busybox/libbb/xfuncs.c
2008-05-18 22:28:26 +00:00

292 lines
7.1 KiB
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 ndelay_on(int fd)
{
return fcntl(fd, F_SETFL, fcntl(fd,F_GETFL) | O_NONBLOCK);
}
int ndelay_off(int fd)
{
return fcntl(fd, F_SETFL, fcntl(fd,F_GETFL) & ~O_NONBLOCK);
}
int 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 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 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 *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 *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 *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 *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 *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 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 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;
}