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| 1 | .\" Copyright (c) 1990, 1991 The Regents of the University of California. | ||
| 2 | .\" All rights reserved. | ||
| 3 | .\" | ||
| 4 | .\" This code is derived from software contributed to Berkeley by | ||
| 5 | .\" Chris Torek and the American National Standards Committee X3, | ||
| 6 | .\" on Information Processing Systems. | ||
| 7 | .\" | ||
| 8 | .\" Redistribution and use in source and binary forms, with or without | ||
| 9 | .\" modification, are permitted provided that the following conditions | ||
| 10 | .\" are met: | ||
| 11 | .\" 1. Redistributions of source code must retain the above copyright | ||
| 12 | .\" notice, this list of conditions and the following disclaimer. | ||
| 13 | .\" 2. Redistributions in binary form must reproduce the above copyright | ||
| 14 | .\" notice, this list of conditions and the following disclaimer in the | ||
| 15 | .\" documentation and/or other materials provided with the distribution. | ||
| 16 | .\" 3. Neither the name of the University nor the names of its contributors | ||
| 17 | .\" may be used to endorse or promote products derived from this software | ||
| 18 | .\" without specific prior written permission. | ||
| 19 | .\" | ||
| 20 | .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | ||
| 21 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
| 22 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | ||
| 23 | .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | ||
| 24 | .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | ||
| 25 | .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | ||
| 26 | .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | ||
| 27 | .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | ||
| 28 | .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | ||
| 29 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | ||
| 30 | .\" SUCH DAMAGE. | ||
| 31 | .\" | ||
| 32 | .\" $OpenBSD: strtoul.3,v 1.15 2003/06/02 20:18:38 millert Exp $ | ||
| 33 | .\" | ||
| 34 | .Dd June 25, 1992 | ||
| 35 | .Dt STRTOUL 3 | ||
| 36 | .Os | ||
| 37 | .Sh NAME | ||
| 38 | .Nm strtoul , | ||
| 39 | .Nm strtoull , | ||
| 40 | .Nm strtouq | ||
| 41 | .Nd "convert a string to an unsigned long or unsigned long long integer" | ||
| 42 | .Sh SYNOPSIS | ||
| 43 | .Fd #include <stdlib.h> | ||
| 44 | .Fd #include <limits.h> | ||
| 45 | .Ft unsigned long | ||
| 46 | .Fn strtoul "const char *nptr" "char **endptr" "int base" | ||
| 47 | .Pp | ||
| 48 | .Fd #include <stdlib.h> | ||
| 49 | .Fd #include <limits.h> | ||
| 50 | .Ft unsigned long long | ||
| 51 | .Fn strtoull "const char *nptr" "char **endptr" "int base" | ||
| 52 | .Pp | ||
| 53 | .Fd #include <sys/types.h> | ||
| 54 | .Fd #include <stdlib.h> | ||
| 55 | .Fd #include <limits.h> | ||
| 56 | .Ft u_quad_t | ||
| 57 | .Fn strtouq "const char *nptr" "char **endptr" "int base" | ||
| 58 | .Sh DESCRIPTION | ||
| 59 | The | ||
| 60 | .Fn strtoul | ||
| 61 | function converts the string in | ||
| 62 | .Fa nptr | ||
| 63 | to an | ||
| 64 | .Li unsigned long | ||
| 65 | value. | ||
| 66 | The | ||
| 67 | .Fn strtoull | ||
| 68 | function converts the string in | ||
| 69 | .Fa nptr | ||
| 70 | to an | ||
| 71 | .Li unsigned long long | ||
| 72 | value. | ||
| 73 | The | ||
| 74 | .Fn strtouq | ||
| 75 | function is a deprecated equivalent of | ||
| 76 | .Fn strtoull | ||
| 77 | and is provided for backwards compatibility with legacy programs. | ||
| 78 | The conversion is done according to the given | ||
| 79 | .Fa base , | ||
| 80 | which must be a number between 2 and 36 inclusive | ||
| 81 | or the special value 0. | ||
| 82 | If the string in | ||
| 83 | .Fa nptr | ||
| 84 | represents a negative number, it will be converted to its unsigned equivalent. | ||
| 85 | This behavior is consistent with what happens when a signed integer type is | ||
| 86 | cast to its unsigned counterpart. | ||
| 87 | .Pp | ||
| 88 | The string may begin with an arbitrary amount of whitespace | ||
| 89 | (as determined by | ||
| 90 | .Xr isspace 3 ) | ||
| 91 | followed by a single optional | ||
| 92 | .Ql + | ||
| 93 | or | ||
| 94 | .Ql - | ||
| 95 | sign. | ||
| 96 | If | ||
| 97 | .Fa base | ||
| 98 | is zero or 16, the string may then include a | ||
| 99 | .Ql 0x | ||
| 100 | prefix, and the number will be read in base 16; otherwise, a zero | ||
| 101 | .Fa base | ||
| 102 | is taken as 10 (decimal) unless the next character is | ||
| 103 | .Ql 0 , | ||
| 104 | in which case it is taken as 8 (octal). | ||
| 105 | .Pp | ||
| 106 | The remainder of the string is converted to an | ||
| 107 | .Li unsigned long | ||
| 108 | value in the obvious manner, stopping at the end of the string | ||
| 109 | or at the first character that does not produce a valid digit | ||
| 110 | in the given base. | ||
| 111 | (In bases above 10, the letter | ||
| 112 | .Ql A | ||
| 113 | in either upper or lower case represents 10, | ||
| 114 | .Ql B | ||
| 115 | represents 11, and so forth, with | ||
| 116 | .Ql Z | ||
| 117 | representing 35.) | ||
| 118 | .Pp | ||
| 119 | If | ||
| 120 | .Fa endptr | ||
| 121 | is non-null, | ||
| 122 | .Fn strtoul | ||
| 123 | stores the address of the first invalid character in | ||
| 124 | .Fa *endptr . | ||
| 125 | If there were no digits at all, however, | ||
| 126 | .Fn strtoul | ||
| 127 | stores the original value of | ||
| 128 | .Fa nptr | ||
| 129 | in | ||
| 130 | .Fa *endptr . | ||
| 131 | (Thus, if | ||
| 132 | .Fa *nptr | ||
| 133 | is not | ||
| 134 | .Ql \e0 | ||
| 135 | but | ||
| 136 | .Fa **endptr | ||
| 137 | is | ||
| 138 | .Ql \e0 | ||
| 139 | on return, the entire string was valid.) | ||
| 140 | .Sh RETURN VALUES | ||
| 141 | The | ||
| 142 | .Fn strtoul | ||
| 143 | function returns the result of the conversion, | ||
| 144 | unless the value would overflow, in which case | ||
| 145 | .Dv ULONG_MAX | ||
| 146 | is returned and | ||
| 147 | .Va errno | ||
| 148 | is set to | ||
| 149 | .Er ERANGE . | ||
| 150 | If there was a leading minus sign, | ||
| 151 | .Fn strtoul | ||
| 152 | returns the (unsigned) negation of the absolute value of the number, unless | ||
| 153 | the absolute value would overflow. | ||
| 154 | In this case, | ||
| 155 | .Fn strtoul | ||
| 156 | returns | ||
| 157 | .Dv ULONG_MAX | ||
| 158 | and sets the global variable | ||
| 159 | .Va errno | ||
| 160 | to | ||
| 161 | .Er ERANGE . | ||
| 162 | .Pp | ||
| 163 | The | ||
| 164 | .Fn strtoull | ||
| 165 | function has identical return values except that | ||
| 166 | .Dv ULLONG_MAX | ||
| 167 | is used to indicate overflow. | ||
| 168 | .Pp | ||
| 169 | There is no way to determine if | ||
| 170 | .Fn strtoul | ||
| 171 | has processed a negative number (and returned an unsigned value) short of | ||
| 172 | examining the string in | ||
| 173 | .Fa nptr | ||
| 174 | directly. | ||
| 175 | .Sh EXAMPLES | ||
| 176 | Ensuring that a string is a valid number (i.e., in range and containing no | ||
| 177 | trailing characters) requires clearing | ||
| 178 | .Va errno | ||
| 179 | beforehand explicitly since | ||
| 180 | .Va errno | ||
| 181 | is not changed on a successful call to | ||
| 182 | .Fn strtoul , | ||
| 183 | and the return value of | ||
| 184 | .Fn strtoul | ||
| 185 | cannot be used unambiguously to signal an error: | ||
| 186 | .Bd -literal -offset indent | ||
| 187 | char *ep; | ||
| 188 | unsigned long ulval; | ||
| 189 | |||
| 190 | \&... | ||
| 191 | |||
| 192 | errno = 0; | ||
| 193 | ulval = strtoul(buf, &ep, 10); | ||
| 194 | if (buf[0] == '\e0' || *ep != '\e0') | ||
| 195 | goto not_a_number; | ||
| 196 | if (errno == ERANGE && ulval == ULONG_MAX) | ||
| 197 | goto out_of_range; | ||
| 198 | .Ed | ||
| 199 | .Pp | ||
| 200 | This example will accept | ||
| 201 | .Dq 12 | ||
| 202 | but not | ||
| 203 | .Dq 12foo | ||
| 204 | or | ||
| 205 | .Dq 12\en . | ||
| 206 | If trailing whitespace is acceptable, further checks must be done on | ||
| 207 | .Va *ep ; | ||
| 208 | alternately, use | ||
| 209 | .Xr sscanf 3 . | ||
| 210 | .Sh ERRORS | ||
| 211 | .Bl -tag -width Er | ||
| 212 | .It Bq Er ERANGE | ||
| 213 | The given string was out of range; the value converted has been clamped. | ||
| 214 | .El | ||
| 215 | .Sh SEE ALSO | ||
| 216 | .Xr sscanf 3 , | ||
| 217 | .Xr strtol 3 | ||
| 218 | .Sh STANDARDS | ||
| 219 | The | ||
| 220 | .Fn strtoul | ||
| 221 | and | ||
| 222 | .Fn strtoull | ||
| 223 | functions conform to | ||
| 224 | .St -ansiC-99 . | ||
| 225 | The | ||
| 226 | .Fn strtouq | ||
| 227 | function is a | ||
| 228 | .Bx | ||
| 229 | extension and is provided for backwards compatibility with legacy programs. | ||
| 230 | .Sh BUGS | ||
| 231 | Ignores the current locale. | ||
