| .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
| .\" |
| .\" Permission is granted to make and distribute verbatim copies of this |
| .\" manual provided the copyright notice and this permission notice are |
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| .\" Permission is granted to copy and distribute modified versions of this |
| .\" manual under the conditions for verbatim copying, provided that the |
| .\" entire resulting derived work is distributed under the terms of a |
| .\" permission notice identical to this one. |
| .\" |
| .\" Since the Linux kernel and libraries are constantly changing, this |
| .\" manual page may be incorrect or out-of-date. The author(s) assume no |
| .\" responsibility for errors or omissions, or for damages resulting from |
| .\" the use of the information contained herein. The author(s) may not |
| .\" have taken the same level of care in the production of this manual, |
| .\" which is licensed free of charge, as they might when working |
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| .\" |
| .\" Formatted or processed versions of this manual, if unaccompanied by |
| .\" the source, must acknowledge the copyright and authors of this work. |
| .\" |
| .\" References consulted: |
| .\" Linux libc source code |
| .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) |
| .\" 386BSD man pages |
| .\" Modified Sun Jul 25 10:54:03 1993 by Rik Faith (faith@cs.unc.edu) |
| .\" Fixed typo, aeb, 950823 |
| .\" 2002-02-22, joey, mihtjel: Added strtoull() |
| .\" |
| .TH STRTOUL 3 2002-05-30 "GNU" "Linux Programmer's Manual" |
| .SH NAME |
| strtoul, strtoull, strtouq \- convert a string to an unsigned long integer |
| .SH SYNOPSIS |
| .nf |
| .B #include <stdlib.h> |
| .sp |
| .BI "unsigned long int" |
| .BI "strtoul(const char *" nptr ", char **" endptr ", int " base ); |
| .sp |
| .BI "unsigned long long int" |
| .BI "strtoull(const char *" nptr ", char **" endptr ", int " base ); |
| .fi |
| .SH DESCRIPTION |
| The \fBstrtoul\fP() function converts the initial part of the string |
| in \fInptr\fP to an unsigned long integer value according to the |
| given \fIbase\fP, which must be between 2 and 36 inclusive, or be |
| the special value 0. |
| .PP |
| The string may begin with an arbitrary amount of white space (as |
| determined by |
| .BR isspace (3)) |
| followed by a single optional `+' or `\-' |
| sign. If \fIbase\fP is zero or 16, the string may then include a |
| `0x' prefix, and the number will be read in base 16; otherwise, a |
| zero \fIbase\fP is taken as 10 (decimal) unless the next character |
| is `0', in which case it is taken as 8 (octal). |
| .PP |
| The remainder of the string is converted to an unsigned long int value |
| in the obvious manner, stopping at the first character which is not a |
| valid digit in the given base. (In bases above 10, the letter `A' in |
| either upper or lower case represents 10, `B' represents 11, and so |
| forth, with `Z' representing 35.) |
| .PP |
| If \fIendptr\fP is not NULL, \fBstrtoul\fP() stores the address of the |
| first invalid character in \fI*endptr\fP. If there were no digits at |
| all, \fBstrtoul\fP() stores the original value of \fInptr\fP in |
| \fI*endptr\fP (and returns 0). |
| In particular, if \fI*nptr\fP is not `\\0' but \fI**endptr\fP |
| is `\\0' on return, the entire string is valid. |
| .PP |
| The |
| .BR strtoull () |
| function works just like the |
| .BR strtoul () |
| function but returns an unsigned long long integer value. |
| .SH "RETURN VALUE" |
| The \fBstrtoul\fP() function returns either the result of the conversion |
| or, if there was a leading minus sign, the negation of the result of the |
| conversion, unless the original (non-negated) value would overflow; in |
| the latter case, \fBstrtoul\fP() returns ULONG_MAX and sets the global |
| variable \fIerrno\fP to ERANGE. |
| Precisely the same holds for |
| .BR strtoull () |
| (with ULLONG_MAX instead of ULONG_MAX). |
| .SH ERRORS |
| .TP |
| .B EINVAL |
| (not in C99) |
| The given |
| .I base |
| contains an unsupported value. |
| .TP |
| .B ERANGE |
| The resulting value was out of range. |
| .LP |
| The implementation may also set \fIerrno\fP to \fBEINVAL\fP in case |
| no conversion was performed (no digits seen, and 0 returned). |
| .SH NOTES |
| In locales other than the "C" locale, also other strings may be accepted. |
| (For example, the thousands separator of the current locale may be |
| supported.) |
| .LP |
| BSD also has |
| .sp |
| .in +4n |
| .nf |
| .BI "u_quad_t" |
| .BI "strtouq(const char *" nptr ", char **" endptr ", int base" ); |
| .sp |
| .in -4n |
| .fi |
| with completely analogous definition. |
| Depending on the wordsize of the current architecture, this |
| may be equivalent to |
| .BR strtoull () |
| or to |
| .BR strtoul (). |
| .SH "CONFORMING TO" |
| .BR strtoul () |
| conforms to SVID 3, 4.3BSD, ISO 9899 (C99) and POSIX, and |
| .BR strtoull () |
| to ISO 9899 (C99) and POSIX 1003.1-2001. |
| .SH "SEE ALSO" |
| .BR atof (3), |
| .BR atoi (3), |
| .BR atol (3), |
| .BR strtod (3), |
| .BR strtol (3) |