busybox/libbb/xfuncs.c

/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 * Copyright (C) 2006 Rob Landley
 * Copyright (C) 2006 Denys Vlasenko
 *
 * Licensed under GPL version 2, see file LICENSE in this tarball for details.
 */

/* We need to have separate xfuncs.c and xfuncs_printf.c because
 * with current linkers, even with section garbage collection,
 * if *.o module references any of XXXprintf functions, you pull in
 * entire printf machinery. Even if you do not use the function
 * which uses XXXprintf.
 *
 * xfuncs.c contains functions (not necessarily xfuncs)
 * which do not pull in printf, directly or indirectly.
 * xfunc_printf.c contains those which do.
 *
 * TODO: move xmalloc() and xatonum() here.
 */

#include "libbb.h"

/* Turn on nonblocking I/O on a fd */
int FAST_FUNC ndelay_on(int fd)
{
	return fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
}

int FAST_FUNC ndelay_off(int fd)
{
	return fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK);
}

int FAST_FUNC close_on_exec_on(int fd)
{
	return fcntl(fd, F_SETFD, FD_CLOEXEC);
}

char* FAST_FUNC strncpy_IFNAMSIZ(char *dst, const char *src)
{
#ifndef IFNAMSIZ
	enum { IFNAMSIZ = 16 };
#endif
	return strncpy(dst, src, IFNAMSIZ);
}


/* Convert unsigned integer to ascii, writing into supplied buffer.
 * A truncated result contains the first few digits of the result ala strncpy.
 * Returns a pointer past last generated digit, does _not_ store NUL.
 */
void BUG_sizeof(void);
char* FAST_FUNC utoa_to_buf(unsigned n, char *buf, unsigned buflen)
{
	unsigned i, out, res;

	if (buflen) {
		out = 0;
		if (sizeof(n) == 4)
		// 2^32-1 = 4294967295
			i = 1000000000;
#if UINT_MAX > 4294967295 /* prevents warning about "const too large" */
		else
		if (sizeof(n) == 8)
		// 2^64-1 = 18446744073709551615
			i = 10000000000000000000;
#endif
		else
			BUG_sizeof();
		for (; i; i /= 10) {
			res = n / i;
			n = n % i;
			if (res || out || i == 1) {
				if (--buflen == 0)
					break;
				out++;
				*buf++ = '0' + res;
			}
		}
	}
	return buf;
}

/* Convert signed integer to ascii, like utoa_to_buf() */
char* FAST_FUNC itoa_to_buf(int n, char *buf, unsigned buflen)
{
	if (!buflen)
		return buf;
	if (n < 0) {
		n = -n;
		*buf++ = '-';
		buflen--;
	}
	return utoa_to_buf((unsigned)n, buf, buflen);
}

// The following two functions use a static buffer, so calling either one a
// second time will overwrite previous results.
//
// The largest 32 bit integer is -2 billion plus NUL, or 1+10+1=12 bytes.
// It so happens that sizeof(int) * 3 is enough for 32+ bit ints.
// (sizeof(int) * 3 + 2 is correct for any width, even 8-bit)

static char local_buf[sizeof(int) * 3];

/* Convert unsigned integer to ascii using a static buffer (returned). */
char* FAST_FUNC utoa(unsigned n)
{
	*(utoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';

	return local_buf;
}

/* Convert signed integer to ascii using a static buffer (returned). */
char* FAST_FUNC itoa(int n)
{
	*(itoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';

	return local_buf;
}

/* Emit a string of hex representation of bytes */
char* FAST_FUNC bin2hex(char *p, const char *cp, int count)
{
	while (count) {
		unsigned char c = *cp++;
		/* put lowercase hex digits */
		*p++ = 0x20 | bb_hexdigits_upcase[c >> 4];
		*p++ = 0x20 | bb_hexdigits_upcase[c & 0xf];
		count--;
	}
	return p;
}

/* Convert "[x]x[:][x]x[:][x]x[:][x]x" hex string to binary, no more than COUNT bytes */
char* FAST_FUNC hex2bin(char *dst, const char *str, int count)
{
	errno = EINVAL;
	while (*str && count) {
		uint8_t val;
		uint8_t c = *str++;
		if (isdigit(c))
			val = c - '0';
		else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
			val = (c|0x20) - ('a' - 10);
		else
			return NULL;
		val <<= 4;
		c = *str;
		if (isdigit(c))
			val |= c - '0';
		else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
			val |= (c|0x20) - ('a' - 10);
		else if (c == ':' || c == '\0')
			val >>= 4;
		else
			return NULL;

		*dst++ = val;
		if (c != '\0')
			str++;
		if (*str == ':')
			str++;
		count--;
	}
	errno = (*str ? ERANGE : 0);
	return dst;
}

/* Return how long the file at fd is, if there's any way to determine it. */
#ifdef UNUSED
off_t FAST_FUNC fdlength(int fd)
{
	off_t bottom = 0, top = 0, pos;
	long size;

	// If the ioctl works for this, return it.

	if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;

	// FIXME: explain why lseek(SEEK_END) is not used here!

	// If not, do a binary search for the last location we can read.  (Some
	// block devices don't do BLKGETSIZE right.)

	do {
		char temp;

		pos = bottom + (top - bottom) / 2;

		// If we can read from the current location, it's bigger.

		if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) {
			if (bottom == top) bottom = top = (top+1) * 2;
			else bottom = pos;

		// If we can't, it's smaller.

		} else {
			if (bottom == top) {
				if (!top) return 0;
				bottom = top/2;
			}
			else top = pos;
		}
	} while (bottom + 1 != top);

	return pos + 1;
}
#endif

int FAST_FUNC bb_putchar_stderr(char ch)
{
	return write(STDERR_FILENO, &ch, 1);
}

ssize_t FAST_FUNC full_write1_str(const char *str)
{
	return full_write(STDOUT_FILENO, str, strlen(str));
}

ssize_t FAST_FUNC full_write2_str(const char *str)
{
	return full_write(STDERR_FILENO, str, strlen(str));
}

static int wh_helper(int value, int def_val, const char *env_name, int *err)
{
	if (value == 0) {
		char *s = getenv(env_name);
		if (s) {
			value = atoi(s);
			/* If LINES/COLUMNS are set, pretent that there is
			 * no error getting w/h, this prevents some ugly
			 * cursor tricks by our callers */
			*err = 0;
		}
	}
	if (value <= 1 || value >= 30000)
		value = def_val;
	return value;
}

/* It is perfectly ok to pass in a NULL for either width or for
 * height, in which case that value will not be set.  */
int FAST_FUNC get_terminal_width_height(int fd, unsigned *width, unsigned *height)
{
	struct winsize win;
	int err;

	win.ws_row = 0;
	win.ws_col = 0;
	/* I've seen ioctl returning 0, but row/col is (still?) 0.
	 * We treat that as an error too.  */
	err = ioctl(fd, TIOCGWINSZ, &win) != 0 || win.ws_row == 0;
	if (height)
		*height = wh_helper(win.ws_row, 24, "LINES", &err);
	if (width)
		*width = wh_helper(win.ws_col, 80, "COLUMNS", &err);
	return err;
}

int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp)
{
	return tcsetattr(STDIN_FILENO, TCSANOW, tp);
}

pid_t FAST_FUNC safe_waitpid(pid_t pid, int *wstat, int options)
{
	pid_t r;

	do
		r = waitpid(pid, wstat, options);
	while ((r == -1) && (errno == EINTR));
	return r;
}

pid_t FAST_FUNC wait_any_nohang(int *wstat)
{
	return safe_waitpid(-1, wstat, WNOHANG);
}

// Wait for the specified child PID to exit, returning child's error return.
int FAST_FUNC wait4pid(pid_t pid)
{
	int status;

	if (pid <= 0) {
		/*errno = ECHILD; -- wrong. */
		/* we expect errno to be already set from failed [v]fork/exec */
		return -1;
	}
	if (safe_waitpid(pid, &status, 0) == -1)
		return -1;
	if (WIFEXITED(status))
		return WEXITSTATUS(status);
	if (WIFSIGNALED(status))
		return WTERMSIG(status) + 0x180;
	return 0;
}
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 GPL version 2, see file LICENSE in this tarball for details.
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 */
28	int FAST_FUNC ndelay_on(int fd)
29	{
30	return fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) \| O_NONBLOCK);
31	}
32
33	int FAST_FUNC ndelay_off(int fd)
34	{
35	return fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) & ~O_NONBLOCK);
36	}
37
38	int FAST_FUNC close_on_exec_on(int fd)
39	{
40	return fcntl(fd, F_SETFD, FD_CLOEXEC);
41	}
42
43	char* FAST_FUNC strncpy_IFNAMSIZ(char dst, const char src)
44	{
45	#ifndef IFNAMSIZ
46	enum { IFNAMSIZ = 16 };
47	#endif
48	return strncpy(dst, src, IFNAMSIZ);
49	}
50
51
52	/* Convert unsigned integer to ascii, writing into supplied buffer.
53	* A truncated result contains the first few digits of the result ala strncpy.
54	* Returns a pointer past last generated digit, does _not_ store NUL.
55	*/
56	void BUG_sizeof(void);
57	char* FAST_FUNC utoa_to_buf(unsigned n, char *buf, unsigned buflen)
58	{
59	unsigned i, out, res;
60
61	if (buflen) {
62	out = 0;
63	if (sizeof(n) == 4)
64	// 2^32-1 = 4294967295
65	i = 1000000000;
66	#if UINT_MAX > 4294967295 /* prevents warning about "const too large" */
67	else
68	if (sizeof(n) == 8)
69	// 2^64-1 = 18446744073709551615
70	i = 10000000000000000000;
71	#endif
72	else
73	BUG_sizeof();
74	for (; i; i /= 10) {
75	res = n / i;
76	n = n % i;
77	if (res \|\| out \|\| i == 1) {
78	if (--buflen == 0)
79	break;
80	out++;
81	*buf++ = '0' + res;
82	}
83	}
84	}
85	return buf;
86	}
87
88	/* Convert signed integer to ascii, like utoa_to_buf() */
89	char* FAST_FUNC itoa_to_buf(int n, char *buf, unsigned buflen)
90	{
91	if (!buflen)
92	return buf;
93	if (n < 0) {
94	n = -n;
95	*buf++ = '-';
96	buflen--;
97	}
98	return utoa_to_buf((unsigned)n, buf, buflen);
99	}
100
101	// The following two functions use a static buffer, so calling either one a
102	// second time will overwrite previous results.
103	//
104	// The largest 32 bit integer is -2 billion plus NUL, or 1+10+1=12 bytes.
105	// It so happens that sizeof(int) * 3 is enough for 32+ bit ints.
106	// (sizeof(int) * 3 + 2 is correct for any width, even 8-bit)
107
108	static char local_buf[sizeof(int) * 3];
109
110	/* Convert unsigned integer to ascii using a static buffer (returned). */
111	char* FAST_FUNC utoa(unsigned n)
112	{
113	*(utoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
114
115	return local_buf;
116	}
117
118	/* Convert signed integer to ascii using a static buffer (returned). */
119	char* FAST_FUNC itoa(int n)
120	{
121	*(itoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
122
123	return local_buf;
124	}
125
126	/* Emit a string of hex representation of bytes */
127	char* FAST_FUNC bin2hex(char p, const char cp, int count)
128	{
129	while (count) {
130	unsigned char c = *cp++;
131	/* put lowercase hex digits */
132	*p++ = 0x20 \| bb_hexdigits_upcase[c >> 4];
133	*p++ = 0x20 \| bb_hexdigits_upcase[c & 0xf];
134	count--;
135	}
136	return p;
137	}
138
139	/* Convert "[x]x[:][x]x[:][x]x[:][x]x" hex string to binary, no more than COUNT bytes */
140	char* FAST_FUNC hex2bin(char dst, const char str, int count)
141	{
142	errno = EINVAL;
143	while (*str && count) {
144	uint8_t val;
145	uint8_t c = *str++;
146	if (isdigit(c))
147	val = c - '0';
148	else if ((c\|0x20) >= 'a' && (c\|0x20) <= 'f')
149	val = (c\|0x20) - ('a' - 10);
150	else
151	return NULL;
152	val <<= 4;
153	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 if (c == ':' \|\| c == '\0')
159	val >>= 4;
160	else
161	return NULL;
162
163	*dst++ = val;
164	if (c != '\0')
165	str++;
166	if (*str == ':')
167	str++;
168	count--;
169	}
170	errno = (*str ? ERANGE : 0);
171	return dst;
172	}
173
174	/* Return how long the file at fd is, if there's any way to determine it. */
175	#ifdef UNUSED
176	off_t FAST_FUNC fdlength(int fd)
177	{
178	off_t bottom = 0, top = 0, pos;
179	long size;
180
181	// If the ioctl works for this, return it.
182
183	if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
184
185	// FIXME: explain why lseek(SEEK_END) is not used here!
186
187	// If not, do a binary search for the last location we can read. (Some
188	// block devices don't do BLKGETSIZE right.)
189
190	do {
191	char temp;
192
193	pos = bottom + (top - bottom) / 2;
194
195	// If we can read from the current location, it's bigger.
196
197	if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) {
198	if (bottom == top) bottom = top = (top+1) * 2;
199	else bottom = pos;
200
201	// If we can't, it's smaller.
202
203	} else {
204	if (bottom == top) {
205	if (!top) return 0;
206	bottom = top/2;
207	}
208	else top = pos;
209	}
210	} while (bottom + 1 != top);
211
212	return pos + 1;
213	}
214	#endif
215
216	int FAST_FUNC bb_putchar_stderr(char ch)
217	{
218	return write(STDERR_FILENO, &ch, 1);
219	}
220
221	ssize_t FAST_FUNC full_write1_str(const char *str)
222	{
223	return full_write(STDOUT_FILENO, str, strlen(str));
224	}
225
226	ssize_t FAST_FUNC full_write2_str(const char *str)
227	{
228	return full_write(STDERR_FILENO, str, strlen(str));
229	}
230
231	static int wh_helper(int value, int def_val, const char env_name, int err)
232	{
233	if (value == 0) {
234	char *s = getenv(env_name);
235	if (s) {
236	value = atoi(s);
237	/* If LINES/COLUMNS are set, pretent that there is
238	* no error getting w/h, this prevents some ugly
239	* cursor tricks by our callers */
240	*err = 0;
241	}
242	}
243	if (value <= 1 \|\| value >= 30000)
244	value = def_val;
245	return value;
246	}
247
248	/* It is perfectly ok to pass in a NULL for either width or for
249	* height, in which case that value will not be set. */
250	int FAST_FUNC get_terminal_width_height(int fd, unsigned width, unsigned height)
251	{
252	struct winsize win;
253	int err;
254
255	win.ws_row = 0;
256	win.ws_col = 0;
257	/* I've seen ioctl returning 0, but row/col is (still?) 0.
258	* We treat that as an error too. */
259	err = ioctl(fd, TIOCGWINSZ, &win) != 0 \|\| win.ws_row == 0;
260	if (height)
261	*height = wh_helper(win.ws_row, 24, "LINES", &err);
262	if (width)
263	*width = wh_helper(win.ws_col, 80, "COLUMNS", &err);
264	return err;
265	}
266
267	int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp)
268	{
269	return tcsetattr(STDIN_FILENO, TCSANOW, tp);
270	}
271
272	pid_t FAST_FUNC safe_waitpid(pid_t pid, int *wstat, int options)
273	{
274	pid_t r;
275
276	do
277	r = waitpid(pid, wstat, options);
278	while ((r == -1) && (errno == EINTR));
279	return r;
280	}
281
282	pid_t FAST_FUNC wait_any_nohang(int *wstat)
283	{
284	return safe_waitpid(-1, wstat, WNOHANG);
285	}
286
287	// Wait for the specified child PID to exit, returning child's error return.
288	int FAST_FUNC wait4pid(pid_t pid)
289	{
290	int status;
291
292	if (pid <= 0) {
293	/errno = ECHILD; -- wrong. /
294	/* we expect errno to be already set from failed [v]fork/exec */
295	return -1;
296	}
297	if (safe_waitpid(pid, &status, 0) == -1)
298	return -1;
299	if (WIFEXITED(status))
300	return WEXITSTATUS(status);
301	if (WIFSIGNALED(status))
302	return WTERMSIG(status) + 0x180;
303	return 0;
304	}