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 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 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 | if (value == 0) {
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241 | char *s = getenv(env_name);
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242 | if (s) {
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243 | value = atoi(s);
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244 | /* If LINES/COLUMNS are set, pretend that there is
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245 | * no error getting w/h, this prevents some ugly
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246 | * cursor tricks by our callers */
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247 | *err = 0;
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248 | }
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249 | }
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250 | if (value <= 1 || value >= 30000)
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251 | value = def_val;
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252 | return value;
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253 | }
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254 |
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255 | /* It is perfectly ok to pass in a NULL for either width or for
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256 | * height, in which case that value will not be set. */
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257 | int FAST_FUNC get_terminal_width_height(int fd, unsigned *width, unsigned *height)
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258 | {
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259 | struct winsize win;
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260 | int err;
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261 |
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262 | win.ws_row = 0;
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263 | win.ws_col = 0;
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264 | /* I've seen ioctl returning 0, but row/col is (still?) 0.
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265 | * We treat that as an error too. */
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266 | err = ioctl(fd, TIOCGWINSZ, &win) != 0 || win.ws_row == 0;
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267 | if (height)
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268 | *height = wh_helper(win.ws_row, 24, "LINES", &err);
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269 | if (width)
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270 | *width = wh_helper(win.ws_col, 80, "COLUMNS", &err);
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271 | return err;
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272 | }
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273 | int FAST_FUNC get_terminal_width(int fd)
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274 | {
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275 | unsigned width;
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276 | get_terminal_width_height(fd, &width, NULL);
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277 | return width;
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278 | }
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279 |
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280 | int FAST_FUNC tcsetattr_stdin_TCSANOW(const struct termios *tp)
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281 | {
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282 | return tcsetattr(STDIN_FILENO, TCSANOW, tp);
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283 | }
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284 |
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285 | pid_t FAST_FUNC safe_waitpid(pid_t pid, int *wstat, int options)
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286 | {
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287 | pid_t r;
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288 |
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289 | do
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290 | r = waitpid(pid, wstat, options);
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291 | while ((r == -1) && (errno == EINTR));
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292 | return r;
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293 | }
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294 |
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295 | pid_t FAST_FUNC wait_any_nohang(int *wstat)
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296 | {
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297 | return safe_waitpid(-1, wstat, WNOHANG);
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298 | }
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299 |
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300 | // Wait for the specified child PID to exit, returning child's error return.
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301 | int FAST_FUNC wait4pid(pid_t pid)
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302 | {
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303 | int status;
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304 |
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305 | if (pid <= 0) {
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306 | /*errno = ECHILD; -- wrong. */
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307 | /* we expect errno to be already set from failed [v]fork/exec */
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308 | return -1;
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309 | }
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310 | if (safe_waitpid(pid, &status, 0) == -1)
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311 | return -1;
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312 | if (WIFEXITED(status))
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313 | return WEXITSTATUS(status);
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314 | if (WIFSIGNALED(status))
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315 | return WTERMSIG(status) + 0x180;
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316 | return 0;
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317 | }
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318 |
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319 | // Useful when we do know that pid is valid, and we just want to wait
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320 | // for it to exit. Not existing pid is fatal. waitpid() status is not returned.
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321 | int FAST_FUNC wait_for_exitstatus(pid_t pid)
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322 | {
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323 | int exit_status, n;
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324 |
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325 | n = safe_waitpid(pid, &exit_status, 0);
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326 | if (n < 0)
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327 | bb_perror_msg_and_die("waitpid");
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328 | return exit_status;
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329 | }
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