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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 | .\" |
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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14 | .\" manual page may be incorrect or out-of-date.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 | .\" | |
f81c6cc6 | 33 | .TH STRTOUL 3 2011-09-15 "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> | |
39 | .sp | |
62218dc0 MK |
40 | .BI "unsigned long int strtoul(const char *" nptr ", char **" endptr \ |
41 | ", int " base ); | |
fea681da | 42 | .sp |
62218dc0 MK |
43 | .BI "unsigned long long int strtoull(const char *" nptr ", char **" endptr , |
44 | .BI " int " base ); | |
fea681da | 45 | .fi |
cc4615cc MK |
46 | .sp |
47 | .in -4n | |
48 | Feature Test Macro Requirements for glibc (see | |
49 | .BR feature_test_macros (7)): | |
50 | .in | |
51 | .sp | |
52 | .ad l | |
53 | .BR strtoull (): | |
e0a98111 | 54 | .RS 4 |
98dbe7af | 55 | XOPEN_SOURCE\ >=\ 600 || _BSD_SOURCE || _SVID_SOURCE || _ISOC99_SOURCE || |
6c3f0228 | 56 | _POSIX_C_SOURCE\ >=\ 200112L; |
e0a98111 MK |
57 | .br |
58 | or | |
cc4615cc | 59 | .I cc\ -std=c99 |
e0a98111 MK |
60 | .RE |
61 | .ad | |
fea681da | 62 | .SH DESCRIPTION |
60a90ecd MK |
63 | The |
64 | .BR strtoul () | |
65 | function converts the initial part of the string | |
46d8df8e MK |
66 | in |
67 | .I nptr | |
68 | to an | |
d9a10d9d MK |
69 | .I "unsigned long int" |
70 | value according to the | |
46d8df8e MK |
71 | given |
72 | .IR base , | |
73 | which must be between 2 and 36 inclusive, or be | |
fea681da MK |
74 | the special value 0. |
75 | .PP | |
3f266a43 | 76 | The string may begin with an arbitrary amount of white space (as |
fea681da MK |
77 | determined by |
78 | .BR isspace (3)) | |
f81fb444 | 79 | followed by a single optional \(aq+\(aq or \(aq\-\(aq |
c13182ef | 80 | sign. |
46d8df8e MK |
81 | If |
82 | .I base | |
83 | is zero or 16, the string may then include a | |
928410b4 | 84 | "0x" prefix, and the number will be read in base 16; otherwise, a |
46d8df8e MK |
85 | zero |
86 | .I base | |
87 | is taken as 10 (decimal) unless the next character | |
f81fb444 | 88 | is \(aq0\(aq, in which case it is taken as 8 (octal). |
fea681da | 89 | .PP |
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90 | The remainder of the string is converted to an |
91 | .I "unsigned long int" | |
92 | value in the obvious manner, | |
93 | stopping at the first character which is not a | |
c13182ef | 94 | valid digit in the given base. |
f81fb444 MK |
95 | (In bases above 10, the letter \(aqA\(aq in |
96 | either upper or lower case represents 10, \(aqB\(aq represents 11, and so | |
97 | forth, with \(aqZ\(aq representing 35.) | |
fea681da | 98 | .PP |
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99 | If |
100 | .I endptr | |
101 | is not NULL, | |
60a90ecd MK |
102 | .BR strtoul () |
103 | stores the address of the | |
46d8df8e MK |
104 | first invalid character in |
105 | .IR *endptr . | |
c13182ef | 106 | If there were no digits at |
60a90ecd MK |
107 | all, |
108 | .BR strtoul () | |
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109 | stores the original value of |
110 | .I nptr | |
111 | in | |
112 | .I *endptr | |
113 | (and returns 0). | |
114 | In particular, if | |
115 | .I *nptr | |
116 | is not \(aq\\0\(aq but | |
117 | .I **endptr | |
f81fb444 | 118 | is \(aq\\0\(aq on return, the entire string is valid. |
fea681da MK |
119 | .PP |
120 | The | |
63aa9df0 | 121 | .BR strtoull () |
fea681da | 122 | function works just like the |
63aa9df0 | 123 | .BR strtoul () |
d9a10d9d MK |
124 | function but returns an |
125 | .I "unsigned long long int" | |
126 | value. | |
47297adb | 127 | .SH RETURN VALUE |
60a90ecd MK |
128 | The |
129 | .BR strtoul () | |
130 | function returns either the result of the conversion | |
fea681da | 131 | or, if there was a leading minus sign, the negation of the result of the |
c13182ef | 132 | conversion represented as an unsigned value, |
74cee559 | 133 | unless the original (nonnegated) value would overflow; in |
60a90ecd MK |
134 | the latter case, |
135 | .BR strtoul () | |
a9b4ebbc MK |
136 | returns |
137 | .B ULONG_MAX | |
46d8df8e MK |
138 | and sets |
139 | .I errno | |
140 | to | |
a9b4ebbc | 141 | .BR ERANGE . |
fea681da | 142 | Precisely the same holds for |
63aa9df0 | 143 | .BR strtoull () |
a9b4ebbc MK |
144 | (with |
145 | .B ULLONG_MAX | |
146 | instead of | |
147 | .BR ULONG_MAX ). | |
fea681da MK |
148 | .SH ERRORS |
149 | .TP | |
150 | .B EINVAL | |
151 | (not in C99) | |
152 | The given | |
153 | .I base | |
154 | contains an unsupported value. | |
155 | .TP | |
156 | .B ERANGE | |
157 | The resulting value was out of range. | |
158 | .LP | |
46d8df8e | 159 | The implementation may also set |
51700fd7 | 160 | .IR errno |
46d8df8e MK |
161 | to |
162 | .B EINVAL | |
163 | in case | |
fea681da | 164 | no conversion was performed (no digits seen, and 0 returned). |
47297adb | 165 | .SH CONFORMING TO |
2b2581ee MK |
166 | .BR strtoul () |
167 | conforms to SVr4, C89, C99 and POSIX-2001, and | |
168 | .BR strtoull () | |
169 | to C99 and POSIX.1-2001. | |
fea681da | 170 | .SH NOTES |
c13182ef | 171 | Since |
fefe023e | 172 | .BR strtoul () |
a9b4ebbc | 173 | can legitimately return 0 or |
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174 | .B ULONG_MAX |
175 | .RB ( ULLONG_MAX | |
a9b4ebbc | 176 | for |
fefe023e MK |
177 | .BR strtoull ()) |
178 | on both success and failure, the calling program should set | |
179 | .I errno | |
c13182ef | 180 | to 0 before the call, |
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181 | and then determine if an error occurred by checking whether |
182 | .I errno | |
c7094399 | 183 | has a nonzero value after the call. |
fefe023e | 184 | |
190c7abe | 185 | In locales other than the "C" locale, other strings may be accepted. |
fea681da MK |
186 | (For example, the thousands separator of the current locale may be |
187 | supported.) | |
188 | .LP | |
189 | BSD also has | |
190 | .sp | |
191 | .in +4n | |
192 | .nf | |
37370164 | 193 | .BI "u_quad_t strtouq(const char *" nptr ", char **" endptr ", int " base ); |
fea681da MK |
194 | .sp |
195 | .in -4n | |
196 | .fi | |
197 | with completely analogous definition. | |
198 | Depending on the wordsize of the current architecture, this | |
199 | may be equivalent to | |
63aa9df0 | 200 | .BR strtoull () |
fea681da | 201 | or to |
63aa9df0 | 202 | .BR strtoul (). |
190c7abe MK |
203 | |
204 | Negative values are considered valid input and are | |
d9a10d9d MK |
205 | silently converted to the equivalent |
206 | .I "unsigned long int" | |
207 | value. | |
5a1cae6b MK |
208 | .SH EXAMPLE |
209 | See the example on the | |
210 | .BR strtol (3) | |
c13182ef | 211 | manual page; |
5a1cae6b | 212 | the use of the functions described in this manual page is similar. |
47297adb | 213 | .SH SEE ALSO |
fea681da MK |
214 | .BR atof (3), |
215 | .BR atoi (3), | |
216 | .BR atol (3), | |
217 | .BR strtod (3), | |
218 | .BR strtol (3) |