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diff --git a/man3/isalpha.3 b/man3/isalpha.3 new file mode 100644 index 0000000..cf0d54a --- /dev/null +++ b/man3/isalpha.3 @@ -0,0 +1,406 @@ +'\" t +.\" Copyright (c) 1993 by Thomas Koenig (ig25@rz.uni-karlsruhe.de) +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.\" Modified Sat Jul 24 19:10:00 1993 by Rik Faith (faith@cs.unc.edu) +.\" Modified Sun Aug 21 17:51:50 1994 by Rik Faith (faith@cs.unc.edu) +.\" Modified Sat Sep 2 21:52:01 1995 by Jim Van Zandt <jrv@vanzandt.mv.com> +.\" Modified Mon May 27 22:55:26 1996 by Martin Schulze (joey@linux.de) +.\" +.TH isalpha 3 2023-07-30 "Linux man-pages 6.05.01" +.SH NAME +isalnum, isalpha, isascii, isblank, iscntrl, isdigit, isgraph, islower, +isprint, ispunct, isspace, isupper, isxdigit, +isalnum_l, isalpha_l, isascii_l, isblank_l, iscntrl_l, +isdigit_l, isgraph_l, islower_l, +isprint_l, ispunct_l, isspace_l, isupper_l, isxdigit_l +\- character classification functions +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include <ctype.h> +.PP +.BI "int isalnum(int " c ); +.BI "int isalpha(int " c ); +.BI "int iscntrl(int " c ); +.BI "int isdigit(int " c ); +.BI "int isgraph(int " c ); +.BI "int islower(int " c ); +.BI "int isprint(int " c ); +.BI "int ispunct(int " c ); +.BI "int isspace(int " c ); +.BI "int isupper(int " c ); +.BI "int isxdigit(int " c ); +.PP +.BI "int isascii(int " c ); +.BI "int isblank(int " c ); +.PP +.BI "int isalnum_l(int " c ", locale_t " locale ); +.BI "int isalpha_l(int " c ", locale_t " locale ); +.BI "int isblank_l(int " c ", locale_t " locale ); +.BI "int iscntrl_l(int " c ", locale_t " locale ); +.BI "int isdigit_l(int " c ", locale_t " locale ); +.BI "int isgraph_l(int " c ", locale_t " locale ); +.BI "int islower_l(int " c ", locale_t " locale ); +.BI "int isprint_l(int " c ", locale_t " locale ); +.BI "int ispunct_l(int " c ", locale_t " locale ); +.BI "int isspace_l(int " c ", locale_t " locale ); +.BI "int isupper_l(int " c ", locale_t " locale ); +.BI "int isxdigit_l(int " c ", locale_t " locale ); +.PP +.BI "int isascii_l(int " c ", locale_t " locale ); +.fi +.PP +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.ad l +.PP +.BR isascii (): +.nf + _XOPEN_SOURCE + || /* glibc >= 2.19: */ _DEFAULT_SOURCE + || /* glibc <= 2.19: */ _SVID_SOURCE +.fi +.PP +.BR isblank (): +.nf + _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L +.fi +.PP +.BR \%salnum_l (), +.BR \%salpha_l (), +.BR \%sblank_l (), +.BR \%scntrl_l (), +.BR \%sdigit_l (), +.BR \%sgraph_l (), +.BR \%slower_l (), +.BR \%sprint_l (), +.BR \%spunct_l (), +.BR \%sspace_l (), +.BR \%supper_l (), +.BR \%sxdigit_l (): +.nf + Since glibc 2.10: + _XOPEN_SOURCE >= 700 + Before glibc 2.10: + _GNU_SOURCE +.fi +.PP +.BR isascii_l (): +.nf + Since glibc 2.10: + _XOPEN_SOURCE >= 700 && (_SVID_SOURCE || _BSD_SOURCE) + Before glibc 2.10: + _GNU_SOURCE +.fi +.ad +.SH DESCRIPTION +These functions check whether +.IR c , +which must have the value of an +.I unsigned char +or +.BR EOF , +falls into a certain character class according to the specified locale. +The functions without the +"_l" suffix perform the check based on the current locale. +.PP +The functions with the "_l" suffix perform the check +based on the locale specified by the locale object +.IR locale . +The behavior of these functions is undefined if +.I locale +is the special locale object +.B LC_GLOBAL_LOCALE +(see +.BR duplocale (3)) +or is not a valid locale object handle. +.PP +The list below explains the operation of the functions without +the "_l" suffix; +the functions with the "_l" suffix differ only in using the locale object +.I locale +instead of the current locale. +.TP +.BR isalnum () +checks for an alphanumeric character; it is equivalent to +.BI "(isalpha(" c ") || isdigit(" c "))" \fR. +.TP +.BR isalpha () +checks for an alphabetic character; in the standard \fB"C"\fP +locale, it is equivalent to +.BI "(isupper(" c ") || islower(" c "))" \fR. +In some locales, there may be additional characters for which +.BR isalpha () +is true\[em]letters which are neither uppercase nor lowercase. +.TP +.BR isascii () +checks whether \fIc\fP is a 7-bit +.I unsigned char +value that fits into +the ASCII character set. +.TP +.BR isblank () +checks for a blank character; that is, a space or a tab. +.TP +.BR iscntrl () +checks for a control character. +.TP +.BR isdigit () +checks for a digit (0 through 9). +.TP +.BR isgraph () +checks for any printable character except space. +.TP +.BR islower () +checks for a lowercase character. +.TP +.BR isprint () +checks for any printable character including space. +.TP +.BR ispunct () +checks for any printable character which is not a space or an +alphanumeric character. +.TP +.BR isspace () +checks for white-space characters. +In the +.B """C""" +and +.B """POSIX""" +locales, these are: space, form-feed +.RB ( \[aq]\ef\[aq] ), +newline +.RB ( \[aq]\en\[aq] ), +carriage return +.RB ( \[aq]\er\[aq] ), +horizontal tab +.RB ( \[aq]\et\[aq] ), +and vertical tab +.RB ( \[aq]\ev\[aq] ). +.TP +.BR isupper () +checks for an uppercase letter. +.TP +.BR isxdigit () +checks for hexadecimal digits, that is, one of +.br +.BR "0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F" . +.SH RETURN VALUE +The values returned are nonzero if the character +.I c +falls into the tested class, and zero if not. +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR isalnum (), +.BR isalpha (), +.BR isascii (), +.BR isblank (), +.BR iscntrl (), +.BR isdigit (), +.BR isgraph (), +.BR islower (), +.BR isprint (), +.BR ispunct (), +.BR isspace (), +.BR isupper (), +.BR isxdigit () +T} Thread safety MT-Safe +.TE +.sp 1 +.\" FIXME: need a thread-safety statement about the *_l functions +.SH STANDARDS +.TP +.BR isalnum () +.TQ +.BR isalpha () +.TQ +.BR iscntrl () +.TQ +.BR isdigit () +.TQ +.BR isgraph () +.TQ +.BR islower () +.TQ +.BR isprint () +.TQ +.BR ispunct () +.TQ +.BR isspace () +.TQ +.BR isupper () +.TQ +.BR isxdigit () +.TQ +.BR isblank () +C11, POSIX.1-2008. +.TP +.BR isascii () +.TQ +.BR isalnum_l () +.TQ +.BR isalpha_l () +.TQ +.BR isblank_l () +.TQ +.BR iscntrl_l () +.TQ +.BR isdigit_l () +.TQ +.BR isgraph_l () +.TQ +.BR islower_l () +.TQ +.BR isprint_l () +.TQ +.BR ispunct_l () +.TQ +.BR isspace_l () +.TQ +.BR isupper_l () +.TQ +.BR isxdigit_l () +POSIX.1-2008. +.TP +.BR isascii_l () +GNU. +.SH HISTORY +.TP +.BR isalnum () +.TQ +.BR isalpha () +.TQ +.BR iscntrl () +.TQ +.BR isdigit () +.TQ +.BR isgraph () +.TQ +.BR islower () +.TQ +.BR isprint () +.TQ +.BR ispunct () +.TQ +.BR isspace () +.TQ +.BR isupper () +.TQ +.BR isxdigit () +C89, POSIX.1-2001. +.TP +.BR isblank () +C99, POSIX.1-2001. +.TP +.BR isascii () +POSIX.1-2001 (XSI). +.IP +POSIX.1-2008 marks it as obsolete, +noting that it cannot be used portably in a localized application. +.TP +.BR isalnum_l () +.TQ +.BR isalpha_l () +.TQ +.BR isblank_l () +.TQ +.BR iscntrl_l () +.TQ +.BR isdigit_l () +.TQ +.BR isgraph_l () +.TQ +.BR islower_l () +.TQ +.BR isprint_l () +.TQ +.BR ispunct_l () +.TQ +.BR isspace_l () +.TQ +.BR isupper_l () +.TQ +.BR isxdigit_l () +glibc 2.3. +POSIX.1-2008. +.TP +.BR isascii_l () +glibc 2.3. +.SH CAVEATS +The standards require that the argument +.I c +for these functions is either +.B EOF +or a value that is representable in the type +.IR "unsigned char" ; +otherwise, +the behavior is undefined. +If the argument +.I c +is of type +.IR char , +it must be cast to +.IR "unsigned char" , +as in the following example: +.PP +.in +4n +.EX +char c; +\&... +res = toupper((unsigned char) c); +.EE +.in +.PP +This is necessary because +.I char +may be the equivalent of +.IR "signed char" , +in which case a byte where the top bit is set would be sign extended when +converting to +.IR int , +yielding a value that is outside the range of +.IR "unsigned char" . +.PP +The details of what characters belong to which class depend on the +locale. +For example, +.BR isupper () +will not recognize an A-umlaut (\(:A) as an uppercase letter in the default +.B "C" +locale. +.SH SEE ALSO +.BR iswalnum (3), +.BR iswalpha (3), +.BR iswblank (3), +.BR iswcntrl (3), +.BR iswdigit (3), +.BR iswgraph (3), +.BR iswlower (3), +.BR iswprint (3), +.BR iswpunct (3), +.BR iswspace (3), +.BR iswupper (3), +.BR iswxdigit (3), +.BR newlocale (3), +.BR setlocale (3), +.BR toascii (3), +.BR tolower (3), +.BR toupper (3), +.BR uselocale (3), +.BR ascii (7), +.BR locale (7) |