432 lines
11 KiB
C
432 lines
11 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* Utility routines.
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*
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* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
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* Copyright (C) 2006 Rob Landley
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* Copyright (C) 2006 Denys Vlasenko
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*
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* Licensed under GPLv2, see file LICENSE in this source tree.
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*/
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/* We need to have separate xfuncs.c and xfuncs_printf.c because
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* with current linkers, even with section garbage collection,
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* if *.o module references any of XXXprintf functions, you pull in
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* entire printf machinery. Even if you do not use the function
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* which uses XXXprintf.
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*
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* xfuncs.c contains functions (not necessarily xfuncs)
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* which do not pull in printf, directly or indirectly.
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* xfunc_printf.c contains those which do.
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*
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* TODO: move xmalloc() and xatonum() here.
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*/
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#include "libbb.h"
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/* Turn on nonblocking I/O on a fd */
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int FAST_FUNC ndelay_on(int fd)
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{
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int flags = fcntl(fd, F_GETFL);
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if (flags & O_NONBLOCK)
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return flags;
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fcntl(fd, F_SETFL, flags | O_NONBLOCK);
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return flags;
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}
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int FAST_FUNC ndelay_off(int fd)
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{
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int flags = fcntl(fd, F_GETFL);
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if (!(flags & O_NONBLOCK))
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return flags;
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fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
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return flags;
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}
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void FAST_FUNC close_on_exec_on(int fd)
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{
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fcntl(fd, F_SETFD, FD_CLOEXEC);
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}
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char* FAST_FUNC strncpy_IFNAMSIZ(char *dst, const char *src)
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{
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#ifndef IFNAMSIZ
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enum { IFNAMSIZ = 16 };
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#endif
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return strncpy(dst, src, IFNAMSIZ);
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}
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/* Convert unsigned integer to ascii, writing into supplied buffer.
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* A truncated result contains the first few digits of the result ala strncpy.
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* Returns a pointer past last generated digit, does _not_ store NUL.
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*/
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char* FAST_FUNC utoa_to_buf(unsigned n, char *buf, unsigned buflen)
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{
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unsigned i, out, res;
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if (buflen) {
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out = 0;
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BUILD_BUG_ON(sizeof(n) != 4 && sizeof(n) != 8);
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if (sizeof(n) == 4)
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// 2^32-1 = 4294967295
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i = 1000000000;
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#if UINT_MAX > 0xffffffff /* prevents warning about "const too large" */
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else
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if (sizeof(n) == 8)
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// 2^64-1 = 18446744073709551615
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i = 10000000000000000000;
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#endif
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for (; i; i /= 10) {
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res = n / i;
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n = n % i;
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if (res || out || i == 1) {
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if (--buflen == 0)
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break;
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out++;
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*buf++ = '0' + res;
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}
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}
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}
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return buf;
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}
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/* Convert signed integer to ascii, like utoa_to_buf() */
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char* FAST_FUNC itoa_to_buf(int n, char *buf, unsigned buflen)
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{
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if (!buflen)
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return buf;
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if (n < 0) {
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n = -n;
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*buf++ = '-';
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buflen--;
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}
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return utoa_to_buf((unsigned)n, buf, buflen);
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}
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// The following two functions use a static buffer, so calling either one a
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// second time will overwrite previous results.
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//
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// The largest 32 bit integer is -2 billion plus NUL, or 1+10+1=12 bytes.
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// It so happens that sizeof(int) * 3 is enough for 32+ bit ints.
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// (sizeof(int) * 3 + 2 is correct for any width, even 8-bit)
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static char local_buf[sizeof(int) * 3];
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/* Convert unsigned integer to ascii using a static buffer (returned). */
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char* FAST_FUNC utoa(unsigned n)
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{
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*(utoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
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return local_buf;
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}
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/* Convert signed integer to ascii using a static buffer (returned). */
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char* FAST_FUNC itoa(int n)
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{
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*(itoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
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return local_buf;
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}
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/* Emit a string of hex representation of bytes */
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char* FAST_FUNC bin2hex(char *p, const char *cp, int count)
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{
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while (count) {
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unsigned char c = *cp++;
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/* put lowercase hex digits */
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*p++ = 0x20 | bb_hexdigits_upcase[c >> 4];
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*p++ = 0x20 | bb_hexdigits_upcase[c & 0xf];
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count--;
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}
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return p;
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}
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/* Convert "[x]x[:][x]x[:][x]x[:][x]x" hex string to binary, no more than COUNT bytes */
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char* FAST_FUNC hex2bin(char *dst, const char *str, int count)
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{
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errno = EINVAL;
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while (*str && count) {
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uint8_t val;
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uint8_t c = *str++;
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if (isdigit(c))
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val = c - '0';
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else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
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val = (c|0x20) - ('a' - 10);
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else
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return NULL;
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val <<= 4;
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c = *str;
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if (isdigit(c))
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val |= c - '0';
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else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
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val |= (c|0x20) - ('a' - 10);
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else if (c == ':' || c == '\0')
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val >>= 4;
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else
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return NULL;
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*dst++ = val;
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if (c != '\0')
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str++;
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if (*str == ':')
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str++;
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count--;
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}
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errno = (*str ? ERANGE : 0);
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return dst;
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}
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/* Return how long the file at fd is, if there's any way to determine it. */
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#ifdef UNUSED
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off_t FAST_FUNC fdlength(int fd)
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{
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off_t bottom = 0, top = 0, pos;
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long size;
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// If the ioctl works for this, return it.
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if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
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// FIXME: explain why lseek(SEEK_END) is not used here!
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// If not, do a binary search for the last location we can read. (Some
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// block devices don't do BLKGETSIZE right.)
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do {
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char temp;
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pos = bottom + (top - bottom) / 2;
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// If we can read from the current location, it's bigger.
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if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) {
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if (bottom == top) bottom = top = (top+1) * 2;
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else bottom = pos;
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// If we can't, it's smaller.
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} else {
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if (bottom == top) {
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if (!top) return 0;
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bottom = top/2;
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}
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else top = pos;
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}
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} while (bottom + 1 != top);
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return pos + 1;
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}
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#endif
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int FAST_FUNC bb_putchar_stderr(char ch)
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{
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return write(STDERR_FILENO, &ch, 1);
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}
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ssize_t FAST_FUNC full_write1_str(const char *str)
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{
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return full_write(STDOUT_FILENO, str, strlen(str));
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}
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ssize_t FAST_FUNC full_write2_str(const char *str)
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{
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return full_write(STDERR_FILENO, str, strlen(str));
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}
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static int wh_helper(int value, int def_val, const char *env_name, int *err)
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{
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/* Envvars override even if "value" from ioctl is valid (>0).
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* Rationale: it's impossible to guess what user wants.
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* For example: "man CMD | ...": should "man" format output
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* to stdout's width? stdin's width? /dev/tty's width? 80 chars?
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* We _cant_ know it. If "..." saves text for e.g. email,
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* then it's probably 80 chars.
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* If "..." is, say, "grep -v DISCARD | $PAGER", then user
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* would prefer his tty's width to be used!
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*
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* Since we don't know, at least allow user to do this:
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* "COLUMNS=80 man CMD | ..."
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*/
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char *s = getenv(env_name);
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if (s) {
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value = atoi(s);
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/* If LINES/COLUMNS are set, pretend that there is
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* no error getting w/h, this prevents some ugly
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* cursor tricks by our callers */
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*err = 0;
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}
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if (value <= 1 || value >= 30000)
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value = def_val;
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return value;
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}
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/* It is perfectly ok to pass in a NULL for either width or for
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* height, in which case that value will not be set. */
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int FAST_FUNC get_terminal_width_height(int fd, unsigned *width, unsigned *height)
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{
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struct winsize win;
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int err;
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int close_me = -1;
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if (fd == -1) {
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if (isatty(STDOUT_FILENO))
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fd = STDOUT_FILENO;
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else
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if (isatty(STDERR_FILENO))
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fd = STDERR_FILENO;
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else
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if (isatty(STDIN_FILENO))
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fd = STDIN_FILENO;
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else
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close_me = fd = open("/dev/tty", O_RDONLY);
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}
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win.ws_row = 0;
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win.ws_col = 0;
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/* I've seen ioctl returning 0, but row/col is (still?) 0.
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* We treat that as an error too. */
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err = ioctl(fd, TIOCGWINSZ, &win) != 0 || win.ws_row == 0;
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if (height)
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*height = wh_helper(win.ws_row, 24, "LINES", &err);
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if (width)
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*width = wh_helper(win.ws_col, 80, "COLUMNS", &err);
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if (close_me >= 0)
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close(close_me);
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return err;
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}
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int FAST_FUNC get_terminal_width(int fd)
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{
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unsigned width;
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get_terminal_width_height(fd, &width, NULL);
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return width;
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}
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int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp)
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{
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return tcsetattr(STDIN_FILENO, TCSANOW, tp);
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}
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int FAST_FUNC get_termios_and_make_raw(int fd, struct termios *newterm, struct termios *oldterm, int flags)
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{
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//TODO: slattach, shell read might be adapted to use this too: grep for "tcsetattr", "[VTIME] = 0"
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int r;
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memset(oldterm, 0, sizeof(*oldterm)); /* paranoia */
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r = tcgetattr(fd, oldterm);
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*newterm = *oldterm;
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/* Turn off buffered input (ICANON)
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* Turn off echoing (ECHO)
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* and separate echoing of newline (ECHONL, normally off anyway)
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*/
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newterm->c_lflag &= ~(ICANON | ECHO | ECHONL);
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if (flags & TERMIOS_CLEAR_ISIG) {
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/* dont recognize INT/QUIT/SUSP chars */
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newterm->c_lflag &= ~ISIG;
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}
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/* reads will block only if < 1 char is available */
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newterm->c_cc[VMIN] = 1;
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/* no timeout (reads block forever) */
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newterm->c_cc[VTIME] = 0;
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/* IXON, IXOFF, and IXANY:
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* IXOFF=1: sw flow control is enabled on input queue:
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* tty transmits a STOP char when input queue is close to full
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* and transmits a START char when input queue is nearly empty.
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* IXON=1: sw flow control is enabled on output queue:
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* tty will stop sending if STOP char is received,
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* and resume sending if START is received, or if any char
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* is received and IXANY=1.
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*/
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if (flags & TERMIOS_RAW_CRNL_INPUT) {
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/* IXON=0: XON/XOFF chars are treated as normal chars (why we do this?) */
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/* dont convert CR to NL on input */
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newterm->c_iflag &= ~(IXON | ICRNL);
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}
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if (flags & TERMIOS_RAW_CRNL_OUTPUT) {
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/* dont convert NL to CR+NL on output */
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newterm->c_oflag &= ~(ONLCR);
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/* Maybe clear more c_oflag bits? Usually, only OPOST and ONLCR are set.
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* OPOST Enable output processing (reqd for OLCUC and *NL* bits to work)
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* OLCUC Map lowercase characters to uppercase on output.
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* OCRNL Map CR to NL on output.
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* ONOCR Don't output CR at column 0.
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* ONLRET Don't output CR.
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*/
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}
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if (flags & TERMIOS_RAW_INPUT) {
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#ifndef IMAXBEL
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# define IMAXBEL 0
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#endif
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#ifndef IUCLC
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# define IUCLC 0
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#endif
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#ifndef IXANY
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# define IXANY 0
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#endif
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/* IXOFF=0: disable sending XON/XOFF if input buf is full
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* IXON=0: input XON/XOFF chars are not special
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* BRKINT=0: dont send SIGINT on break
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* IMAXBEL=0: dont echo BEL on input line too long
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* INLCR,ICRNL,IUCLC: dont convert anything on input
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*/
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newterm->c_iflag &= ~(IXOFF|IXON|IXANY|BRKINT|INLCR|ICRNL|IUCLC|IMAXBEL);
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}
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return r;
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}
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int FAST_FUNC set_termios_to_raw(int fd, struct termios *oldterm, int flags)
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{
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struct termios newterm;
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get_termios_and_make_raw(fd, &newterm, oldterm, flags);
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return tcsetattr(fd, TCSANOW, &newterm);
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}
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pid_t FAST_FUNC safe_waitpid(pid_t pid, int *wstat, int options)
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{
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pid_t r;
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do
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r = waitpid(pid, wstat, options);
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while ((r == -1) && (errno == EINTR));
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return r;
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}
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pid_t FAST_FUNC wait_any_nohang(int *wstat)
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{
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return safe_waitpid(-1, wstat, WNOHANG);
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}
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// Wait for the specified child PID to exit, returning child's error return.
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int FAST_FUNC wait4pid(pid_t pid)
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{
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int status;
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if (pid <= 0) {
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/*errno = ECHILD; -- wrong. */
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/* we expect errno to be already set from failed [v]fork/exec */
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return -1;
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}
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if (safe_waitpid(pid, &status, 0) == -1)
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return -1;
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if (WIFEXITED(status))
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return WEXITSTATUS(status);
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if (WIFSIGNALED(status))
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return WTERMSIG(status) + 0x180;
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return 0;
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}
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// Useful when we do know that pid is valid, and we just want to wait
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// for it to exit. Not existing pid is fatal. waitpid() status is not returned.
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int FAST_FUNC wait_for_exitstatus(pid_t pid)
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{
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int exit_status, n;
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n = safe_waitpid(pid, &exit_status, 0);
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if (n < 0)
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bb_perror_msg_and_die("waitpid");
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return exit_status;
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}
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