mf_unlink.hlp

是一个经济学管理应用软件 很难找的 但是经济学学生又必须用到

{smcl}
{* 31mar2005}{...}
{cmd:help mata unlink()}
{hline}
{* index unlink()}{...}
{* index _unlink()}{...}
{* index file processing}{...}
{* index erase}{...}

{title:Title}

{p 4 4 2}
{bf:[M-5] unlink() -- Erase file}


{title:Syntax}

{p 8 12 2}
{it:void}{bind:        }
{cmd:unlink(}{it:real scalar filename}{cmd:)}

{p 8 12 2}
{it:real scalar}
{cmd:_unlink(}{it:real scalar filename}{cmd:)}


{title:Description}

{p 4 4 2}
{cmd:unlink()} erases {it:filename} if it exists; does nothing if 
{it:filename} does not exist, and aborts with error if {it:filename} 
exists but cannot be erased.

{p 4 4 2}
{cmd:_unlink()} does the same, except that, if {it:filename} cannot be 
erased, rather than aborting with error, {cmd:_unlink()} returns 
a negative error code.  {cmd:_unlink()} returns 0 if {it:filename} 
was erased or {it:filename} did not exist.


{title:Remarks}

{p 4 4 2}
To remove directories, see {cmd:rmdir()} in
{bf:{help mf_chdir:[M-5] chdir()}}.


{title:Diagnostics}

{p 4 4 2}
{cmd:unlink(}{it:filename}{cmd:)}
aborts with error when {cmd:_unlink()} would give a negative result.

{p 4 4 2}
{cmd:_unlink(}{it:filename}{cmd:)} returns a negative result if the 
file cannot be erased and returns 0 otherwise.  
If the file did not exist, 0 is returned.
When there is an error, 
most commonly returned are -3602 (filename invalid) or -3621 (file is 
read-only).


{title:Source code}

{p 4 4 2}
Functions are built-in.


{title:Also see}

{p 4 13 2}
Manual:  {hi:[M-5] unlink()}

{p 4 13 2}
Online:  help for 
{bf:{help m4_io:[M-4] io}}
{p_end}