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diff --git a/man-pages-posix-2013/man3p/ftruncate.3p b/man-pages-posix-2013/man3p/ftruncate.3p new file mode 100644 index 0000000..e24175a --- /dev/null +++ b/man-pages-posix-2013/man3p/ftruncate.3p @@ -0,0 +1,161 @@ +'\" et +.TH FTRUNCATE "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 +ftruncate +\(em truncate a file to a specified length +.SH SYNOPSIS +.LP +.nf +#include <unistd.h> +.P +int ftruncate(int \fIfildes\fP, off_t \fIlength\fP); +.fi +.SH DESCRIPTION +If +.IR fildes +is not a valid file descriptor open for writing, the +\fIftruncate\fR() +function shall fail. +.P +If +.IR fildes +refers to a regular file, the +\fIftruncate\fR() +function shall cause the size of the file to be truncated to +.IR length . +If the size of the file previously exceeded +.IR length , +the extra data shall no longer be available to reads on the file. If +the file previously was smaller than this size, +\fIftruncate\fR() +shall increase the size of the file. If the file size is increased, +the extended area shall appear as if it were zero-filled. The value of +the seek pointer shall not be modified by a call to +\fIftruncate\fR(). +.P +Upon successful completion, if +.IR fildes +refers to a regular file, +\fIftruncate\fR() +shall mark for update the last data modification and last file +status change timestamps of the file and the S_ISUID and S_ISGID bits +of the file mode may be cleared. If the +\fIftruncate\fR() +function is unsuccessful, the file is unaffected. +.P +If the request would cause the file size to exceed the soft file size +limit for the process, the request shall fail and the implementation +shall generate the SIGXFSZ signal for the thread. +.P +If +.IR fildes +refers to a directory, +\fIftruncate\fR() +shall fail. +.P +If +.IR fildes +refers to any other file type, except a shared memory object, the +result is unspecified. +.P +If +.IR fildes +refers to a shared memory object, +\fIftruncate\fR() +shall set the size of the shared memory object to +.IR length . +.P +If the effect of +\fIftruncate\fR() +is to decrease the size of a memory mapped file +or a shared memory object +and whole pages beyond the new end were previously mapped, then the +whole pages beyond the new end shall be discarded. +.P +References to discarded pages shall result in the generation of a +SIGBUS signal. +.P +If the effect of +\fIftruncate\fR() +is to increase the size of a memory object, it is unspecified +whether the contents of any mapped pages between the old end-of-file +and the new are flushed to the underlying object. +.SH "RETURN VALUE" +Upon successful completion, +\fIftruncate\fR() +shall return 0; otherwise, \(mi1 shall be returned and +.IR errno +set to indicate the error. +.SH ERRORS +The +\fIftruncate\fR() +function shall fail if: +.TP +.BR EINTR +A signal was caught during execution. +.TP +.BR EINVAL +The +.IR length +argument was less than 0. +.TP +.BR EFBIG " or " EINVAL +.br +The +.IR length +argument was greater than the maximum file size. +.TP +.BR EFBIG +The file is a regular file and +.IR length +is greater than the offset maximum established in the open file +description associated with +.IR fildes . +.TP +.BR EIO +An I/O error occurred while reading from or writing to a file system. +.TP +.BR EBADF " or " EINVAL +.br +The +.IR fildes +argument is not a file descriptor open for writing. +.LP +.IR "The following sections are informative." +.SH EXAMPLES +None. +.SH "APPLICATION USAGE" +None. +.SH RATIONALE +None. +.SH "FUTURE DIRECTIONS" +None. +.SH "SEE ALSO" +.IR "\fIopen\fR\^(\|)", +.IR "\fItruncate\fR\^(\|)" +.P +The Base Definitions volume of POSIX.1\(hy2008, +.IR "\fB<unistd.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 . |