mirror of https://github.com/mkerrisk/man-pages
66 lines
2.1 KiB
Plaintext
66 lines
2.1 KiB
Plaintext
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
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.TH "ISDIGIT" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
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.\" isdigit
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.SH NAME
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isdigit \- test for a decimal digit
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.SH SYNOPSIS
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.LP
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\fB#include <ctype.h>
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.br
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.sp
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int isdigit(int\fP \fIc\fP\fB);
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.br
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\fP
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.SH DESCRIPTION
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.LP
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The \fIisdigit\fP() function shall test whether \fIc\fP is a character
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of class \fBdigit\fP in the program's current locale;
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see the Base Definitions volume of IEEE\ Std\ 1003.1-2001, Chapter
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7, Locale.
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.LP
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The \fIc\fP argument is an \fBint\fP, the value of which the application
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shall ensure is a character representable as an
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\fBunsigned char\fP or equal to the value of the macro EOF. If the
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argument has any other value, the behavior is undefined.
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.SH RETURN VALUE
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.LP
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The \fIisdigit\fP() function shall return non-zero if \fIc\fP is a
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decimal digit; otherwise, it shall return 0.
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.SH ERRORS
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.LP
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No errors are defined.
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.LP
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\fIThe following sections are informative.\fP
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.SH EXAMPLES
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.LP
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None.
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.SH APPLICATION USAGE
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.LP
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To ensure applications portability, especially across natural languages,
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only this function and those listed in the SEE ALSO
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section should be used for character classification.
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.SH RATIONALE
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.LP
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None.
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.SH FUTURE DIRECTIONS
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.LP
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None.
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.SH SEE ALSO
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.LP
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\fIisalnum\fP() , \fIisalpha\fP() , \fIiscntrl\fP() , \fIisgraph\fP()
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, \fIislower\fP() ,
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\fIisprint\fP() , \fIispunct\fP() , \fIisspace\fP() , \fIisupper\fP()
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, \fIisxdigit\fP() ,
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the Base Definitions volume of IEEE\ Std\ 1003.1-2001, Chapter 7,
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Locale, \fI<ctype.h>\fP
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.SH COPYRIGHT
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Portions of this text are reprinted and reproduced in electronic form
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from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
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-- Portable Operating System Interface (POSIX), The Open Group Base
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Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
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Electrical and Electronics Engineers, Inc and The Open Group. In the
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event of any discrepancy between this version and the original IEEE and
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The Open Group Standard, the original IEEE and The Open Group Standard
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is the referee document. The original Standard can be obtained online at
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http://www.opengroup.org/unix/online.html .
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