stdlib/strtol.3

   1 .\" Copyright (c) 1990, 1991, 1993
   2 .\"     The Regents of the University of California.  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. All advertising materials mentioning features or use of this software
  17 .\"    must display the following acknowledgement:
  18 .\"     This product includes software developed by the University of
  19 .\"     California, Berkeley and its contributors.
  20 .\" 4. Neither the name of the University nor the names of its contributors
  21 .\"    may be used to endorse or promote products derived from this software
  22 .\"    without specific prior written permission.
  23 .\"
  24 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27 .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34 .\" SUCH DAMAGE.
  35 .\"
  36 .\"     @(#)strtol.3    8.1 (Berkeley) 6/4/93
  37 .\" $FreeBSD: src/lib/libc/stdlib/strtol.3,v 1.20 2005/01/22 18:02:58 ache Exp $
  38 .\"
  39 .Dd November 28, 2001
  40 .Dt STRTOL 3
  41 .Os
  42 .Sh NAME
  43 .Nm strtoimax ,
  44 .Nm strtol ,
  45 .Nm strtoll ,
  46 .Nm strtoq
  47 .Nd "convert a string value to a"
  48 .Vt long , "long long" , intmax_t
  49 or
  50 .Vt quad_t
  51 integer
  52 .Sh LIBRARY
  53 .Lb libc
  54 .Sh SYNOPSIS
  55 .In inttypes.h
  56 .Ft intmax_t
  57 .Fo strtoimax
  58 .Fa "const char *restrict str"
  59 .Fa "char **restrict endptr"
  60 .Fa "int base"
  61 .Fc
  62 .In stdlib.h
  63 .Ft long
  64 .Fo strtol
  65 .Fa "const char *restrict str"
  66 .Fa "char **restrict endptr"
  67 .Fa "int base"
  68 .Fc
  69 .Ft long long
  70 .Fo strtoll
  71 .Fa "const char *restrict str"
  72 .Fa "char **restrict endptr"
  73 .Fa "int base"
  74 .Fc
  75 .In sys/types.h
  76 .In stdlib.h
  77 .In limits.h
  78 .Ft quad_t
  79 .Fo strtoq
  80 .Fa "const char *str"
  81 .Fa "char **endptr"
  82 .Fa "int base"
  83 .Fc
  84 .Sh DESCRIPTION
  85 The
  86 .Fn strtol
  87 function
  88 converts the string in
  89 .Fa str
  90 to a
  91 .Vt long
  92 value.
  93 The
  94 .Fn strtoll
  95 function
  96 converts the string in
  97 .Fa str
  98 to a
  99 .Vt "long long"
 100 value.
 101 The
 102 .Fn strtoimax
 103 function
 104 converts the string in
 105 .Fa str
 106 to an
 107 .Vt intmax_t
 108 value.
 109 The
 110 .Fn strtoq
 111 function
 112 converts the string in
 113 .Fa str
 114 to a
 115 .Vt quad_t
 116 value.
 117 The conversion is done according to the given
 118 .Fa base ,
 119 which must be between 2 and 36 inclusive,
 120 or be the special value 0.
 121 .Pp
 122 The string may begin with an arbitrary amount of white space
 123 (as determined by
 124 .Xr isspace 3 )
 125 followed by a single optional
 126 .Ql +
 127 or
 128 .Ql -
 129 sign.
 130 If
 131 .Fa base
 132 is zero or 16,
 133 the string may then include a
 134 .Dq Li 0x
 135 prefix,
 136 and the number will be read in base 16; otherwise, a zero
 137 .Fa base
 138 is taken as 10 (decimal) unless the next character is
 139 .Ql 0 ,
 140 in which case it is taken as 8 (octal).
 141 .Pp
 142 The remainder of the string is converted to a
 143 .Vt long , "long long" , intmax_t
 144 or
 145 .Vt quad_t
 146 value in the obvious manner,
 147 stopping at the first character which is not a valid digit
 148 in the given base.
 149 (In bases above 10, the letter
 150 .Ql A
 151 in either upper or lower case
 152 represents 10,
 153 .Ql B
 154 represents 11, and so forth, with
 155 .Ql Z
 156 representing 35.)
 157 .Pp
 158 If
 159 .Fa endptr
 160 is not
 161 .Dv NULL ,
 162 .Fn strtol
 163 stores the address of the first invalid character in
 164 .Fa *endptr .
 165 If there were no digits at all, however,
 166 .Fn strtol
 167 stores the original value of
 168 .Fa str
 169 in
 170 .Fa *endptr .
 171 (Thus, if
 172 .Fa *str
 173 is not
 174 .Ql \e0
 175 but
 176 .Fa **endptr
 177 is
 178 .Ql \e0
 179 on return, the entire string was valid.)
 180 .Pp
 181 Extended locale versions of these functions are documented in
 182 .Xr strtol_l 3 .
 183 See
 184 .Xr xlocale 3
 185 for more information.
 186 .Sh RETURN VALUES
 187 The
 188 .Fn strtol ,
 189 .Fn strtoll ,
 190 .Fn strtoimax ,
 191 and
 192 .Fn strtoq
 193 functions
 194 return the result of the conversion,
 195 unless the value would underflow or overflow.
 196 If no conversion could be performed, 0 is returned and
 197 the global variable
 198 .Va errno
 199 is set to
 200 .Er EINVAL
 201 (the last feature is not portable across all platforms).
 202 If an overflow or underflow occurs,
 203 .Va errno
 204 is set to
 205 .Er ERANGE
 206 and the function return value is clamped according
 207 to the following table.
 208 .Bl -column -offset indent ".Fn strtoimax" ".Dv INTMAX_MIN" ".Dv INTMAX_MAX"
 209 .It Sy Function Ta Sy underflow Ta Sy overflow
 210 .It Fn strtol Ta Dv LONG_MIN Ta Dv LONG_MAX
 211 .It Fn strtoll Ta Dv LLONG_MIN Ta Dv LLONG_MAX
 212 .It Fn strtoimax Ta Dv INTMAX_MIN Ta Dv INTMAX_MAX
 213 .It Fn strtoq Ta Dv LLONG_MIN Ta Dv LLONG_MAX
 214 .El
 215 .Sh ERRORS
 216 .Bl -tag -width Er
 217 .It Bq Er EINVAL
 218 The value of
 219 .Fa base
 220 is not supported or
 221 no conversion could be performed
 222 (the last feature is not portable across all platforms).
 223 .It Bq Er ERANGE
 224 The given string was out of range; the value converted has been clamped.
 225 .El
 226 .Sh LEGACY SYNOPSIS
 227 .Fd #include <stdlib.h>
 228 .Fd #include <limits.h>
 229 .Pp
 230 .In limits.h
 231 is necessary for the
 232 .Fn strtol
 233 and
 234 .Fn strtoll
 235 functions.
 236 .Sh SEE ALSO
 237 .Xr atof 3 ,
 238 .Xr atoi 3 ,
 239 .Xr atol 3 ,
 240 .Xr strtod 3 ,
 241 .Xr strtol_l 3 ,
 242 .Xr strtoul 3 ,
 243 .Xr wcstol 3 ,
 244 .Xr compat 5
 245 .Sh STANDARDS
 246 The
 247 .Fn strtol
 248 function
 249 conforms to
 250 .St -isoC .
 251 The
 252 .Fn strtoll
 253 and
 254 .Fn strtoimax
 255 functions
 256 conform to
 257 .St -isoC-99 .
 258 The
 259 .Bx
 260 .Fn strtoq
 261 function is deprecated.