Sponsored Content
Full Discussion: Output redirection meaning
Top Forums Shell Programming and Scripting Output redirection meaning Post 302422187 by pseudocoder on Monday 17th of May 2010 05:08:39 PM
Old 05-17-2010
Both, STDERR (2) and STDOUT (1) are redirected to nowhere. It's practical when you just want to check the return status of preceding command and don't want to see any output e.g. STDOUT or STDERR.

Edit: Small improvement of my previous answer for better understanding:
Code:
ls /etc/*.txt > /dev/null 2>&1

Redirect STDOUT to /dev/null respectively don't show output; redirect STDERR to STDOUT

Last edited by pseudocoder; 05-17-2010 at 06:29 PM..
 

10 More Discussions You Might Find Interesting

1. Solaris

netstat -an -- meaning of the output

Dear Experts, I put below command- could you please describe the outputs column- let me describe some them- col_1: (10.131.60.48.55880) The IP address of the local computer and the port number being used for this particular connection appear in the Local Address column. col_2:... (3 Replies)
Discussion started by: thepurple
3 Replies

2. UNIX for Dummies Questions & Answers

Output file redirection

Suppose I have a file named a When I write cat a>a The following error message is displayed cat: a: input file is output file and my file a is truncated to zero size. Also the exit status of the last command is 1 Can someone tell me what actually happens when I do so? (1 Reply)
Discussion started by: aagajaba
1 Replies

3. UNIX for Advanced & Expert Users

what is the meaning of the following redirection

Hello bash experts., I was doing some experimentations to better understand the following redirection., $Output = `sh -c \"$Cmd 2>&1 1>&2\"`; It is actually the line used in one of the perl program, but the technique i am trying to understand is related to shell scripting. So is there... (5 Replies)
Discussion started by: thegeek
5 Replies

4. Shell Programming and Scripting

redirection and output

I'm redirecting the output of a command to a logfile, however, if the user is on a terminal I would also like the output to be displayed on the screen. tar tvf some_tarfile >Logfile if the user is on a term then have the output to the Logfile and also be displayed on the screen at the same... (2 Replies)
Discussion started by: nck
2 Replies

5. Shell Programming and Scripting

Redirection output

Hi there I have a script that runs but it outputs everything onto the screen instead of a file. I've tried using the > outputfile.txt however all it does is dump the output to the screen and creates an outputfile.txt but doesn't put anything in that file. Any help would be appreciated ... (6 Replies)
Discussion started by: kma07
6 Replies

6. Shell Programming and Scripting

Output redirection

We have an application here that does some table queries and then prints the result on screen. I do not have the code of this application (which i will just call "queryCommand"), but what it does is that you call it with some parameters and it prints some info about the query and then the... (5 Replies)
Discussion started by: jolateh
5 Replies

7. UNIX for Dummies Questions & Answers

Output redirection

Hello i am trying to write a script that will redirect the output to a certain file. Here is the code so far: #!/bin/bash ps -e | sort | more > psfile When I execute the script nothing happens since i assume the output was redirected to the file called psfile. When I try to look at the... (1 Reply)
Discussion started by: mfruiz34
1 Replies

8. Shell Programming and Scripting

Redirection of ls -l output

Hi I am making a script where i want to redirect the output of ls -l to a file Example #ls -l fil1.txt > /opt/temp/a.txt ac: No such file or directory I want to capture output of this command like here output is ac: No such file or directory can anyone help (4 Replies)
Discussion started by: anish19
4 Replies

9. Shell Programming and Scripting

output redirection

Hi all I was wondering if there was a slicker way of doing this without the file - awk '{print $2}' FS=":" "${FILE}" > "${TMPFILE}" { read M_GRP_ID || m_fail 1 "Error: Read failed 1 (${FUNCNAME})" read M_GRP_WAIT || m_fail 1 "Error: Read failed 2 (${FUNCNAME})" }... (6 Replies)
Discussion started by: steadyonabix
6 Replies

10. Shell Programming and Scripting

For loop output redirection

Hi All, i have below for loop of which i am trying to redirect output in a file: for i in `/usr/sbin/ifconfig -a | awk '/flags/ {print $1}' | grep -v lo | sed 's/://g'` do ifconfig $i dhcp status done >> /tmp/logfile but instead the output is appearing as stdout on screen rather than... (12 Replies)
Discussion started by: omkar.jadhav
12 Replies
XTERMCONTROL(1) 						   User Commands						   XTERMCONTROL(1)

NAME
xtermcontrol - dynamic control of XFree86 xterm properties. SYNOPSIS
xtermcontrol [OPTIONS]... DESCRIPTION
xtermcontrol makes it easy to change colors, title, font and geometry of a running XFree86 xterm(1), as well as to report the current set- tings of the aforementioned properties. Window manipulations de-/iconify, raise/lower, maximize/restore and reset are also supported. To complete the feature set; xtermcontrol lets advanced users issue any xterm control sequence of their choosing. OPTIONS
--fg=COLOR Set foreground color (see also COLOR NAMES). --bg=COLOR Set background color. --colorN=COLOR Set N'th [0-15] color. --highlight=COLOR Set highlight color. --cursor=COLOR Set cursor color. --mouse-fg=COLOR Set mouse pointer foreground color. --mouse-bg=COLOR Set mouse pointer background color. --font=FONT Set font name (see also FONT NAMES). Alternatively it is possible to specify a fontmenu index as '#[0-6]' or navigate the fontmenu by relative sizes as '#+N' or '#-N', where N is an optional integer. --title=STRING Set window title. Note that mechanisms like the bash(1) PROMPT_COMMAND may overwrite the title. --geometry=WIDTHxHEIGHT+XOFF+YOFF Set size and/or position. Through its control sequences the xterm only recognize positive XOFF and YOFF offsets, which are pixels relative to the upper left hand corner of the display. xtermcontrol is therefore unable to handle negative offsets as described in the X(7x) GEOMETRY SPECIFICATIONS and therefore truncates negative values to zero. --get-fg Report foreground color. --get-bg Report background color. --get-colorN Report N'th [0-15] color. --get-highlight Report highlight color. --get-cursor Report cursor color. --get-mouse-fg Report mouse pointer foreground color. --get-mouse-bg Report mouse pointer background color. --get-font Report font. --get-title Report window title. --get-geometry Report size and position. The size of the text area is reported in characters and the position is reported in pixels relative to the upper left hand corner of the display. --maximize Maximize window. --restore Restore maximized window. --iconify Iconify window. --de-iconify De-iconify window. --raise Raise window. --lower Lower window. --reset Full reset. --raw=CTLSEQS Issue raw control sequence (see also XTERM CONTROL SEQUENCES). --file=FILE Force xtermcontrol to read configurations (see also CONFIGURATION) from FILE instead of the standard personal initialization file ~/.xtermcontrol. --force, -f Skip TERM environment variable check. --verbose, -v Print verbose reports. --help, -h Print help message and exit. --version Print the version number and exit. CONFIGURATION
xtermcontrol reads a default, ~/.xtermcontrol, or a user specified configuration file on startup. Each line in the file is either a com- ment or contains an attribute. Attributes consist of a keyword and an associated value: keyword = value # comment The valid keyword/value combinations are: foreground="COLOR" background="COLOR" highlight="COLOR" cursor="COLOR" mouse-foreground="COLOR" mouse-background="COLOR" geometry="WIDTHxHEIGHT+XOFF+YOFF" font="FONT" color0="COLOR" color1="COLOR" color2="COLOR" color3="COLOR" color4="COLOR" color5="COLOR" color6="COLOR" color7="COLOR" color8="COLOR" color9="COLOR" color10="COLOR" color11="COLOR" color12="COLOR" color13="COLOR" color14="COLOR" color15="COLOR" Whitespace is ignored in attributes unless within a quoted value. The character '#' is taken to begin a comment. Each '#' and all remaining characters on that line is ignored. FONT NAMES
xtermcontrol accepts any X(7x) FONT NAMES. Font names like '-adobe-courier-medium-r-normal--10-100-75-75-m-60-iso8859-1' are very cumber- some to write, so it is convenient to make use of aliases, e.g. 'fixed' or '8x13', if present in fonts.alias files of the font directo- ries. COLOR NAMES
xtermcontrol accepts any X(7x) COLOR NAMES. Basically this means that colors are specified by name or rgb value, e.g. 'blue', 'rgb:0000/0000/FFFF' or '#00F'. Colors are typically reported by the xterm in a device-dependent numerical form, e.g. 'rgb:0000/0000/FFFF'. Note that old syntax rgb values should always be quoted to avoid '#' being interpreted as the beginning of a comment by the shell (see also FILES). XTERM CONTROL SEQUENCES
The secret behind xtermcontrol is xterm control sequences. All the possible (there are a plethora of them) control sequences are documented in ctlseqs.txt, found in the xterm(1) distribution (see also FILES). TROUBLESHOOTING
If read/write permissions on the tty's are changed so that special group membership is required to be able to write to the pseudo terminal, the easiest workaround is to install xtermcontrol setuid root. Xterm(1) has three resources, allowWindowOps, allowTitleOps, and allowFontOps, that enables or disables special operations which xtermcon- trol relies on. If any of these resources are set (or defaults) to 'false' xtermcontrol may hang. The resources corresponds to xtermcon- trol options as: allowWindowOps: --raise --lower --restore --maximize --iconify --de-iconify --get-title --geometry --get-geometry allowTitleOps: --title allowFontOps: --font --get-font All three resources can usually be enabled for the current xterm session via a menu; ctrl+rightclick and look for menu item names like 'Allow Window Ops'. To set these resource values persistently you can add the following to either your local ~/.Xdefaults file, or to a system-wide resource file like /etc/X11/app-defaults/XTerm: *VT100.allowWindowOps: true *VT100.allowTitleOps: true *VT100.allowFontOps: true FILES
<XRoot>/X11/rgb.txt Default rgb color name file location. ctlseqs.txt Xterm control sequences documentation. Distributed with xterm from http://dickey.his.com/xterm/ SEE ALSO
xterm(1), X(7x) COPYRIGHT
Copyright (C) 2002-2009 Jess Thrysoee <jess@thrysoee.dk> xtermcontrol 2.10 October 17, 2009 XTERMCONTROL(1)
All times are GMT -4. The time now is 11:39 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy