mf_errprintf.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 errprintf()}
{hline}
{* index errprintf()}{...}
{* index SMCL}{...}
{* index as error}{...}


{title:Title}

{p 4 4 2}
{bf:[M-5] errprintf() -- Format output and display as error message}


{title:Syntax}

{p 8 12 2}
{it:void}
{cmd:errprintf(}{it:string scalar fmt}{cmd:,}
{it:r1}{cmd:,}
{it:r2}{cmd:,}
...{cmd:,}
{it:rN}{cmd:)}


{title:Description}

{p 4 4 2}
{cmd:errprintf()} is a convenience tool for displaying an error message.

{p 4 4 2}
{cmd:errprintf(}...{cmd:)} is equivalent to
{cmd:printf(}{it:...}{cmd:)} 
except that it executes
{cmd:displayas("error")}
before the {cmd:printf()} is executed;
see
{bf:{help mf_printf:[M-5] printf()}}
and 
{bf:{help mf_displayas:[M-5] displayas()}}


{title:Remarks}

{p 4 4 2}
You have written a program.  At one point in the code, you have variable 
{cmd:fn} that should contain the name of an existing file:  

		{cmd:if (!fileexists(fn)) {c -(}}
			// {it:you wish to display the error message}
			// {it:file ____ not found}
			{cmd:exit(601)}
		{cmd:{c )-}}

{p 4 4 2}
One solution is

		{cmd:if (!fileexists(fn)) {c -(}}
			{cmd:displayas("error")}
			{cmd:printf("file %s not found\n", fn)}
			{cmd:exit(601)}
		{cmd:{c )-}}

{p 4 4 2}
Equivalent is

		{cmd:if (!fileexists(fn)) {c -(}}
			{cmd:errprintf("file %s not found\n", fn)}
			{cmd:exit(601)}
		{cmd:{c )-}}

{p 4 4 2}
It is important that you either {cmd:displayas("error")} before using 
{cmd:printf()} or that you use {cmd:errprintf()}, in order to ensure 
that you error message is displayed (is not suppressed by a 
{cmd:quietly}) and that it is displayed in red; see 
{bf:{help mf_displayas:[M-5] displayas()}}.


{title:Conformability}

{p 4 8 2}
{cmd:errprintf(}{it:fmt}{cmd:,}
{it:r1}{cmd:,}
{it:r2}{cmd:,}
...{cmd:,}
{it:rN}{cmd:)}
{p_end}
	      {it:fmt}:  1 {it:x} 1
	       {it:r1}:  1 {it:x} 1
	       {it:r2}:  1 {it:x} 1
	       ...
	       {it:rN}:  1 {it:x} 1
	   {it:result}:  {it:void}


{title:Diagnostics}

{p 4 4 2}
{cmd:errprintf()} aborts with error if 
a {cmd:%}{it:fmt} is misspecified, if a numeric {cmd:%}{it:fmt} 
corresponds to a string result or a string {cmd:%}{it:fmt} 
corresponds to a numeric result, or there are too few or too many 
{cmd:%}{it:fmts} in {it:fmt} relative 
to the number of {it:results} specified.


{title:Source code}

{p 4 4 2}
Function is built-in.


{title:Also see}

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

{p 4 13 2}
Online:  help for 
{bf:{help mf_printf:[M-5] printf()}},
{bf:{help mf_displayas:[M-5] displayas()}};
{bf:{help m4_io:[M-4] io}}
{p_end}