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diff --git a/unix/os/doc/zopntx.hlp b/unix/os/doc/zopntx.hlp new file mode 100644 index 00000000..b2f008e1 --- /dev/null +++ b/unix/os/doc/zopntx.hlp @@ -0,0 +1,55 @@ +.help zopntx May84 "System Interface" +.ih +NAME +zopntx -- open a text file +.ih +SYNOPSIS +.nf +zopntx (osfn, mode, chan) + +packed char osfn[] # OS filename +int mode # access mode +int chan # OS channel assigned to file +.fi +.ih +DESCRIPTION +The text file \fIosfn\fR is opened with access mode \fImode\fR and +assigned the channel \fIchan\fR. The legal access modes for text files +are as follows: + +.nf + READ_ONLY 1 open existing file for reading + READ_WRITE 2 ** NOT SUPPORTED FOR TEXT FILES ** + WRITE_ONLY 3 same as append mode + APPEND 4 open or create for appending + NEW_FILE 5 create for appending +.fi + +If a nonexistent text file is opened for appending the file is created, +i.e., appending to a nonexistent file is equivalent to mode NEW_FILE. +READ_WRITE mode is not supported for text files since text file i/o is +sequential. +.ih +RETURN VALUE +ERR is returned if the named file does not exist, cannot be opened with the +specified access mode, cannot be created, or if an illegal mode is specified. +If the operation is successful the nonegative magic channel number assigned +by the kernel to the file is returned in \fIchan\fR. +.ih +NOTES +FIO will not call \fBzopntx\fR to open a new file if a file with the same +name already exists. FIO will instead either delete the file (if file clobber +is enabled) or take an error action. FIO does not assume anything about the +file position at open time; \fBzsektx\fR is called shortly after \fBzopntx\fR +to position the file to either BOF or EOF depending on the access mode. + +The file access permissions (owner, group, world permissions) of a new file +are set by the kernel to either host system default values or to user definable +values when the file is created. The technique by which this is done is machine +dependent. Many systems provide an automatic system default set of +permissions, e.g., read permission for everyone but write permission only +for the owner, but give the user the option of globally overriding the default. +.ih +SEE ALSO +zclstx, zfiotx, zopnbf +.endhelp |