libbb/xfuncs.c - busybox - Git at Google

 /* 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);
 }

 /* Convert unsigned long long value into compact 4-char
  * representation. Examples: "1234", "1.2k", " 27M", "123T"
  * String is not terminated (buf[4] is untouched) */
 void FAST_FUNC smart_ulltoa4(unsigned long long ul, char buf[5], const char *scale)
 {
 	const char *fmt;
 	char c;
 	unsigned v, u, idx = 0;

 	if (ul > 9999) { // do not scale if 9999 or less
 		ul *= 10;
 		do {
 			ul /= 1024;
 			idx++;
 		} while (ul >= 10000);
 	}
 	v = ul; // ullong divisions are expensive, avoid them

 	fmt = " 123456789";
 	u = v / 10;
 	v = v % 10;
 	if (!idx) {
 		// 9999 or less: use "1234" format
 		// u is value/10, v is last digit
 		c = buf[0] = " 123456789"[u/100];
 		if (c != ' ') fmt = "0123456789";
 		c = buf[1] = fmt[u/10%10];
 		if (c != ' ') fmt = "0123456789";
 		buf[2] = fmt[u%10];
 		buf[3] = "0123456789"[v];
 	} else {
 		// u is value, v is 1/10ths (allows for 9.2M format)
 		if (u >= 10) {
 			// value is >= 10: use "123M', " 12M" formats
 			c = buf[0] = " 123456789"[u/100];
 			if (c != ' ') fmt = "0123456789";
 			v = u % 10;
 			u = u / 10;
 			buf[1] = fmt[u%10];
 		} else {
 			// value is < 10: use "9.2M" format
 			buf[0] = "0123456789"[u];
 			buf[1] = '.';
 		}
 		buf[2] = "0123456789"[v];
 		buf[3] = scale[idx]; /* typically scale = " kmgt..." */
 	}
 }

 /* Convert unsigned long long value into compact 5-char representation.
  * String is not terminated (buf[5] is untouched) */
 void FAST_FUNC smart_ulltoa5(unsigned long long ul, char buf[6], const char *scale)
 {
 	const char *fmt;
 	char c;
 	unsigned v, u, idx = 0;

 	if (ul > 99999) { // do not scale if 99999 or less
 		ul *= 10;
 		do {
 			ul /= 1024;
 			idx++;
 		} while (ul >= 100000);
 	}
 	v = ul; // ullong divisions are expensive, avoid them

 	fmt = " 123456789";
 	u = v / 10;
 	v = v % 10;
 	if (!idx) {
 		// 99999 or less: use "12345" format
 		// u is value/10, v is last digit
 		c = buf[0] = " 123456789"[u/1000];
 		if (c != ' ') fmt = "0123456789";
 		c = buf[1] = fmt[u/100%10];
 		if (c != ' ') fmt = "0123456789";
 		c = buf[2] = fmt[u/10%10];
 		if (c != ' ') fmt = "0123456789";
 		buf[3] = fmt[u%10];
 		buf[4] = "0123456789"[v];
 	} else {
 		// value has been scaled into 0..9999.9 range
 		// u is value, v is 1/10ths (allows for 92.1M format)
 		if (u >= 100) {
 			// value is >= 100: use "1234M', " 123M" formats
 			c = buf[0] = " 123456789"[u/1000];
 			if (c != ' ') fmt = "0123456789";
 			c = buf[1] = fmt[u/100%10];
 			if (c != ' ') fmt = "0123456789";
 			v = u % 10;
 			u = u / 10;
 			buf[2] = fmt[u%10];
 		} else {
 			// value is < 100: use "92.1M" format
 			c = buf[0] = " 123456789"[u/10];
 			if (c != ' ') fmt = "0123456789";
 			buf[1] = fmt[u%10];
 			buf[2] = '.';
 		}
 		buf[3] = "0123456789"[v];
 		buf[4] = scale[idx]; /* typically scale = " kmgt..." */
 	}
 }


 // 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_unsigned_not_4(void);
 char* FAST_FUNC utoa_to_buf(unsigned n, char *buf, unsigned buflen)
 {
 	unsigned i, out, res;
 	if (sizeof(unsigned) != 4)
 		BUG_sizeof_unsigned_not_4();
 	if (buflen) {
 		out = 0;
 		for (i = 1000000000; i; i /= 10) {
 			res = n / i;
 			if (res || out || i == 1) {
 				if (!--buflen) break;
 				out++;
 				n -= res*i;
 				*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 && 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 null terminator, or 12 bytes.
 // It so happens that sizeof(int) * 3 is enough for 32+ bits.
 // (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))) = '\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))) = '\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;
 }

 /* 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

 /* 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 = { 0, 0, 0, 0 };
 	int ret = ioctl(fd, TIOCGWINSZ, &win);

 	if (height) {
 		if (!win.ws_row) {
 			char *s = getenv("LINES");
 			if (s) win.ws_row = atoi(s);
 		}
 		if (win.ws_row <= 1 || win.ws_row >= 30000)
 			win.ws_row = 24;
 		*height = (int) win.ws_row;
 	}

 	if (width) {
 		if (!win.ws_col) {
 			char *s = getenv("COLUMNS");
 			if (s) win.ws_col = atoi(s);
 		}
 		if (win.ws_col <= 1 || win.ws_col >= 30000)
 			win.ws_col = 80;
 		*width = (int) win.ws_col;
 	}

 	return ret;
 }

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

	/* Convert unsigned long long value into compact 4-char
	* representation. Examples: "1234", "1.2k", " 27M", "123T"
	* String is not terminated (buf[4] is untouched) */
	void FAST_FUNC smart_ulltoa4(unsigned long long ul, char buf[5], const char *scale)
	{
	const char *fmt;
	char c;
	unsigned v, u, idx = 0;

	if (ul > 9999) { // do not scale if 9999 or less
	ul *= 10;
	do {
	ul /= 1024;
	idx++;
	} while (ul >= 10000);
	}
	v = ul; // ullong divisions are expensive, avoid them

	fmt = " 123456789";
	u = v / 10;
	v = v % 10;
	if (!idx) {
	// 9999 or less: use "1234" format
	// u is value/10, v is last digit
	c = buf[0] = " 123456789"[u/100];
	if (c != ' ') fmt = "0123456789";
	c = buf[1] = fmt[u/10%10];
	if (c != ' ') fmt = "0123456789";
	buf[2] = fmt[u%10];
	buf[3] = "0123456789"[v];
	} else {
	// u is value, v is 1/10ths (allows for 9.2M format)
	if (u >= 10) {
	// value is >= 10: use "123M', " 12M" formats
	c = buf[0] = " 123456789"[u/100];
	if (c != ' ') fmt = "0123456789";
	v = u % 10;
	u = u / 10;
	buf[1] = fmt[u%10];
	} else {
	// value is < 10: use "9.2M" format
	buf[0] = "0123456789"[u];
	buf[1] = '.';
	}
	buf[2] = "0123456789"[v];
	buf[3] = scale[idx]; /* typically scale = " kmgt..." */
	}
	}

	/* Convert unsigned long long value into compact 5-char representation.
	* String is not terminated (buf[5] is untouched) */
	void FAST_FUNC smart_ulltoa5(unsigned long long ul, char buf[6], const char *scale)
	{
	const char *fmt;
	char c;
	unsigned v, u, idx = 0;

	if (ul > 99999) { // do not scale if 99999 or less
	ul *= 10;
	do {
	ul /= 1024;
	idx++;
	} while (ul >= 100000);
	}
	v = ul; // ullong divisions are expensive, avoid them

	fmt = " 123456789";
	u = v / 10;
	v = v % 10;
	if (!idx) {
	// 99999 or less: use "12345" format
	// u is value/10, v is last digit
	c = buf[0] = " 123456789"[u/1000];
	if (c != ' ') fmt = "0123456789";
	c = buf[1] = fmt[u/100%10];
	if (c != ' ') fmt = "0123456789";
	c = buf[2] = fmt[u/10%10];
	if (c != ' ') fmt = "0123456789";
	buf[3] = fmt[u%10];
	buf[4] = "0123456789"[v];
	} else {
	// value has been scaled into 0..9999.9 range
	// u is value, v is 1/10ths (allows for 92.1M format)
	if (u >= 100) {
	// value is >= 100: use "1234M', " 123M" formats
	c = buf[0] = " 123456789"[u/1000];
	if (c != ' ') fmt = "0123456789";
	c = buf[1] = fmt[u/100%10];
	if (c != ' ') fmt = "0123456789";
	v = u % 10;
	u = u / 10;
	buf[2] = fmt[u%10];
	} else {
	// value is < 100: use "92.1M" format
	c = buf[0] = " 123456789"[u/10];
	if (c != ' ') fmt = "0123456789";
	buf[1] = fmt[u%10];
	buf[2] = '.';
	}
	buf[3] = "0123456789"[v];
	buf[4] = scale[idx]; /* typically scale = " kmgt..." */
	}
	}


	// 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_unsigned_not_4(void);
	char* FAST_FUNC utoa_to_buf(unsigned n, char *buf, unsigned buflen)
	{
	unsigned i, out, res;
	if (sizeof(unsigned) != 4)
	BUG_sizeof_unsigned_not_4();
	if (buflen) {
	out = 0;
	for (i = 1000000000; i; i /= 10) {
	res = n / i;
	if (res \|\| out \|\| i == 1) {
	if (!--buflen) break;
	out++;
	n -= res*i;
	*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 && 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 null terminator, or 12 bytes.
	// It so happens that sizeof(int) * 3 is enough for 32+ bits.
	// (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))) = '\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))) = '\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;
	}

	/* 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

	/* 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 = { 0, 0, 0, 0 };
	int ret = ioctl(fd, TIOCGWINSZ, &win);

	if (height) {
	if (!win.ws_row) {
	char *s = getenv("LINES");
	if (s) win.ws_row = atoi(s);
	}
	if (win.ws_row <= 1 \|\| win.ws_row >= 30000)
	win.ws_row = 24;
	*height = (int) win.ws_row;
	}

	if (width) {
	if (!win.ws_col) {
	char *s = getenv("COLUMNS");
	if (s) win.ws_col = atoi(s);
	}
	if (win.ws_col <= 1 \|\| win.ws_col >= 30000)
	win.ws_col = 80;
	*width = (int) win.ws_col;
	}

	return ret;
	}

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