The shell is unix's command-line interface. You can type commands in a shell interactively, or write scripts to automate tasks. Use this tag for questions applying to /bin/sh and most compatible shells (ash, bash, ksh, zsh, …).

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meaning of !(something) in shell [duplicate]

While searching for a way to move all files in a dir to one of its sub-folders, i came across mv !(something) something which should do the job - but only in bash. However i could not find why. in ...
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1answer
47 views

Combining strings command and grep: how to limit results to null-terminated strings

I have a feeling that it is strings which is thwarting my efforts here. The binary files I want to use strings on unfortunately yield several matches per file, even though it is a 100% rule that ...
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2answers
42 views

how to login a user using shell script [on hold]

In my computer i have two user(tiger,jenk) now i want to create a shell script for login user "jenk" from user "tiger" i m try this code [tiger@pagaltiger mytask]$ echo -e "IncorrectPassword\n" | ...
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1answer
35 views

Only send email if disk usages exceeds 80%

My script is: abc=$(df -h | sed s/%//g | awk '{ if($5 > 80) print "Alert "$0;}' | awk '{print $2,$6}') \ && echo -e "Dear All, \n\n$abc\n\nABC" \ | mailx -s "Disk partition" ...
2
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1answer
21 views

Get current memory usage of a tmux session

As the title says. I need a way to the used memory of a current tmux session. I am not sure if that is even possible. I am using tmux to start multiple minecraft servers I'd like to know each servers ...
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3answers
66 views

To calculate average by taking command line argument

The task is that if input numbers: 4 1 2 9 8 Output=(sum of all except first_number_in_series)/first_number in series Then output average should be 1+2+9+8/(first_number_in series)=20/4=5 I have ...
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2answers
41 views

How do I permanently remove an Alias from my Shell

When I was not near my computer some guy got it and set an Alias for ls in my root folder. He set it to 'yes NeverGonnaGiveYouUp'. So now when im in my root folder and type ls I get an infinite loop ...
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3answers
39 views

Can the Bash shell “Ignore” Excess copy-paste text?

Say, I have a "Quick&Dirty" Perl script in a gui text editor, and I start the Perl interpreter in a terminal window which is running Bash. I can copy-paste the Perl script to the terminal & ...
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5answers
10k views

How can I kill and wait for background processes to finish in a shell script when I Ctrl+C it?

I'm trying to set up a shell script so that it runs background processes, and when I Ctrlc the shell script, it kills the children, then exits. The best that I've managed to come up with is this. It ...
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2answers
35 views

Which location does shell assign normal variable?

As you know, bash shell itself is also process. If I use command export a=c, then shell dynamically allocates variable a into location where environment variables are reside.(This environment section ...
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3answers
974 views

Escape sequences in output of script called from ncurses application

I'm currently running mcabber as my Jabber client (which uses ncurses) in a tmux session on my homeserver. Locally i run iTerm2 as a terminal emulator, which supports the triggering of growl ...
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1answer
30 views

Kill command also kills other process

I have a very simple script, let's call it foo.sh. It's this: #!/bin/sh sxhkd & panel & where panel is a script (I won't post it here because it's very long and I don't think it would be ...
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5answers
338 views

How can I find the first missing directory in a long path?

Imagine I have a path that doesn't exist: $ ls /foo/bar/baz/hello/world ls: cannot access /foo/bar/baz/hello/world: No such file or directory But let's say /foo/bar does exist. Is there a quick way ...
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2answers
795 views

Use a script for a telnet session

I have a problem with my script. It seems my password is wrong. #!/usr/bin/expect set ip [lindex $argv 0] spawn telnet $ip set timeout 10 expect "Login:" send "administrator\r" expect "Password:" ...
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1answer
55 views

Are there non-interactive login shells?

I know what the difference between interactive/non-interactive and login/non-login shells are, but it seems like in practice there's never going to be a non-interactive login shell unless you have ...
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3answers
30 views

How do I organize and cut this portion of a directory into a file?

I'm new to unix and I'm not sure how to name my title but my main objective is to copy the contents of a directory and send it to a file. Then cut out the directory location to just have the name. ...
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1answer
40 views

Unexpected end of file in .bash_profile

When I do source ~/.bash_profile I get this "line 14 syntax error: unexpected end of file" error, I tried to delete the last line for no avail. Thanks # Get the aliases and functions if [ -f ...
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3answers
403 views

Why is 'ls' suddenly surrounding items with spaces in single quotes?

I just noticed that on one of my machines (running Debian Sid) whenever I type ls any file name with spaces has single quotes surrounding it. I immediately checked my aliases, only to find them ...
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2answers
20 views

bash adding a filename to an alias command [duplicate]

I have an alias to a ffmpeg command to start recording a session like this: alias sreq='ffmpeg -f x11grab -r 24 -s 1024x768 -i :0.0 -qp 0 -c:v libx264 -preset veryslow' I can just type sreq ...
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0answers
18 views

Removing intermediate line breaks in muliple columns except the last new line character [closed]

Suppose If I have the data like this Col1|Col2|Col3 <br\> 123|abc\n<br\> xyz\n<br\> |abc\n<br\> def\n<br\> other rows<br\> <br\> In the above newline ...
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0answers
31 views

How to get curl progress bar in terminal?

I'm using curl to upload files from a bash shell. I know there's the option --progress-bar which is supposed to give an upload progress indicator, but no matter what, I can't get it to show. I do ...
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2answers
101 views

Why does the cd command handle STDIN different than other commands?

Commands like cd cannot have output piped to them in order to change directories--they require command-line arguments. Why does the cd command (and those similar to it, such as mv, cp, & rm) not ...
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4answers
14k views

Remove ^M character from log files

Remove ^M character from log files. In my script I redirect output of my program to a log file. The output of my log file contains some ^M (newline) characters. I need to remove them while running ...
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0answers
50 views

Some commands are no longer responding?

I have a Debian based distribution & lately a problem has been encountered when trying to execute the gcc or man command's (And probably other commands I haven't found yet). When I type them in ...
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4answers
415 views

Calculate date difference between Last modified date of a file and NOW using shell script

I am trying to calculate the time elapsed since the log file was last updated. I guess following commands will be used lastUpdate=$(date -r myLogFile.log) now=$(date) How can I subtract them and ...
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2answers
1k views

Replace a substring of filenames in a directory

There exists a directory, which includes several levels of sub-directories. Under these directories, there are a set of files whose names include a common word, e.g, .cc. How can I replace the .cc ...
9
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3answers
1k views

Writing a character N times using the printf command

I found the following command to repeat a character in Linux: printf 'H%.0s' {1..5000} > H.txt I want, for example, H to repeat 5000 times. What does %.0s mean here?
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1answer
41 views

Kill a running shell script, and kill all process running within it

I have a shell script running in the background, which runs 5 different jobs. When I run the shell script all 5 jobs start running in order. When I kill this shell, whichever process is running, will ...
1
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1answer
27 views

Can Bash tell an interactive SSH session from an in-line SSH session?

I have a Bash script that needs to be run from an interactive prompt, due to environment variables and configuration that only seems to be read when actually logged into a session. Examples below: ...
2
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1answer
56 views

Something confusing about “su -” and “su” [duplicate]

I am studying the Linux command line. But the book which I'm reading says that su -l(-) username is starting a new shell session and loading the environment of the user I want to change to, but su ...
1
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1answer
46 views

bash - queue subshells

function _abc { : 1 min task : _check & } function _check { wait for the previous calls of _check to complete : 15 mins task : } function abc loops depending on number of tasks. It is ...
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3answers
4k views

Skip first 3 byte of a file

I am using AIX 6.1 ksh shell I want to use one liner to do something like this cat A_FILE | skip-first-3-bytes-of-the-file I want to skip the first 3 bytes of the first line, is there a way to ...
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3answers
323 views

How to sleep until a given date & time?

I want to write a shell where given a date (day-hour-min) e.g. 10:00 AM Sun 2:30 PM Mon ... It sleeps until that exact date & time. I thought one way of doing it is, I could get the current ...
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2answers
51 views

Unable to run a process on background

I need help with a Solaris system. I have used the following command to run the cp.sh script in the background. nohup sh cp.sh < /dev/null & > /dev/null & output: Invalid null ...
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2answers
21 views

shell command wrapper for socat

I have used the command socat - foo The text I type is sent directly to address foo. Is there some general-purpose wrapper for stdin (along the lines of ! from ed) that lets one parse a shell ...
1
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1answer
44 views

generate file names in loop [closed]

DISCLAIMER: I am using Mac OSX. The bash script is in a different directory from the files that require processing. From here my struggle begins… HELP 1: I have multiple files each housed in a ...
10
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3answers
14k views

How do I insert a space every four characters in a long line?

I've got a long line that I want to insert a space every 4 characters, on a single lone line of solid text to make it easier to read, what's the simplest way to do this? also I should be able to input ...
0
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1answer
2k views

How to execute Netscaler commands through a remote machine via SSH connection

I have been trying to execute some NetScaler commands like "bind" & "unbind" through a Linux Box via an SSH Connection. Now the Problem is, Manually we are able to enter & execute commands on ...
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3answers
2k views

The best way to add Unix Shell variables to CURL GET request

Let’s say I use curl –X GET command with the following link: “$WEBSITE_URL/ACTION_NAME/ACTION1;id=$ID?Command=TEST&id1=$ID1&id2=$ID2&id3=$ID3” As you can see, there are some $variables ...
1
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1answer
25 views

Cron Job Hourly Except Certain Time Frame on Friday

I want my cron job to run every hour, every day except Friday when I don't want it to run at all between the hours of 2am-9am (but hourly outside of this timeframe). Ideally, I'd like to have this in ...
3
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4answers
663 views

How can I turn the behavior of `gedit something & disown` into the default behavior when calling gedit from the command line?

When I gedit files from the command line, it's always locking the terminal, and I'm tired of explicitly commanding a detached process for it. I tried to alias gedit as something like gedit $* & ...
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0answers
701 views

Detach a process from Sh (not Bash) or “disown” for Sh (not Bash)

Consider a shell script executed by Sh, not Bash (and I can't change it, and can't use a shebang, it's ignored). The & operator works, but disown $! does not and makes Sh complains “disown: not ...
0
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2answers
32 views

How to seperate executable calls as different functions in shell script?

This is what I would like to achieve. #!/bin/bash function startBasics() { gnome-terminal -e "sth" & gnome-terminal --tab -e "sth_else" & } function doOneThing() { ...
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0answers
38 views

Bash script is not executing after reboot command Ubuntu 14.04

I've tried using a /etc/init.d/ script, an upstart script, crontab, etc. None of the above are causing the script to execute on boot. The service I am attempting to automatically start on boot is ...
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3answers
21k views

Recovered deleted files on Mac by command line

I accidentally deleted a file by running: rm -rf ./Desktop/myScript.sh I think it's possible to recover the file, because the rm command removes temporarily. How can I recover the deleted file on ...
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2answers
14k views

How are parentheses interpreted at the command line?

While reading up on how to set up grub, I came across an article claiming that I need to use one of the following two syntaxes, echo \(hd0,0\) >> /boot/grub/grub.conf or echo '(hd0,0)' ...
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0answers
17 views

ssh -f, running remote startkde, does not exit. Why?

I hope that someone already knows the answer to this, because I fear that trying to unravel the startkde shell script, and the subtleties of ssh -f is going to be ugly. I am opening a remote desktop ...
0
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1answer
32 views

Why can't my Unix terminal not find my matlab binaries and making Unix find them again?

This happens to be a new problem because I was able to run MATLAB on the shell until today. I didn't install or update it or anything of that sort, but now I am unable run matlab in the sell. It tells ...
2
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1answer
54 views

How to add my MATLAB to PATH?

I have read this thread on how to correctly add the paths: How to correctly add a path to PATH? I have already exported path ...
3
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1answer
971 views

Compare file size of multiple files in an array [closed]

Scenario: Ftp site has 100s of files. Once a day, all the .gz files are copied to an AWS site then renamed. Only the date is kept in the file name. Some of the files corrupted during copy. A txt ...