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diff --git a/man-pages-posix-2017/man3p/islower.3p b/man-pages-posix-2017/man3p/islower.3p new file mode 100644 index 0000000..891b1ae --- /dev/null +++ b/man-pages-posix-2017/man3p/islower.3p @@ -0,0 +1,171 @@ +'\" et +.TH ISLOWER "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" +.SH PROLOG +This manual page is part of the POSIX Programmer's Manual. +The Linux implementation of this interface may differ (consult +the corresponding Linux manual page for details of Linux behavior), +or the interface may not be implemented on Linux. +.\" +.SH NAME +islower, +islower_l +\(em test for a lowercase letter +.SH SYNOPSIS +.LP +.nf +#include <ctype.h> +.P +int islower(int \fIc\fP); +int islower_l(int \fIc\fP, locale_t \fIlocale\fP); +.fi +.SH DESCRIPTION +For +\fIislower\fR(): +The functionality described on this reference page is aligned with the +ISO\ C standard. Any conflict between the requirements described here and the +ISO\ C standard is unintentional. This volume of POSIX.1\(hy2017 defers to the ISO\ C standard. +.P +The +\fIislower\fR() +and +\fIislower_l\fR() +functions shall test whether +.IR c +is a character of class +.BR lower +in the current locale, +or in the locale represented by +.IR locale , +respectively; see the Base Definitions volume of POSIX.1\(hy2017, +.IR "Chapter 7" ", " "Locale". +.P +The +.IR c +argument is an +.BR int , +the value of which the application shall ensure is a character +representable as an +.BR "unsigned char" +or equal to the value of the macro EOF. If the argument has any other +value, the behavior is undefined. +.P +The behavior is undefined if the +.IR locale +argument to +\fIislower_l\fR() +is the special locale object LC_GLOBAL_LOCALE or is not a valid locale +object handle. +.SH "RETURN VALUE" +The +\fIislower\fR() +and +\fIislower_l\fR() +functions shall return non-zero if +.IR c +is a lowercase letter; otherwise, they shall return 0. +.SH ERRORS +No errors are defined. +.LP +.IR "The following sections are informative." +.SH EXAMPLES +.SS "Testing for a Lowercase Letter" +.P +Two examples follow, the first using +\fIislower\fR(), +the second using multiple concurrent locales and +\fIislower_l\fR(). +.P +The examples test whether the value is a lowercase letter, +based on the current locale, then use it as part of a key value. +.sp +.RS 4 +.nf + +/* Example 1 -- using islower() */ +#include <ctype.h> +#include <stdlib.h> +#include <locale.h> +\&... +char *keystr; +int elementlen, len; +unsigned char c; +\&... +setlocale(LC_ALL, ""); +\&... +len = 0; +while (len < elementlen) { + c = (unsigned char) (rand() % 256); +\&... + if (islower(c)) + keystr[len++] = c; + } +\&... +.P +/* Example 2 -- using islower_l() */ +#include <ctype.h> +#include <stdlib.h> +#include <locale.h> +\&... +char *keystr; +int elementlen, len; +unsigned char c; +\&... +locale_t loc = newlocale (LC_ALL_MASK, "", (locale_t) 0); +\&... +len = 0; +while (len < elementlen) { + c = (unsigned char) (rand() % 256); +\&... + if (islower_l(c, loc)) + keystr[len++] = c; + } +\&... +.fi +.P +.RE +.SH "APPLICATION USAGE" +To ensure applications portability, especially across natural +languages, only these functions and the functions in the reference pages +listed in the SEE ALSO section should be used for character classification. +.SH RATIONALE +None. +.SH "FUTURE DIRECTIONS" +None. +.SH "SEE ALSO" +.IR "\fIisalnum\fR\^(\|)", +.IR "\fIisalpha\fR\^(\|)", +.IR "\fIisblank\fR\^(\|)", +.IR "\fIiscntrl\fR\^(\|)", +.IR "\fIisdigit\fR\^(\|)", +.IR "\fIisgraph\fR\^(\|)", +.IR "\fIisprint\fR\^(\|)", +.IR "\fIispunct\fR\^(\|)", +.IR "\fIisspace\fR\^(\|)", +.IR "\fIisupper\fR\^(\|)", +.IR "\fIisxdigit\fR\^(\|)", +.IR "\fIsetlocale\fR\^(\|)", +.IR "\fIuselocale\fR\^(\|)" +.P +The Base Definitions volume of POSIX.1\(hy2017, +.IR "Chapter 7" ", " "Locale", +.IR "\fB<ctype.h>\fP", +.IR "\fB<locale.h>\fP" +.\" +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1-2017, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 7, 2018 Edition, +Copyright (C) 2018 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. +In the event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.opengroup.org/unix/online.html . +.PP +Any typographical or formatting errors that appear +in this page are most likely +to have been introduced during the conversion of the source files to +man page format. To report such errors, see +https://www.kernel.org/doc/man-pages/reporting_bugs.html . |