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1 | .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
2 | .\" | |
93015253 | 3 | .\" %%%LICENSE_START(VERBATIM) |
fea681da MK |
4 | .\" Permission is granted to make and distribute verbatim copies of this |
5 | .\" manual provided the copyright notice and this permission notice are | |
6 | .\" preserved on all copies. | |
7 | .\" | |
8 | .\" Permission is granted to copy and distribute modified versions of this | |
9 | .\" manual under the conditions for verbatim copying, provided that the | |
10 | .\" entire resulting derived work is distributed under the terms of a | |
11 | .\" permission notice identical to this one. | |
c13182ef | 12 | .\" |
fea681da MK |
13 | .\" Since the Linux kernel and libraries are constantly changing, this |
14 | .\" manual page may be incorrect or out-of-date. The author(s) assume no | |
15 | .\" responsibility for errors or omissions, or for damages resulting from | |
16 | .\" the use of the information contained herein. The author(s) may not | |
17 | .\" have taken the same level of care in the production of this manual, | |
18 | .\" which is licensed free of charge, as they might when working | |
19 | .\" professionally. | |
c13182ef | 20 | .\" |
fea681da MK |
21 | .\" Formatted or processed versions of this manual, if unaccompanied by |
22 | .\" the source, must acknowledge the copyright and authors of this work. | |
4b72fb64 | 23 | .\" %%%LICENSE_END |
fea681da MK |
24 | .\" |
25 | .\" References consulted: | |
26 | .\" Linux libc source code | |
27 | .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) | |
28 | .\" 386BSD man pages | |
29 | .\" Modified Sun Jul 25 10:54:03 1993 by Rik Faith (faith@cs.unc.edu) | |
30 | .\" Fixed typo, aeb, 950823 | |
31 | .\" 2002-02-22, joey, mihtjel: Added strtoull() | |
32 | .\" | |
4b8c67d9 | 33 | .TH STRTOUL 3 2017-09-15 "GNU" "Linux Programmer's Manual" |
fea681da MK |
34 | .SH NAME |
35 | strtoul, strtoull, strtouq \- convert a string to an unsigned long integer | |
36 | .SH SYNOPSIS | |
37 | .nf | |
38 | .B #include <stdlib.h> | |
68e4db0a | 39 | .PP |
62218dc0 MK |
40 | .BI "unsigned long int strtoul(const char *" nptr ", char **" endptr \ |
41 | ", int " base ); | |
68e4db0a | 42 | .PP |
62218dc0 MK |
43 | .BI "unsigned long long int strtoull(const char *" nptr ", char **" endptr , |
44 | .BI " int " base ); | |
fea681da | 45 | .fi |
68e4db0a | 46 | .PP |
cc4615cc MK |
47 | .in -4n |
48 | Feature Test Macro Requirements for glibc (see | |
49 | .BR feature_test_macros (7)): | |
50 | .in | |
68e4db0a | 51 | .PP |
cc4615cc MK |
52 | .ad l |
53 | .BR strtoull (): | |
e0a98111 | 54 | .RS 4 |
2b1b0424 MK |
55 | _ISOC99_SOURCE || |
56 | || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE | |
e0a98111 MK |
57 | .RE |
58 | .ad | |
fea681da | 59 | .SH DESCRIPTION |
60a90ecd MK |
60 | The |
61 | .BR strtoul () | |
62 | function converts the initial part of the string | |
46d8df8e MK |
63 | in |
64 | .I nptr | |
65 | to an | |
d9a10d9d MK |
66 | .I "unsigned long int" |
67 | value according to the | |
46d8df8e MK |
68 | given |
69 | .IR base , | |
70 | which must be between 2 and 36 inclusive, or be | |
fea681da MK |
71 | the special value 0. |
72 | .PP | |
3f266a43 | 73 | The string may begin with an arbitrary amount of white space (as |
fea681da MK |
74 | determined by |
75 | .BR isspace (3)) | |
f81fb444 | 76 | followed by a single optional \(aq+\(aq or \(aq\-\(aq |
c13182ef | 77 | sign. |
46d8df8e MK |
78 | If |
79 | .I base | |
80 | is zero or 16, the string may then include a | |
928410b4 | 81 | "0x" prefix, and the number will be read in base 16; otherwise, a |
46d8df8e MK |
82 | zero |
83 | .I base | |
84 | is taken as 10 (decimal) unless the next character | |
f81fb444 | 85 | is \(aq0\(aq, in which case it is taken as 8 (octal). |
fea681da | 86 | .PP |
d9a10d9d MK |
87 | The remainder of the string is converted to an |
88 | .I "unsigned long int" | |
89 | value in the obvious manner, | |
90 | stopping at the first character which is not a | |
c13182ef | 91 | valid digit in the given base. |
f81fb444 | 92 | (In bases above 10, the letter \(aqA\(aq in |
efaef3da | 93 | either uppercase or lowercase represents 10, \(aqB\(aq represents 11, and so |
f81fb444 | 94 | forth, with \(aqZ\(aq representing 35.) |
fea681da | 95 | .PP |
46d8df8e MK |
96 | If |
97 | .I endptr | |
98 | is not NULL, | |
60a90ecd MK |
99 | .BR strtoul () |
100 | stores the address of the | |
46d8df8e MK |
101 | first invalid character in |
102 | .IR *endptr . | |
c13182ef | 103 | If there were no digits at |
60a90ecd MK |
104 | all, |
105 | .BR strtoul () | |
46d8df8e MK |
106 | stores the original value of |
107 | .I nptr | |
108 | in | |
109 | .I *endptr | |
110 | (and returns 0). | |
111 | In particular, if | |
112 | .I *nptr | |
113 | is not \(aq\\0\(aq but | |
114 | .I **endptr | |
f81fb444 | 115 | is \(aq\\0\(aq on return, the entire string is valid. |
fea681da MK |
116 | .PP |
117 | The | |
63aa9df0 | 118 | .BR strtoull () |
fea681da | 119 | function works just like the |
63aa9df0 | 120 | .BR strtoul () |
d9a10d9d MK |
121 | function but returns an |
122 | .I "unsigned long long int" | |
123 | value. | |
47297adb | 124 | .SH RETURN VALUE |
60a90ecd MK |
125 | The |
126 | .BR strtoul () | |
127 | function returns either the result of the conversion | |
fea681da | 128 | or, if there was a leading minus sign, the negation of the result of the |
c13182ef | 129 | conversion represented as an unsigned value, |
74cee559 | 130 | unless the original (nonnegated) value would overflow; in |
60a90ecd MK |
131 | the latter case, |
132 | .BR strtoul () | |
a9b4ebbc MK |
133 | returns |
134 | .B ULONG_MAX | |
46d8df8e MK |
135 | and sets |
136 | .I errno | |
137 | to | |
a9b4ebbc | 138 | .BR ERANGE . |
fea681da | 139 | Precisely the same holds for |
63aa9df0 | 140 | .BR strtoull () |
a9b4ebbc MK |
141 | (with |
142 | .B ULLONG_MAX | |
143 | instead of | |
144 | .BR ULONG_MAX ). | |
fea681da MK |
145 | .SH ERRORS |
146 | .TP | |
147 | .B EINVAL | |
148 | (not in C99) | |
149 | The given | |
150 | .I base | |
151 | contains an unsupported value. | |
152 | .TP | |
153 | .B ERANGE | |
154 | The resulting value was out of range. | |
dd3568a1 | 155 | .PP |
46d8df8e | 156 | The implementation may also set |
51700fd7 | 157 | .IR errno |
46d8df8e MK |
158 | to |
159 | .B EINVAL | |
160 | in case | |
fea681da | 161 | no conversion was performed (no digits seen, and 0 returned). |
232ea96e | 162 | .SH ATTRIBUTES |
ea7d8816 PH |
163 | For an explanation of the terms used in this section, see |
164 | .BR attributes (7). | |
165 | .TS | |
166 | allbox; | |
167 | lbw32 lb lb | |
168 | l l l. | |
169 | Interface Attribute Value | |
170 | T{ | |
232ea96e PH |
171 | .BR strtoul (), |
172 | .BR strtoull (), | |
232ea96e | 173 | .BR strtouq () |
ea7d8816 PH |
174 | T} Thread safety MT-Safe locale |
175 | .TE | |
47297adb | 176 | .SH CONFORMING TO |
a1863f84 MK |
177 | .BR strtoul (): |
178 | POSIX.1-2001, POSIX.1-2008, C89, C99 SVr4. | |
847e0d88 | 179 | .PP |
a1863f84 MK |
180 | .BR strtoull (): |
181 | POSIX.1-2001, POSIX.1-2008, C99. | |
fea681da | 182 | .SH NOTES |
c13182ef | 183 | Since |
fefe023e | 184 | .BR strtoul () |
a9b4ebbc | 185 | can legitimately return 0 or |
9c60f8f4 MK |
186 | .B ULONG_MAX |
187 | .RB ( ULLONG_MAX | |
a9b4ebbc | 188 | for |
fefe023e MK |
189 | .BR strtoull ()) |
190 | on both success and failure, the calling program should set | |
191 | .I errno | |
c13182ef | 192 | to 0 before the call, |
fefe023e MK |
193 | and then determine if an error occurred by checking whether |
194 | .I errno | |
c7094399 | 195 | has a nonzero value after the call. |
847e0d88 | 196 | .PP |
190c7abe | 197 | In locales other than the "C" locale, other strings may be accepted. |
fea681da MK |
198 | (For example, the thousands separator of the current locale may be |
199 | supported.) | |
dd3568a1 | 200 | .PP |
fea681da | 201 | BSD also has |
bdd915e2 | 202 | .PP |
fea681da | 203 | .in +4n |
bdd915e2 | 204 | .EX |
37370164 | 205 | .BI "u_quad_t strtouq(const char *" nptr ", char **" endptr ", int " base ); |
bdd915e2 MK |
206 | .EE |
207 | .in | |
208 | .PP | |
fea681da MK |
209 | with completely analogous definition. |
210 | Depending on the wordsize of the current architecture, this | |
211 | may be equivalent to | |
63aa9df0 | 212 | .BR strtoull () |
fea681da | 213 | or to |
63aa9df0 | 214 | .BR strtoul (). |
847e0d88 | 215 | .PP |
190c7abe | 216 | Negative values are considered valid input and are |
d9a10d9d MK |
217 | silently converted to the equivalent |
218 | .I "unsigned long int" | |
219 | value. | |
5a1cae6b MK |
220 | .SH EXAMPLE |
221 | See the example on the | |
222 | .BR strtol (3) | |
c13182ef | 223 | manual page; |
5a1cae6b | 224 | the use of the functions described in this manual page is similar. |
47297adb | 225 | .SH SEE ALSO |
c5453914 | 226 | .BR a64l (3), |
fea681da MK |
227 | .BR atof (3), |
228 | .BR atoi (3), | |
229 | .BR atol (3), | |
230 | .BR strtod (3), | |
231 | .BR strtol (3) |