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returning_20errors_20from_20windows_20commands [2018/03/31 14:19]
127.0.0.1 external edit 		returning_20errors_20from_20windows_20commands [2018/04/14 18:22]
richardrussell Added syntax highlighting
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 =====Returning errors from Windows commands===== =====Returning errors from Windows commands=====
  
-//by Jonathan Harston, August 2010//\\ \\  The OSCLI command can be used to execute a Windows command. However, if the command fails, no error is generated, the Windows command interpreter merely //displays// an error message. You may see this appearing in a DOS command box before it quickly disappears.\\ \\  However, the Windows command interpreter and properly-written commands output error message to the //standard-error// output stream. This can be redirected to a file, and then any contents examined later. The following function does this.\\ \\ +//by Jonathan Harston, August 2010//\\ \\  The OSCLI command can be used to execute a Windows command. However, if the command fails, no error is generated, the Windows command interpreter merely //displays// an error message. You may see this appearing in a DOS command box before it quickly disappears.\\ \\  However, the Windows command interpreter and properly-written commands output error message to the //standard-error// output stream. This can be redirected to a file, and then any contents examined later. The following function does this. 
 + 
 +<code bb4w> 
         DEF FNwin_cmd(cli$)         DEF FNwin_cmd(cli$)
         LOCAL ch%,err$,tmp$:tmp$=@tmp$+STR$TIME         LOCAL ch%,err$,tmp$:tmp$=@tmp$+STR$TIME
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         err$=GET$#ch%:CLOSE#ch%:OS."Delete "+tmp$         err$=GET$#ch%:CLOSE#ch%:OS."Delete "+tmp$
         =err$         =err$
-\\  This redirects the error output to a file, then reads that file to see if anything has been output to it. Bear in mind that if the called command displays its error reports to //standard-out// instead of //standard-error//, then it will return an empty string.\\ \\ +</code> 
 + 
 +This redirects the error output to a file, then reads that file to see if anything has been output to it. Bear in mind that if the called command displays its error reports to //standard-out// instead of //standard-error//, then it will return an empty string. 
 ===== Examples ===== ===== Examples =====
 +<code>
       >PRINT FNwin_cmd("junk")       >PRINT FNwin_cmd("junk")
       'junk' is not recognised as an internal or external command.       'junk' is not recognised as an internal or external command.
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       >       >
-\\  Note that, as opposed to OSCLI itself, the command is //always// passed to Windows. In the second example above, the Windows **DIR** command is executed, which will result in a directory listing appearing in a DOS command box before quickly diappearing.\\ \\ +</code> 
 + 
 +Note that, as opposed to OSCLI itself, the command is //always// passed to Windows. In the second example above, the Windows **DIR** command is executed, which will result in a directory listing appearing in a DOS command box before quickly disappearing. 
 ===== References ===== ===== References =====
  
   * http://rtrussell.co.uk/bbcwin/manual/bbcwin8.html#opsys   * http://rtrussell.co.uk/bbcwin/manual/bbcwin8.html#opsys
returning_20errors_20from_20windows_20commands.txt · Last modified: 2021/12/19 10:47 by jgharston

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