The tag has no wiki summary.

learn more… | top users | synonyms

0
votes
2answers
23 views

concatenate .out files

Can I combined multiple .out files with the cat command in bash or csh? Additionally I want only the header of first file to be concatenated and I was thinking of using the tail function for that. ...
1
vote
4answers
99 views

How can I output the difference between 2 files?

My file consists of the the following; roughly: username:username:username:username:username The above line continues to about 600 characters. I use the awk command in order to use it as an ...
4
votes
3answers
147 views

Adding comments using 'set -x'

Sometimes it is really handy to just add set -x to the top of your script to show all commands before they are executed. There is only one drawback creating scripts with a decent output: I don't ...
5
votes
1answer
154 views

ifconfig -a in a shell script

I am writing a shell script to start my network in my virtual machine on boot, since it does not do this right away for some reason with a snapshot of a virtual machine. Since the eth device starts ...
3
votes
1answer
49 views

redirect output for a command that takes in multiple arguments

this command is to redirect output of time to with multiple args: $ time wc test >wc.out 2>time.out unix programming environment book shows that the error output of time redirects to ...
8
votes
4answers
97 views

Save output of command that modifies environment into a variable

How to save output of a command that modifies environment into a variable? I'm using bash shell. Assume that I have: function f () { a=3; b=4 ; echo "`date`: $a $b"; } And now, I can use commands ...
1
vote
2answers
83 views

Do all Linux processes write EOF to stdout when they are terminating/have finished terminating?

I'm having trouble with sending shutdown -h 0 to a lxc Debian container (i.e. executing this command in the lxc) with with the python pexpect module (in a python script). In this module the user can ...
0
votes
3answers
48 views

how to export all numbers that are unique in few text files into another file?

I have a.txt,b.txt,c.txt. Each has different numbers as below: a.txt: 12 14 111 1 15 2 b.txt 12 18 22 23 1 2 c.txt 12 14 15 16 17 1200 The output should contains all the numbers from ...
0
votes
1answer
60 views

Pipe output from one command to another command's non standard input [duplicate]

I would like to do something similar to the following: which someapplciation | cd outputfrompreviouscommand The command which provides a directory and I would like to be able to make that output my ...
1
vote
1answer
58 views

Send copy of a script's output to a file

Say I have a Zsh script and that I would like to let it print output to STDOUT, but also copy (dump) its output to a file in disk. Moreover, the script starts with the following option set -o xtrace ...
3
votes
5answers
166 views

Listing directories based on size from largest to smallest on single line

I can use the following command to get a list of directories and their sizes and sort them from largest to smallest (in the example I renamed the directories to numbers to make this easier to ...
0
votes
1answer
24 views

Is it possible to save in a log everything the system outputs when I turn it on?

I am using a BeagleBone Black without any screen. It works fine, but sometimes when I turn it on it hangs and have to reset. I do not know why this is happening and since I cannot see whatever it is ...
1
vote
1answer
204 views

wget a file, logging the output and showing the output on prompt

In a bash script, I need to download a file from the web, for doing it i use wget command. I would log the output of wget command, and at "the same time" having the output prompting on terminal. I ...
0
votes
2answers
72 views

Shell Script Output not written to file properly

I tried to put the output of my program into a text file. It appends the echo commands to the file properly, but the imagemagick "compare" command is not appended to the file. It just STOUD's the ...
3
votes
1answer
58 views

How to actually test locale

So I know what locale does. Sets the output format of certain programs depending on what country/language you're in, for example 1000000 can be formatted like 1,000,000.00 1 000 000.00 1.000.000,00 ...
0
votes
1answer
199 views

LS Command output to file [closed]

I want to capture to a file the output of the ls command ls >> lsOutput.log This one works if executed in the command line. But when put inside a shell script (lsOutput.sh), returns ...
1
vote
2answers
251 views

Redirect grep error output to file

I wanted to capture to a file the errors being returned on the command line from grep. For example, grep foo.lookup No such file in directory I want to output that to a log file. This is my shell ...
4
votes
1answer
88 views

Is there a way to cat files as they are created? [duplicate]

Unlike the answer to this question (Can a bash script be hooked to a file?) I want to be able to see content of files that haven't been created yet as or after they are created. I don't know when ...
3
votes
2answers
137 views

Can zsh access the stdout of last run program?

I often use find or locate to find out about paths. (~) locate foobar.mmpz /home/progo/lmms/projects/foobar.mmpz The next step is often to open or otherwise manipulate the files. In a happy case ...
1
vote
1answer
179 views

how do i redirect output from tailf & grep to a file [duplicate]

All I wanted is to grep for specific lines in an ongoing log and re-direct it to some file.. tailf log | grep "some words" Now, I want the above command output to get re-directed to some file in ...
0
votes
1answer
48 views

Need to grep for specific lines from ongoing log and save it in some file

So, let me start with the overall outcome that i want to achieve. There is just one log, which will have info on certain devices, that i am upgrading. I use "tailf log" to monitor the log. Now, ...
-5
votes
2answers
82 views

What is the utility of piping to `/dev/null`?

Seeing that /dev/null's utility isn't immediately obvious to me, what is the use of /dev/null piping?
1
vote
1answer
143 views

Log output of GNU screen in real time?

I'm trying to get the output of a GNU Screen to a log file in real time. I've tried using tee, but that appears to not work with screen. The log function for screen will not work for this as it is not ...
0
votes
0answers
21 views

How to start command in bash without blocking console [duplicate]

There is a problem with starting some commands in bash. When this command is starting its standard output blocked of entering other commands. And till this command do not finishing no other command ...
11
votes
3answers
1k views

How to redirect the output of any command?

I'm trying to write a simple script to monitor my network status, without all of ping's output: ping -q -c 1 google.com > /dev/null && echo online || echo offline The problem is that ...
3
votes
0answers
61 views

Slow terminal print out

Just installed (netinstall) debian wheezy on a second machine newer machine however the terminal print out is noticeable slower than on the old machine although the new have faster CPU, RAM and HDD ...
3
votes
1answer
168 views

Why does grep change the length of output lines?

I often use dpkg or aptitude combined with grep when I want to list certain packages available or installed on my system, but I noticed that when I add | grep, the output lines look a little bit ...
1
vote
5answers
2k views

Pass the output of previous command to next as an argument

I've a command that outputs data to stdout (command1 -p=aaa -v=bbb -i=4). The output line can have the following value: rate (10%) - name: value - 10Kbps I want to grep that output in order to ...
2
votes
2answers
97 views

Show a sliding window of output from a program

I want to run a command (rsync -av) and only display 10 lines of output at any time. I have found a similar post, but I don't want to redirect it to a file. I want the output to be displayed ...
1
vote
1answer
95 views

Using sed output in another script or command

How can I use the output of sed in another script? For example (this doesn't work): sed -n "$COUNTER",1p /domains.csv | wget or sed -n "$COUNTER",1p /domains.csv > /myScript.sh As far as I ...
1
vote
1answer
49 views

Check standard output of a background processs in real time

Let us say I submit a process in the background and I want to see the stdout and stderr. In another post it was suggested: command > logfile 2>&1 & But when I do head logfile I do ...
2
votes
2answers
155 views

turn off buffering for `hping` in OpenBSD

It would appear that the output from hping is fully buffered when piped to perl for further line-by-line processing, so piping hping to perl doesn't work. hping --icmp-ts example.ca | perl -ne 'if ...
2
votes
2answers
51 views

How do I echo a line with linebreak at the end at window border? [duplicate]

I would like to echo a list all in one line, TAB separated (like ls does with files in one folder) for i in one two some_are_very_long_stuff b c; do echo $i; done will print one line per word: one ...
10
votes
2answers
110 views

Resource friendly way to indicate to user program is not hanging

I have a Perl script on a *nix system which, at one point, is processing 50,000 + lines of text. This takes some time. I am trying to find a resource friendly way to let the user know the program is ...
1
vote
1answer
100 views

Pipe not picking up stdout

I am running a java program from a OS X 10.8 bash terminal, and are trying to rederect the output it is producing. However, when either running this throug a pipe, or rederecting it to a file, the ...
3
votes
5answers
281 views

How to grep, then search and replace on the output?

I have some output from iconv, e.g. $ iconv -l | grep ISO | head -5 CSISO4UNITEDKINGDOM// CSISO10SWEDISH// CSISO11SWEDISHFORNAMES// CSISO14JISC6220RO// CSISO15ITALIAN// durrantm:~ How can I change ...
1
vote
2answers
344 views

What stream does perf use?

What stream does the perf command use!? I've been trying to capture it with (perf stat -x, -ecache-misses ./a.out>/dev/null) 2> results following http://stackoverflow.com/q/13232889/50305, ...
1
vote
1answer
65 views

strange behaviour of strings command [duplicate]

I am trying to capture mysql traffic and pass those traffic to strings command as follows: tcpdump -i any -s 0 -l -w - dst port 3306 | strings This is working as expected and printing all mysql ...
3
votes
4answers
1k views

Pipe the output of a command if it is successful

INPUT_FILE=`ls -rt $MY_DIR/FILE.*.xml | head -1 | xargs basename` I wanted to execute the second command (head -1) only if the first command is successful. How do I improve this command?
7
votes
3answers
1k views

Why does this 'at' command not print to the standard output?

I am a relative Linux novice. I am trying to learn how to use at so that I can schedule tasks to begin at a later time, without using sleep. I have been looking at this previous question for help. ...
4
votes
1answer
82 views

How to concat file and a line on-fly?

I would like to send to the stdout entire file + extra line. How to do this nicely? So far I did: for LINE in $(cat $INPUT_FILE) do echo $LINE done echo $EXTRA_LINE How to do this bash way (for ...
2
votes
1answer
2k views

How to disable VLC output in command-line mode?

When I play music on vlc or cvlc in terminal or console there is always this (shown below) non-stopping output that prevents me from issuing commands by pressing ENTER key. I want to disable it, I ...
8
votes
2answers
2k views

how to output text to both screen and file inside a shell script?

Currently I have a shell script which logs messages to a log file like this: log_file="/some/dir/log_file.log" echo "some text" >> $log_file do_some_command echo "more text" >> $log_file ...
1
vote
1answer
120 views

Have aptitude search print full package name

Environment: aptitude called in a script. I'm having problems with this command: aptitude search '?virtual' |grep ^v |grep -v i386|sort|uniq In particular if I do: aptitude search '?virtual' ...
10
votes
2answers
212 views

Is there a way to mirror USB outputs?

I'm currently writing a program for a project. It is for a braille reading system where I have a braille display connected via USB that is controlled by a program called brltty. One of the ...
3
votes
1answer
234 views

How can I silence ssh-agent?

I have a script like this one at my .bashrc file at the mysuer home: eval `ssh-agent` ssh-add /path/to/my/key The problem is I have this output when I log with the user mysuer (su - myuser): Agent ...
1
vote
2answers
242 views

How to decrease ps aux output to a few lines?

When my computer is slowing down, I usually run ps aux --sort -rss to find out which process consumes too much memory. There may be a lot of processes. How to see only a few ones?
1
vote
1answer
97 views

Unsure about the behaviour of my script when writing to log file

I have a very simple ksh script and at certain points I want to write to a log file. I use the following commands in two places... print "Directory listing 1:\n" > ${LogFile} ll >> ...
2
votes
2answers
116 views

Using Diff with -y to get side-by-side output

I am trying to use diff with -y to get side-by-side output, but my output gets messed up after about 18 lines. Here is an example, any clue why? (Check from *.java_pool_size=134217728) : ...
1
vote
2answers
103 views

How can I see output from a command progressively?

I have fired an ls -1 command that runs and displays a long list of values. When the command ends I can not see the output which is outside the screen vertical length. How can I see those previous ...