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Full Discussion: Is there a way to tee stderr from a command that's redirecting error to a file?
Top Forums Shell Programming and Scripting Is there a way to tee stderr from a command that's redirecting error to a file? Post 302356166 by sumgi on Thursday 24th of September 2009 05:52:46 PM
Old 09-24-2009
I have come to a solution but I doubt I will use it since it involves editing users commands dynamically.

My solution comes in two parts:

1. Use a recursive function to track down any error redirection in the issued command:

  • Return nothing if redirection is not taking place
  • If redirection is to another channel (Ex: Stdout is channel 1) call the function again on the new channel, if the function returns nothing pass the channel otherwise pass the returned value
  • Return the file being redirected to if there is one
  • Return null if the user is redirecting to /dev/null or has turned off that channel(Ex. #>&-)

2. Use named pipes created from the mkfifo command to redirect errors from the users command to both the user file and a temp file to use by the wrapper.


Then when I think about redirection happening before a pipe

Ex:
Code:
du -sk /path/* 2> log/du.err | sort -rn > log/sort.log 2>&1

Now I would need to run the command through a loop and do this process for each piped command, creating a named pipe for each redirection.

If someone sees an easier way great but this is the only way I see to do it. It's my opinion that telling users the errors will be located in a master log file will be easier.
 

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LEARN ABOUT OSF1

script

script(1)						      General Commands Manual							 script(1)

NAME

       script - Makes a transcript of terminal session

SYNOPSIS

       script [-a] [file]

       The script command makes a transcript of everything printed on your terminal.

OPTIONS

       Appends the transcript to file rather than writing it to file.

OPERANDS

       The name of an output file that will contain the transcript of the session.  If this parameter is omitted, the file typescript is written.

DESCRIPTION

       The transcript is written to file, or appended to file if the -a option is given.  If no file name is given, the transcript is saved in the
       file typescript.

       The script ends when the forked shell exits.

       This program is useful when you are using a CRT and want a hard-copy record of the dialog (for example, a technical writer might create	an
       example of a working session this way).

       If you specify the -a option and the file does not exist, it is created.

       If you do not specify the -a option and the file exists, it is replaced.

RESTRICTIONS

       The  script command requires a streams based terminal.  In single user mode, streams may not be enabled.  Under these circumstances, script
       will exit with no action.  If you are the superuser and need to run this command in single user mode, use the  following  special  instruc-
       tions.

   Enabling Streams
       If it is necessary to enable a streams environment in the single user mode, enter the command /sbin/init.d/streams.  This command is avail-
       able to the superuser only.

SEE ALSO

       Commands:  autopush(8), cat(1), echo(1), strsetup(8), tee(1)

       System Administration

																	 script(1)
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