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Full Discussion: Understanding the output command
Top Forums UNIX for Dummies Questions & Answers Understanding the output command Post 302386816 by Corona688 on Wednesday 13th of January 2010 04:54:30 PM
Old 01-13-2010
Quote:
Originally Posted by Ariean
I am missing something what do u mean by standard error? i understand standard output is the output printed on screen when i execute the script. But i didn't understand "2>&1" part, whats happening over there?

Thanks,
Ariean
By tradition, a UNIX process has three default streams: standard input(stdin), standard output(stdout), and standard error(stderr). stdin is represents the terminal keyboard as file descriptor 0, stdout represents the terminal screen as file descriptor 1, and stderr is also directed to the terminal screen as file descriptor 2.

The idea with having two files going to the terminal is to keep data and error messages separate. You can redirect the data output of a process into a file and still see human-readable error messages on your terminal. It also helps keep error messages OUT of data files since other programs probably won't need or understand them.

Here they're redirecting both stdout and stderr into the data file, for better or for worse. The "2>&1" bit tells it to redirect FD 2, stderr, to the same destination as FD 1, stdout.
This User Gave Thanks to Corona688 For This Post:
Ariean
 

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LEARN ABOUT CENTOS

paps

PAPS(1) 						      General Commands Manual							   PAPS(1)

NAME

       paps - UTF-8 to PostScript converter using Pango

SYNOPSIS

       paps [options] files...

DESCRIPTION

       paps reads a UTF-8 encoded file and generates a PostScript language rendering of the file. The rendering is done by creating outline curves
       through the pango ft2 backend.

OPTIONS

       These programs follow the usual GNU command line syntax, with long options starting with  two  dashes  (`-').   A  summary  of  options	is
       included below.

       --landscape
	      Landscape output. Default is portrait.

       --columns=cl
	      Number of columns output. Default is 1.

       --font=desc
	      Set the font description. Default is Monospace 12.

       --rtl  Do rtl layout.

       --paper ps
	      Choose paper size. Known paper sizes are legal, letter, a4. Default is A4.

       --bottom-margin=bm
	      Set bottom margin in postscript points (1/72 inch). Default is 36.

       --top-margin=tm
	      Set top margin. Default is 36.

       --left-margin=lm
	      Set left margin. Default is 36.

       --right-margin=rm
	      Set right margin. Default is 36.

       --help Show summary of options.

       --header
	      Draw page header for each page.

       --markup
	      Interpret the text as pango markup.

       --encoding=ENCODING
	      Assume the documentation encoding is ENCODING.

       --lpi  Set the lines per inch. This determines the line spacing.

       --cpi  Set the characters per inch. This is an alternative method of specifying the font size.

       --stretch-chars
	      Indicates  that  characters  should be stretched in the y-direction to fill up their vertical space. This is similar to the texttops
	      behaviour.

AUTHOR

       paps was written by Dov Grobgeld <dov.grobgeld@gmail.com>.

       This manual page was written by Lior Kaplan <kaplan@debian.org>, for the Debian project (but may be used by others).

								  April  17, 2006							   PAPS(1)
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