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

.\" Copyright (c) 1990, 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Chris Torek and the American National Standards Committee X3,
.\" on Information Processing Systems.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)strtoul.3	5.3 (Berkeley) 6/29/91
.\"
.Dd June 29, 1991
.Dt STRTOUL 3
.Os
.Sh NAME
.Nm strtoul
.Nd convert a string to an unsigned long integer
.Sh SYNOPSIS
.Fd #include <stdlib.h>
.Fd #include <limits.h>
.Fn strtoul "const char *nptr" "char **endptr" "int base"
.Sh DESCRIPTION
The
.Fn strtoul
function
converts the string in
.Fa nptr
to an
.Em unsigned long
value according to the given
.Fa 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
.Xr isspace 3 )
followed by a single optional
.Ql +
or
.Ql -
sign.
If
.Fa base
is zero or 16,
the string may then include a
.Ql 0x
prefix,
and the number will be read in base 16; otherwise, a zero
.Fa base
is taken as 10 (decimal) unless the next character is
.Ql 0 ,
in which case it is taken as 8 (octal).
.Pp
The remainder of the string is converted to an
.Em 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
.Ql A
in either upper or lower case
represents 10,
.Ql B
represents 11, and so forth, with
.Ql Z
representing 35.)
.Pp
If
.Fa endptr
is non nil,
.Fn strtoul
stores the address of the first invalid character in
.Fa *endptr .
If there were no digits at all, however,
.Fn strtoul
stores the original value of
.Fa nptr
in
.Fa *endptr .
(Thus, if
.Fa *nptr
is not
.Ql \e0
but
.Fa **endptr
is
.Ql \e0
on return, the entire string was valid.)
.Sh RETURN VALUES
The
.Fn strtoul
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,
.Fn strtoul
returns
.Dv ULONG_MAX
and sets the global variable
.Va errno
to
.Er ERANGE .
.Sh ERRORS
.Bl -tag -width [ERANGE]
.It Bq Er ERANGE
The given string was out of range; the value converted has been clamped.
.El
.Sh SEE ALSO
.Xr strtol 3
.Sh STANDARDS
The
.Fn strtoul
function
conforms to
.St -ansiC .
.Sh BUGS
Ignores the current locale.
Commit	Line	Data
15637ed4 RG	1	.\" Copyright (c) 1990, 1991 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 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	.\" @(#)strtoul.3 5.3 (Berkeley) 6/29/91
	37	.\"
	38	.Dd June 29, 1991
	39	.Dt STRTOUL 3
	40	.Os
	41	.Sh NAME
	42	.Nm strtoul
	43	.Nd convert a string to an unsigned long integer
	44	.Sh SYNOPSIS
	45	.Fd #include <stdlib.h>
	46	.Fd #include <limits.h>
	47	.Fn strtoul "const char nptr" "char *endptr" "int base"
	48	.Sh DESCRIPTION
	49	The
	50	.Fn strtoul
	51	function
	52	converts the string in
	53	.Fa nptr
	54	to an
	55	.Em unsigned long
	56	value according to the given
	57	.Fa base ,
	58	which must be between 2 and 36 inclusive,
	59	or be the special value 0.
	60	.Pp
	61	The string may begin with an arbitrary amount of white space
	62	(as determined by
	63	.Xr isspace 3 )
	64	followed by a single optional
65	.Ql +
66	or
67	.Ql -
68	sign.
69	If
70	.Fa base
71	is zero or 16,
72	the string may then include a
73	.Ql 0x
74	prefix,
75	and the number will be read in base 16; otherwise, a zero
76	.Fa base
77	is taken as 10 (decimal) unless the next character is
78	.Ql 0 ,
79	in which case it is taken as 8 (octal).
80	.Pp
81	The remainder of the string is converted to an
82	.Em unsigned long
83	value in the obvious manner,
84	stopping at the end of the string
85	or at the first character that does not produce a valid digit
86	in the given base.
87	(In bases above 10, the letter
88	.Ql A
89	in either upper or lower case
90	represents 10,
91	.Ql B
92	represents 11, and so forth, with
93	.Ql Z
94	representing 35.)
95	.Pp
96	If
97	.Fa endptr
98	is non nil,
99	.Fn strtoul
100	stores the address of the first invalid character in
101	.Fa *endptr .
102	If there were no digits at all, however,
103	.Fn strtoul
104	stores the original value of
105	.Fa nptr
106	in
107	.Fa *endptr .
108	(Thus, if
109	.Fa *nptr
110	is not
111	.Ql \e0
112	but
113	.Fa **endptr
114	is
115	.Ql \e0
116	on return, the entire string was valid.)
117	.Sh RETURN VALUES
118	The
119	.Fn strtoul
120	function
121	returns either the result of the conversion
122	or, if there was a leading minus sign,
123	the negation of the result of the conversion,
124	unless the original (non-negated) value would overflow;
125	in the latter case,
126	.Fn strtoul
127	returns
128	.Dv ULONG_MAX
129	and sets the global variable
130	.Va errno
131	to
132	.Er ERANGE .
133	.Sh ERRORS
134	.Bl -tag -width [ERANGE]
135	.It Bq Er ERANGE
136	The given string was out of range; the value converted has been clamped.
137	.El
138	.Sh SEE ALSO
139	.Xr strtol 3
140	.Sh STANDARDS
141	The
142	.Fn strtoul
143	function
144	conforms to
145	.St -ansiC .
146	.Sh BUGS
147	Ignores the current locale.