[279] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /*
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| 3 | * Utility routines.
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| 4 | *
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| 5 | * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
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| 6 | * Copyright (C) 2006 Rob Landley
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| 7 | * Copyright (C) 2006 Denys Vlasenko
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| 8 | *
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| 9 | * Licensed under GPLv2, see file LICENSE in this source tree.
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| 10 | */
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| 11 |
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| 12 | /* We need to have separate xfuncs.c and xfuncs_printf.c because
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| 13 | * with current linkers, even with section garbage collection,
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| 14 | * if *.o module references any of XXXprintf functions, you pull in
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| 15 | * entire printf machinery. Even if you do not use the function
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| 16 | * which uses XXXprintf.
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| 17 | *
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| 18 | * xfuncs.c contains functions (not necessarily xfuncs)
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| 19 | * which do not pull in printf, directly or indirectly.
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| 20 | * xfunc_printf.c contains those which do.
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| 21 | *
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| 22 | * TODO: move xmalloc() and xatonum() here.
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| 23 | */
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| 24 |
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| 25 | #include "libbb.h"
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| 26 |
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| 27 | /* Turn on nonblocking I/O on a fd */
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| 28 | int FAST_FUNC ndelay_on(int fd)
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| 29 | {
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| 30 | int flags = fcntl(fd, F_GETFL);
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| 31 | if (flags & O_NONBLOCK)
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| 32 | return flags;
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| 33 | fcntl(fd, F_SETFL, flags | O_NONBLOCK);
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| 34 | return flags;
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| 35 | }
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| 36 |
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| 37 | int FAST_FUNC ndelay_off(int fd)
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| 38 | {
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| 39 | int flags = fcntl(fd, F_GETFL);
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| 40 | if (!(flags & O_NONBLOCK))
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| 41 | return flags;
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| 42 | fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
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| 43 | return flags;
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| 44 | }
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| 45 |
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| 46 | void FAST_FUNC close_on_exec_on(int fd)
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| 47 | {
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| 48 | fcntl(fd, F_SETFD, FD_CLOEXEC);
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| 49 | }
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| 50 |
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| 51 | char* FAST_FUNC strncpy_IFNAMSIZ(char *dst, const char *src)
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| 52 | {
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| 53 | #ifndef IFNAMSIZ
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| 54 | enum { IFNAMSIZ = 16 };
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| 55 | #endif
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| 56 | return strncpy(dst, src, IFNAMSIZ);
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| 57 | }
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| 58 |
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| 59 |
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| 60 | /* Convert unsigned integer to ascii, writing into supplied buffer.
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| 61 | * A truncated result contains the first few digits of the result ala strncpy.
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| 62 | * Returns a pointer past last generated digit, does _not_ store NUL.
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| 63 | */
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| 64 | void BUG_sizeof(void);
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| 65 | char* FAST_FUNC utoa_to_buf(unsigned n, char *buf, unsigned buflen)
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| 66 | {
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| 67 | unsigned i, out, res;
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| 68 |
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| 69 | if (buflen) {
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| 70 | out = 0;
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| 71 | if (sizeof(n) == 4)
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| 72 | // 2^32-1 = 4294967295
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| 73 | i = 1000000000;
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| 74 | #if UINT_MAX > 4294967295 /* prevents warning about "const too large" */
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| 75 | else
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| 76 | if (sizeof(n) == 8)
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| 77 | // 2^64-1 = 18446744073709551615
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| 78 | i = 10000000000000000000;
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| 79 | #endif
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| 80 | else
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| 81 | BUG_sizeof();
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| 82 | for (; i; i /= 10) {
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| 83 | res = n / i;
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| 84 | n = n % i;
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| 85 | if (res || out || i == 1) {
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| 86 | if (--buflen == 0)
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| 87 | break;
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| 88 | out++;
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| 89 | *buf++ = '0' + res;
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| 90 | }
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| 91 | }
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| 92 | }
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| 93 | return buf;
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| 94 | }
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| 95 |
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| 96 | /* Convert signed integer to ascii, like utoa_to_buf() */
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| 97 | char* FAST_FUNC itoa_to_buf(int n, char *buf, unsigned buflen)
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| 98 | {
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| 99 | if (!buflen)
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| 100 | return buf;
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| 101 | if (n < 0) {
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| 102 | n = -n;
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| 103 | *buf++ = '-';
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| 104 | buflen--;
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| 105 | }
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| 106 | return utoa_to_buf((unsigned)n, buf, buflen);
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| 107 | }
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| 108 |
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| 109 | // The following two functions use a static buffer, so calling either one a
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| 110 | // second time will overwrite previous results.
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| 111 | //
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| 112 | // The largest 32 bit integer is -2 billion plus NUL, or 1+10+1=12 bytes.
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| 113 | // It so happens that sizeof(int) * 3 is enough for 32+ bit ints.
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| 114 | // (sizeof(int) * 3 + 2 is correct for any width, even 8-bit)
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| 115 |
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| 116 | static char local_buf[sizeof(int) * 3];
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| 117 |
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| 118 | /* Convert unsigned integer to ascii using a static buffer (returned). */
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| 119 | char* FAST_FUNC bb_utoa(unsigned n)
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| 120 | {
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| 121 | *(utoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
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| 122 |
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| 123 | return local_buf;
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| 124 | }
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| 125 |
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| 126 | /* Convert signed integer to ascii using a static buffer (returned). */
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| 127 | char* FAST_FUNC bb_itoa(int n)
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| 128 | {
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| 129 | *(itoa_to_buf(n, local_buf, sizeof(local_buf) - 1)) = '\0';
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| 130 |
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| 131 | return local_buf;
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| 132 | }
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| 133 |
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| 134 | /* Emit a string of hex representation of bytes */
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| 135 | char* FAST_FUNC bin2hex(char *p, const char *cp, int count)
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| 136 | {
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| 137 | while (count) {
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| 138 | unsigned char c = *cp++;
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| 139 | /* put lowercase hex digits */
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| 140 | *p++ = 0x20 | bb_hexdigits_upcase[c >> 4];
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| 141 | *p++ = 0x20 | bb_hexdigits_upcase[c & 0xf];
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| 142 | count--;
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| 143 | }
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| 144 | return p;
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| 145 | }
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| 146 |
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| 147 | /* Convert "[x]x[:][x]x[:][x]x[:][x]x" hex string to binary, no more than COUNT bytes */
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| 148 | char* FAST_FUNC hex2bin(char *dst, const char *str, int count)
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| 149 | {
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| 150 | errno = EINVAL;
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| 151 | while (*str && count) {
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| 152 | uint8_t val;
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| 153 | uint8_t c = *str++;
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| 154 | if (isdigit(c))
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| 155 | val = c - '0';
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| 156 | else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
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| 157 | val = (c|0x20) - ('a' - 10);
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| 158 | else
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| 159 | return NULL;
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| 160 | val <<= 4;
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| 161 | c = *str;
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| 162 | if (isdigit(c))
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| 163 | val |= c - '0';
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| 164 | else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
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| 165 | val |= (c|0x20) - ('a' - 10);
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| 166 | else if (c == ':' || c == '\0')
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| 167 | val >>= 4;
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| 168 | else
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| 169 | return NULL;
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| 170 |
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| 171 | *dst++ = val;
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| 172 | if (c != '\0')
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| 173 | str++;
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| 174 | if (*str == ':')
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| 175 | str++;
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| 176 | count--;
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| 177 | }
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| 178 | errno = (*str ? ERANGE : 0);
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| 179 | return dst;
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| 180 | }
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| 181 |
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| 182 | /* Return how long the file at fd is, if there's any way to determine it. */
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| 183 | #ifdef UNUSED
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| 184 | off_t FAST_FUNC fdlength(int fd)
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| 185 | {
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| 186 | off_t bottom = 0, top = 0, pos;
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| 187 | long size;
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| 188 |
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| 189 | // If the ioctl works for this, return it.
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| 190 |
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| 191 | if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
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| 192 |
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| 193 | // FIXME: explain why lseek(SEEK_END) is not used here!
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| 194 |
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| 195 | // If not, do a binary search for the last location we can read. (Some
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| 196 | // block devices don't do BLKGETSIZE right.)
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| 197 |
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| 198 | do {
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| 199 | char temp;
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| 200 |
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| 201 | pos = bottom + (top - bottom) / 2;
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| 202 |
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| 203 | // If we can read from the current location, it's bigger.
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| 204 |
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| 205 | if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) {
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| 206 | if (bottom == top) bottom = top = (top+1) * 2;
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| 207 | else bottom = pos;
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| 208 |
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| 209 | // If we can't, it's smaller.
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| 210 | } else {
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| 211 | if (bottom == top) {
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| 212 | if (!top) return 0;
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| 213 | bottom = top/2;
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| 214 | }
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| 215 | else top = pos;
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| 216 | }
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| 217 | } while (bottom + 1 != top);
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| 218 |
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| 219 | return pos + 1;
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| 220 | }
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| 221 | #endif
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| 222 |
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| 223 | int FAST_FUNC bb_putchar_stderr(char ch)
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| 224 | {
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| 225 | return write(STDERR_FILENO, &ch, 1);
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| 226 | }
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| 227 |
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| 228 | ssize_t FAST_FUNC full_write1_str(const char *str)
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| 229 | {
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| 230 | return full_write(STDOUT_FILENO, str, strlen(str));
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| 231 | }
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| 232 |
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| 233 | ssize_t FAST_FUNC full_write2_str(const char *str)
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| 234 | {
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| 235 | return full_write(STDERR_FILENO, str, strlen(str));
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| 236 | }
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| 237 |
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| 238 | static int wh_helper(int value, int def_val, const char *env_name, int *err)
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| 239 | {
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| 240 | /* Envvars override even if "value" from ioctl is valid (>0).
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| 241 | * Rationale: it's impossible to guess what user wants.
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| 242 | * For example: "man CMD | ...": should "man" format output
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| 243 | * to stdout's width? stdin's width? /dev/tty's width? 80 chars?
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| 244 | * We _cant_ know it. If "..." saves text for e.g. email,
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| 245 | * then it's probably 80 chars.
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| 246 | * If "..." is, say, "grep -v DISCARD | $PAGER", then user
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| 247 | * would prefer his tty's width to be used!
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| 248 | *
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| 249 | * Since we don't know, at least allow user to do this:
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| 250 | * "COLUMNS=80 man CMD | ..."
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| 251 | */
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| 252 | char *s = getenv(env_name);
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| 253 | if (s) {
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| 254 | value = atoi(s);
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| 255 | /* If LINES/COLUMNS are set, pretend that there is
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| 256 | * no error getting w/h, this prevents some ugly
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| 257 | * cursor tricks by our callers */
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| 258 | *err = 0;
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| 259 | }
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| 260 |
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| 261 | if (value <= 1 || value >= 30000)
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| 262 | value = def_val;
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| 263 | return value;
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| 264 | }
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| 265 |
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| 266 | /* It is perfectly ok to pass in a NULL for either width or for
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| 267 | * height, in which case that value will not be set. */
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| 268 | int FAST_FUNC get_terminal_width_height(int fd, unsigned *width, unsigned *height)
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| 269 | {
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| 270 | struct winsize win;
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| 271 | int err;
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| 272 | int close_me = -1;
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| 273 |
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| 274 | if (fd == -1) {
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| 275 | if (isatty(STDOUT_FILENO))
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| 276 | fd = STDOUT_FILENO;
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| 277 | else
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| 278 | if (isatty(STDERR_FILENO))
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| 279 | fd = STDERR_FILENO;
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| 280 | else
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| 281 | if (isatty(STDIN_FILENO))
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| 282 | fd = STDIN_FILENO;
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| 283 | else
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| 284 | close_me = fd = open("/dev/tty", O_RDONLY);
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| 285 | }
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| 286 |
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| 287 | win.ws_row = 0;
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| 288 | win.ws_col = 0;
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| 289 | /* I've seen ioctl returning 0, but row/col is (still?) 0.
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| 290 | * We treat that as an error too. */
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| 291 | err = ioctl(fd, TIOCGWINSZ, &win) != 0 || win.ws_row == 0;
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| 292 | if (height)
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| 293 | *height = wh_helper(win.ws_row, 24, "LINES", &err);
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| 294 | if (width)
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| 295 | *width = wh_helper(win.ws_col, 80, "COLUMNS", &err);
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| 296 |
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| 297 | if (close_me >= 0)
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| 298 | close(close_me);
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| 299 |
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| 300 | return err;
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| 301 | }
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| 302 | int FAST_FUNC get_terminal_width(int fd)
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| 303 | {
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| 304 | unsigned width;
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| 305 | get_terminal_width_height(fd, &width, NULL);
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| 306 | return width;
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| 307 | }
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| 308 |
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| 309 | int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp)
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| 310 | {
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| 311 | return tcsetattr(STDIN_FILENO, TCSANOW, tp);
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| 312 | }
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| 313 |
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| 314 | pid_t FAST_FUNC safe_waitpid(pid_t pid, int *wstat, int options)
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| 315 | {
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| 316 | pid_t r;
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| 317 |
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| 318 | do
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| 319 | r = waitpid(pid, wstat, options);
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| 320 | while ((r == -1) && (errno == EINTR));
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| 321 | return r;
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| 322 | }
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| 323 |
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| 324 | pid_t FAST_FUNC wait_any_nohang(int *wstat)
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| 325 | {
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| 326 | return safe_waitpid(-1, wstat, WNOHANG);
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| 327 | }
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| 328 |
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| 329 | // Wait for the specified child PID to exit, returning child's error return.
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| 330 | int FAST_FUNC wait4pid(pid_t pid)
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| 331 | {
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| 332 | int status;
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| 333 |
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| 334 | if (pid <= 0) {
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| 335 | /*errno = ECHILD; -- wrong. */
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| 336 | /* we expect errno to be already set from failed [v]fork/exec */
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| 337 | return -1;
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| 338 | }
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| 339 | if (safe_waitpid(pid, &status, 0) == -1)
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| 340 | return -1;
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| 341 | if (WIFEXITED(status))
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| 342 | return WEXITSTATUS(status);
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| 343 | if (WIFSIGNALED(status))
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| 344 | return WTERMSIG(status) + 0x180;
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| 345 | return 0;
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| 346 | }
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| 347 |
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| 348 | // Useful when we do know that pid is valid, and we just want to wait
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| 349 | // for it to exit. Not existing pid is fatal. waitpid() status is not returned.
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| 350 | int FAST_FUNC wait_for_exitstatus(pid_t pid)
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| 351 | {
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| 352 | int exit_status, n;
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| 353 |
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| 354 | n = safe_waitpid(pid, &exit_status, 0);
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| 355 | if (n < 0)
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| 356 | bb_perror_msg_and_die("waitpid");
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| 357 | return exit_status;
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| 358 | }
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