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diff --git a/man-pages-posix-2013/man3p/errno.3p b/man-pages-posix-2013/man3p/errno.3p new file mode 100644 index 0000000..8a3f9b3 --- /dev/null +++ b/man-pages-posix-2013/man3p/errno.3p @@ -0,0 +1,106 @@ +'\" et +.TH ERRNO "3P" 2013 "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 +errno +\(em error return value +.SH SYNOPSIS +.LP +.nf +#include <errno.h> +.fi +.SH DESCRIPTION +The lvalue +.IR errno +is used by many functions to return error values. +.P +Many functions provide an error number in +.IR errno , +which has type +.BR int +and is defined in +.IR <errno.h> . +The value of +.IR errno +shall be defined only after a call to a function for which it is +explicitly stated to be set and until it is changed by the next +function call or if the application assigns it a value. The value of +.IR errno +should only be examined when it is indicated to be valid by a +function's return value. Applications shall obtain the definition of +.IR errno +by the inclusion of +.IR <errno.h> . +No function in this volume of POSIX.1\(hy2008 shall set +.IR errno +to 0. The setting of +.IR errno +after a successful call to a function is unspecified unless the +description of that function specifies that +.IR errno +shall not be modified. +.P +It is unspecified whether +.IR errno +is a macro or an identifier declared with external linkage. If a macro +definition is suppressed in order to access an actual object, or a +program defines an identifier with the name +.IR errno , +the behavior is undefined. +.P +The symbolic values stored in +.IR errno +are documented in the ERRORS sections on all relevant pages. +.SH "RETURN VALUE" +None. +.SH ERRORS +None. +.LP +.IR "The following sections are informative." +.SH EXAMPLES +None. +.SH "APPLICATION USAGE" +Previously both POSIX and X/Open documents were more restrictive than +the ISO\ C standard in that they required +.IR errno +to be defined as an external variable, whereas the ISO\ C standard required only +that +.IR errno +be defined as a modifiable lvalue with type +.BR int . +.P +An application that needs to examine the value of +.IR errno +to determine the error should set it to 0 before a function call, then +inspect it before a subsequent function call. +.SH RATIONALE +None. +.SH "FUTURE DIRECTIONS" +None. +.SH "SEE ALSO" +.IR "Section 2.3" ", " "Error Numbers" +.P +The Base Definitions volume of POSIX.1\(hy2008, +.IR "\fB<errno.h>\fP" +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 7, Copyright (C) 2013 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. +(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html . + +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 . |