[unix-history] / usr / src / lib / libc / stdlib / strtoul.3

.\" Copyright (c) 1990 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Chris Torek.
.\"
.\" Redistribution and use in source and binary forms are permitted
.\" provided that: (1) source distributions retain this entire copyright
.\" notice and comment, and (2) distributions including binaries display
.\" the following acknowledgement:  ``This product includes software
.\" developed by the University of California, Berkeley and its contributors''
.\" in the documentation or other materials provided with the distribution
.\" and in all advertising materials mentioning features or use of this
.\" software. Neither the name of the University nor the names of its
.\" contributors may be used to endorse or promote products derived
.\" from this software without specific prior written permission.
.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
.\"
.\"	@(#)strtoul.3	5.1 (Berkeley) 5/15/90
.\"
.TH STRTOUL 3 "May 15, 1990"
.UC 7
.SH NAME
strtoul \- convert a string to an unsigned long integer
.SH SYNOPSIS
.B #include <stdlib.h>
.br
.B #include <limits.h>
.PP
.B "unsigned long strtoul(char *nptr, char **endptr, int base);
.SH DESCRIPTION
.B Strtoul
converts the string in
.I nptr
to an
.B "unsigned long"
value according to the given
.IR base ,
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 ;
see
.IR ctype (3)),
followed by a single optional `+' or `-' sign.
If
.I base
is zero or 16,
the string may then include a `0x' prefix,
and the number will be read in base 16; otherwise, a zero
.I base
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
.B "unsigned long"
value in the obvious manner,
stopping at the end of the string
or at the first character that does not produce 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
.I endptr
is non nil,
.B strtoul
stores the address of the first invalid character in
.IR *endptr .
If there were no digits at all, however,
.B strtoul
stores the original value of
.I nptr
in
.IR *endptr .
(Thus, if
.I *nptr
is not '\e0' but
.IR **endptr
is '\e0' on return, the entire string was valid.)
.SH RETURN VALUE
.B Strtoul
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,
.B strtoul
returns
.B ULONG_MAX
and sets
.B errno
to
.BR ERANGE .
.SH ERRORS
.TP
[ERANGE]
The given string was out of range; the value converted has been clamped.
.SH SEE ALSO
strtol(3)
.SH STANDARDS
.B Strtoul
conforms to ANSI X3.159-1989 (``ANSI C'').
.SH BUGS
Ignores the current locale.
Commit	Line	Data
375c4de4 KB	1	.\" Copyright (c) 1990 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.
	6	.\"
1c15e888 C	7	.\" Redistribution and use in source and binary forms are permitted
	8	.\" provided that: (1) source distributions retain this entire copyright
	9	.\" notice and comment, and (2) distributions including binaries display
	10	.\" the following acknowledgement: ``This product includes software
	11	.\" developed by the University of California, Berkeley and its contributors''
	12	.\" in the documentation or other materials provided with the distribution
	13	.\" and in all advertising materials mentioning features or use of this
	14	.\" software. Neither the name of the University nor the names of its
	15	.\" contributors may be used to endorse or promote products derived
	16	.\" from this software without specific prior written permission.
	17	.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
	18	.\" IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
	19	.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
375c4de4	20	.\"
1c15e888	21	.\" @(#)strtoul.3 5.1 (Berkeley) 5/15/90
375c4de4	22	.\"
1c15e888	23	.TH STRTOUL 3 "May 15, 1990"
375c4de4 KB	24	.UC 7
	25	.SH NAME
	26	strtoul \- convert a string to an unsigned long integer
	27	.SH SYNOPSIS
	28	.B #include <stdlib.h>
	29	.br
	30	.B #include <limits.h>
	31	.PP
	32	.B "unsigned long strtoul(char nptr, char *endptr, int base);
	33	.SH DESCRIPTION
	34	.B Strtoul
	35	converts the string in
	36	.I nptr
	37	to an
	38	.B "unsigned long"
	39	value according to the given
	40	.IR base ,
	41	which must be between 2 and 36 inclusive,
	42	or be the special value 0.
	43	.PP
	44	The string may begin with an arbitrary amount of white space
	45	(as determined by
	46	.BR isspace ;
	47	see
	48	.IR ctype (3)),
	49	followed by a single optional `+' or `-' sign.
	50	If
	51	.I base
	52	is zero or 16,
	53	the string may then include a `0x' prefix,
	54	and the number will be read in base 16; otherwise, a zero
	55	.I base
	56	is taken as 10 (decimal) unless the next character is `0',
	57	in which case it is taken as 8 (octal).
	58	.PP
	59	The remainder of the string is converted to an
	60	.B "unsigned long"
	61	value in the obvious manner,
	62	stopping at the end of the string
	63	or at the first character that does not produce a valid digit
	64	in the given base.
	65	(In bases above 10, the letter `A' in either upper or lower case
	66	represents 10, `B' represents 11, and so forth, with `Z' representing 35.)
	67	.PP
	68	If
	69	.I endptr
	70	is non nil,
	71	.B strtoul
	72	stores the address of the first invalid character in
	73	.IR *endptr .
	74	If there were no digits at all, however,
	75	.B strtoul
	76	stores the original value of
	77	.I nptr
	78	in
	79	.IR *endptr .
	80	(Thus, if
	81	.I *nptr
	82	is not '\e0' but
	83	.IR **endptr
	84	is '\e0' on return, the entire string was valid.)
	85	.SH RETURN VALUE
	86	.B Strtoul
	87	returns either the result of the conversion
88	or, if there was a leading minus sign,
89	the negation of the result of the conversion,
90	unless the original (non-negated) value would overflow;
91	in the latter case,
92	.B strtoul
93	returns
94	.B ULONG_MAX
95	and sets
96	.B errno
97	to
98	.BR ERANGE .
99	.SH ERRORS
100	.TP
101	[ERANGE]
102	The given string was out of range; the value converted has been clamped.
103	.SH SEE ALSO
104	strtol(3)
105	.SH STANDARDS
106	.B Strtoul
107	conforms to ANSI X3.159-1989 (``ANSI C'').
108	.SH BUGS
109	Ignores the current locale.