (!(flags & O_NONBLOCK))
40        return;
41    fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
42}
43
44void FAST_FUNC close_on_exec_on(int fd)
45{
46    fcntl(fd, F_SETFD, FD_CLOEXEC);
47}
48
49char* 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 */
62void BUG_sizeof(void);
63char* FAST_FUNC utoa_to_buf(unsigned n, char *buf, unsigned buflen)
64{
65    unsigned i, out, res;
66
67    if (buflen) {
68        out = 0;
69        if (sizeof(n) == 4)
70        // 2^32-1 = 4294967295
71            i = 1000000000;
72#if UINT_MAX > 4294967295 /* prevents warning about "const too large" */
73        else
74        if (sizeof(n) == 8)
75        // 2^64-1 = 18446744073709551615
76            i = 10000000000000000000;
77#endif
78        else
79            BUG_sizeof();
80        for (; i; i /= 10) {
81            res = n / i;
82            n = n % i;
83            if (res || out || i == 1) {
84                if (--buflen == 0)
85                    break;
86                out++;
87                *buf++ = '0' + res;
88            }
89        }
90    }
91    return buf;
92}
93
94/* Convert signed integer to ascii, like utoa_to_buf() */
95char* FAST_FUNC itoa_to_buf(int n, char *buf, unsigned buflen)
96{
97    if (!buflen)
98        return buf;
99    if (n < 0) {
100        n = -n;
101        *buf++ = '-';
102        buflen--;
103    }
104    return utoa_to_buf((unsigned)n, buf, buflen);
105}
106
107// The following two functions use a static buffer, so calling either one a
108// second time will overwrite previous results.
109//
110// The largest 32 bit integer is -2 billion plus NUL, or 1+10+1=12 bytes.
111// It so happens that sizeof(int) * 3 is enough for 32+ bit ints.
112// (sizeof(int) * 3 + 2 is correct for any width, even 8-bit)
113
114static char local_buf[sizeof(int) * 3];
115
116/* Convert unsigned integer to ascii using a static buffer (returned). */
117char* FAST_FUNC utoa(unsigned n)
118{
119    *(utoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
120
121    return local_buf;
122}
123
124/* Convert signed integer to ascii using a static buffer (returned). */
125char* FAST_FUNC itoa(int n)
126{
127    *(itoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
128
129    return local_buf;
130}
131
132/* Emit a string of hex representation of bytes */
133char* FAST_FUNC bin2hex(char *p, const char *cp, int count)
134{
135    while (count) {
136        unsigned char c = *cp++;
137        /* put lowercase hex digits */
138        *p++ = 0x20 | bb_hexdigits_upcase[c >> 4];
139        *p++ = 0x20 | bb_hexdigits_upcase[c & 0xf];
140        count--;
141    }
142    return p;
143}
144
145/* Convert "[x]x[:][x]x[:][x]x[:][x]x" hex string to binary, no more than COUNT bytes */
146char* FAST_FUNC hex2bin(char *dst, const char *str, int count)
147{
148    errno = EINVAL;
149    while (*str && count) {
150        uint8_t val;
151        uint8_t c = *str++;
152        if (isdigit(c))
153            val = c - '0';
154        else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
155            val = (c|0x20) - ('a' - 10);
156        else
157            return NULL;
158        val <<= 4;
159        c = *str;
160        if (isdigit(c))
161            val |= c - '0';
162        else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
163            val |= (c|0x20) - ('a' - 10);
164        else if (c == ':' || c == '\0')
165            val >>= 4;
166        else
167            return NULL;
168
169        *dst++ = val;
170        if (c != '\0')
171            str++;
172        if (*str == ':')
173            str++;
174        count--;
175    }
176    errno = (*str ? ERANGE : 0);
177    return dst;
178}
179
180/* Return how long the file at fd is, if there's any way to determine it. */
181#ifdef UNUSED
182off_t FAST_FUNC fdlength(int fd)
183{
184    off_t bottom = 0, top = 0, pos;
185    long size;
186
187    // If the ioctl works for this, return it.
188
189    if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
190
191    // FIXME: explain why lseek(SEEK_END) is not used here!
192
193    // If not, do a binary search for the last location we can read.  (Some
194    // block devices don't do BLKGETSIZE right.)
195
196    do {
197        char temp;
198
199        pos = bottom + (top - bottom) / 2;
200
201        // If we can read from the current location, it's bigger.
202
203        if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) {
204            if (bottom == top) bottom = top = (top+1) * 2;
205            else bottom = pos;
206
207        // If we can't, it's smaller.
208
209        } else {
210            if (bottom == top) {
211                if (!top) return 0;
212                bottom = top/2;
213            }
214            else top = pos;
215        }
216    } while (bottom + 1 != top);
217
218    return pos + 1;
219}
220#endif
221
222int FAST_FUNC bb_putchar_stderr(char ch)
223{
224    return write(STDERR_FILENO, &ch, 1);
225}
226
227ssize_t FAST_FUNC full_write1_str(const char *str)
228{
229    return full_write(STDOUT_FILENO, str, strlen(str));
230}
231
232ssize_t FAST_FUNC full_write2_str(const char *str)
233{
234    return full_write(STDERR_FILENO, str, strlen(str));
235}
236
237static int wh_helper(int value, int def_val, const char *env_name, int *err)
238{
239    if (value == 0) {
240        char *s = getenv(env_name);
241        if (s) {
242            value = atoi(s);
243            /* If LINES/COLUMNS are set, pretend that there is
244             * no error getting w/h, this prevents some ugly
245             * cursor tricks by our callers */
246            *err = 0;
247        }
248    }
249    if (value <= 1 || value >= 30000)
250        value = def_val;
251    return value;
252}
253
254/* It is perfectly ok to pass in a NULL for either width or for
255 * height, in which case that value will not be set.  */
256int FAST_FUNC get_terminal_width_height(int fd, unsigned *width, unsigned *height)
257{
258    struct winsize win;
259    int err;
260
261    win.ws_row = 0;
262    win.ws_col = 0;
263    /* I've seen ioctl returning 0, but row/col is (still?) 0.
264     * We treat that as an error too.  */
265    err = ioctl(fd, TIOCGWINSZ, &win) != 0 || win.ws_row == 0;
266    if (height)
267        *height = wh_helper(win.ws_row, 24, "LINES", &err);
268    if (width)
269        *width = wh_helper(win.ws_col, 80, "COLUMNS", &err);
270    return err;
271}
272
273int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp)
274{
275    return tcsetattr(STDIN_FILENO, TCSANOW, tp);
276}
277
278pid_t FAST_FUNC safe_waitpid(pid_t pid, int *wstat, int options)
279{
280    pid_t r;
281
282    do
283        r = waitpid(pid, wstat, options);
284    while ((r == -1) && (errno == EINTR));
285    return r;
286}
287
288pid_t FAST_FUNC wait_any_nohang(int *wstat)
289{
290    return safe_waitpid(-1, wstat, WNOHANG);
291}
292
293// Wait for the specified child PID to exit, returning child's error return.
294int FAST_FUNC wait4pid(pid_t pid)
295{
296    int status;
297
298    if (pid <= 0) {
299        /*errno = ECHILD; -- wrong. */
300        /* we expect errno to be already set from failed [v]fork/exec */
301        return -1;
302    }
303    if (safe_waitpid(pid, &status, 0) == -1)
304        return -1;
305    if (WIFEXITED(status))
306        return WEXITSTATUS(status);
307    if (WIFSIGNALED(status))
308        return WTERMSIG(status) + 0x180;
309    return 0;
310}
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