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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0
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1answer
50 views

List hidden files only (not just dot files) using an ls alias

I would like to use an ls alias (like l.) to output a colored list, consisting of only hidden files & directories, whether or not they begin with a dot. Any suggestions? Example of desired ...
11
votes
3answers
1k 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 ...
0
votes
0answers
41 views

Testing Remote SMTP Server Port

I am currently working in a lab environment to test a script for my production environment. My environment has several remote firewalls, all of which have an external mail Virtual IP (VIP). Our ...
0
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0answers
12 views

Long response time when using chroot

I have a Ubuntu 14.04 LTS Server and yesterday the response time of the server was quite long, meaning when using simple commands like: ls -al it would take up to 20 seconds to respond in a very ...
55
votes
9answers
140k views

How to overwrite target files with mv?

I have a ton of files and dirs in a subdirectory I want to move to the parent directory. There are already some files and dirs in the target directory which need to be overwritten. Files that are only ...
0
votes
1answer
37 views

Why this script didn't work? [closed]

#!/bin/bash if [ $# !=1 ] then echo Usage: A single argument which is the directory to backup exit fi if [ ! -d ~/projects/$1 ] then echo 'The given directory does not seem to exist (possible ...
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votes
12answers
3k views

What's a good way to filter a text file to remove empty lines?

I have a .csv file (on a mac) that has a bunch of empty lines, e.g.: "1", "2", "lorem ipsum lorem ipsum lorem ipsum lorem ipsum lorem ipsum lorem ipsum lorem ipsum lorem ipsum lorem ipsum lorem ipsum ...
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votes
2answers
5k views

What's the difference between “realpath” and “readlink -f”

I've read a lot about realpath command and how it has been deprecated with the readlink -f being now recommended. I have also seen in some places that the reason why realpath was introduced was for ...
64
votes
11answers
76k views

How do I convert an epoch timestamp to a human readable format on the cli?

How do I convert an epoch timestamp to a human readable format on the cli? I think there's a way to do it with date but the syntax eludes me (other ways welcome).
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votes
3answers
45 views

How to swap two words with sed and with multiple delimiters?

Just letters are accepted in words, any other characters are delimiters. I want to exchange the first word with the third word. sed -E 's/([A-Za-z]+) [^A-Za-z] ([A-Za-z]+) [^A-Za-z] ([A-Za-z]+)/\3 \2 ...
0
votes
2answers
26 views

Does cp -a refresh existing files, overwrite or skip

If I use cp in archive mode e.g cp -a /my_old_directory/* /new_location/my_new_directory/ to replicate a directory structure and all that is in it. If I then run the same command again will any ...
130
votes
15answers
52k views

Get exit status of process that's piped to another

I have two processes foo and bar, connected with a pipe: $ foo | bar bar always exits 0; I'm interested in the exit code of foo. Is there any way to get at it?
0
votes
1answer
2k views

Any possibility to execute shell script from java file?

I have one Java file named app.java which extracts the servers in my application. I need to connect to every server in that list and extract the logs. In loop, I have to call script for connecting to ...
0
votes
3answers
3k 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 ...
9
votes
4answers
407 views

Keeping history per working directory (cf. per shell session)

Is there a way to make a modern shell's history feature be scoped to a path? My working contexts are split up as paths on the file system, and the pattern of shell activity, such as repeatedly issued ...
0
votes
1answer
38 views

Setting up aliases with interactive ssh session [duplicate]

I need to keep ssh'ing into many-different Linux boxes (Ubuntu mostly) and every time I miss my basic aliases. Is there a way to setup aliases etc while opening an interactive ssh a machine without ...
0
votes
1answer
26 views

I moved a new program into my bin folder, but nothing happens when I try to run it [closed]

I have two identical files in my ~/bin folder, test and test2. Both just print a string. One works; the other, which I just put in there today, doesn't. In fact nothing happens at all, which is odd. ...
0
votes
2answers
1k 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:" ...
3
votes
3answers
18k views

How to change the working directory for a shell script

I have a Python script that looks files up in a relative directory. For example: the Python script is in /home/username/projectname/. I have a file that is being called within the Python script that ...
91
votes
6answers
8k views

Run a command that is shadowed by an alias

Let's say i have the following alias in bash - alias ls='ls --color=auto' - and i want to call ordinary ls without options. Is the only way to do that is to unalias, do the command and then alias ...
0
votes
1answer
41 views

Why does 'find -mtime +1' include today's files when used in a script? [closed]

I'm using the following find command in a script: find . -type f -mtime +1 When I use it from an interactive shell, this gives only old files, but in the script it also gives today's files. Why? ...
3
votes
3answers
53 views

All files in a directory that do not end in a specific string?

I want to find all text files in a directory that do not end with the string: hello world How can I do this?
0
votes
2answers
41 views

How is redirection implemented?

Is redirection a concept of the shell, not of the OS kernel? How is redirection implemented in terms of system calls? Is redirection implemented similarly to pipe?
1
vote
2answers
338 views

Displaying messages to tty using whiptail through monit

I would like to display a whiptail message on the login screen that is triggered by monit, but I am without luck. I understand it might be something to do with interactive/non-interactive shell. Here ...
1
vote
1answer
909 views

How do you make case statements with ranges

I'm supposed to: Make a case statement that will display the a grade after input. With no loop or conditional. A=90-100, B=80-89, C=70-79, D=60-69, F=0-59 This is what I have so far: ...
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votes
0answers
16 views

shell connection mysql connection appears to be blocked

See mysql master-slave synchronization status. I error occurs in connection with the following shell mysql: $(mysql -h${Mysql_Server} -u${Mysql_Slave_user} -p${Mysql_Slave_passwd} -e 'show slave ...
0
votes
2answers
58 views

Unable to execute bash script inside expect script

i have a expect script like #!/usr/bin/expect ..... spawn passwd expect "password:" send "password" .... .... .... ~/test.sh Wile executing this, I'm unable to run bash script test.sh. How to ...
11
votes
5answers
30k views

Export an env variable to be available at all sub shells, and possible to be modified?

Suppose I have export MY_VAR=0 in ~/.bashrc. I have an opened gnome terminal, and in this terminal, I change $MY_VAR value to 200. So, if I do echo $MY_VAR in this terminal, 200 is shown. Now, ...
9
votes
6answers
45k views

How to use a shell command to only show the first column and last column in a text file?

I need some help to figure out how to use the sed command to only show the first column and last column in a text file. Here is what I have so far for column 1: cat logfile | sed 's/\|/ /'|awk ...
0
votes
2answers
149 views

Printing all lines of a file with multiple columns in a shell script

I have a file with 4 columns with the below format: name;user_id;dob;date_of_joining I want to print all the variables in below output via shell script The employee "$name" is having "$user_id" ...
0
votes
0answers
15 views

useradd failing [duplicate]

Debian 8, I'm trying to allow a user to run Wireshark. user1@system:~$ sudo useradd -G wireshark user11 useradd: user 'user11' already exists However: user11@system:~$ groups user11 cdrom floppy ...
1
vote
1answer
36 views

How to organize files in Linux/Unix shell?

I would like to try to organize my documents, and I was told that I can do this using the linux/unix cygwin terminal. I searched for the command in google but all I ever did find was organizing the ...
1
vote
5answers
14k views

How to copy a file from a remote network to the local desktop

So I used SSH to remotely login to another computer on a network. I have many files that I would like to copy over to my local desktop. I am trying to follow this How-to : However, I think one ...
3
votes
3answers
55 views

How to make two commands consume input from stdin sequentially?

The following perl script consume-10-lines-and-exit reads ten lines from stdin and prints them. After that it exits. #!/usr/bin/env perl use strict; use warnings FATAL => 'all'; for (my $i = 0; ...
3
votes
1answer
37 views

Combining every two column values in file

I have a file with (with only one line) with multiple columns say 4 (in this case) : A B C D And I want the output as every possible combination of column values taking 2 at a time like: AB AC AD ...
0
votes
2answers
37 views

Flow control using Unix shell

I need to do an exercise at the university, its all about reading 3 values and identify if there is any duplicated value, which value is the greatest and which one is the least, the idea is if you ...
1
vote
1answer
28 views

Remove certain types of files except in a folder

I have a command in my makefile for clean: rm -rf */*.o */*.cmo */*.cmi */*.cmx */*.cma */*.cmxa */*.annot Now I would like to write a cleanpartial that removes these files except those in the ...
1
vote
2answers
46 views

Define a variable to awk pattern matching from bash

I am trying to grab 100 lines after the text "time: X" with X in {0,40,80,...,200}. Here is what I have so far: #!/bin/bash start=1 end=5 for i in $(seq $start $end);do j=$(($i*40)) awk '/time: ...
1
vote
0answers
22 views

Passing external parameter to .exe on Windows using winexe from Linux

I am trying to execute a .exe on Windows from Linux using winexe. This exe requires an external parameter (string) to be fed alongwith. With the following command I have succeeded in initialising the ...
1
vote
1answer
35 views

code to display the text TRUE

I'm a complete newbie and I'm starting to learn the basic for shell scripts. So I apologize if this question is very simple for most users. I'm trying to display the text TRUE to the screen if a file ...
2
votes
0answers
43 views

Prevent scp and less commands reading interactive tcsh script

I'm using tsch through PuTTY, and let's start by this: please don't try to convince me to migrate to another shell...:) It's being a long time that commands like scp and less didn't work well for me. ...
3
votes
2answers
88 views

Filter files generated by `find` by parsed output of `file` command

I'm writing a quick tool to inspect the contents of a node.js node_modules folder or python virtualenv for native dependencies. As a quick first approximation to this I wrote the following command. ...
0
votes
0answers
17 views

vim + tmux: some shortcuts broken?

When I am using vim inside of tmux, some of my shortcuts are broken. E.g. I have bound Ctrl + up/down and Shift + up/down in my .vimrc and when I'm running vim inside of tmux these shortcuts do not ...
0
votes
3answers
578 views

Can dash replace bash as my default shell?

From what I read, dash can be made as a shell by using the command ~$ chsh shirish Password: Changing the login shell for shirish Enter the new value, or press ENTER for the default Login Shell ...
0
votes
1answer
32 views

How to insert a string before a matched string

How can I insert a string before a matched string. Suppose I want to insert a string a before "if (PROTOCOL == "https://")" string. Please tell me how can I do this?? or How to search and replace ...
18
votes
4answers
32k views

Why doesn't my ~/.bash_profile work?

I'm using Linux Mint. My login shell (cat /etc/passwd | grep myUserName) is bash. After I start my graphical desktop environment and run terminal emulator from it, I could see that .bash_profile is ...
0
votes
2answers
33 views

Compare and return first instance of n characters from a list

Lets say I have the output of this command saved to a file. cat /dev/urandom | tr -dc '[:graph:]' | fold -w 1000 | perl -pe 's/(.)(?=.*?\1)//g' | head -n 50 I would like to compare only the first n ...
24
votes
2answers
1k views

Opening Your Command Prompt In A Text Editor - What Is This Called?

One of my favorite tricks in Bash is when I open my command prompt in a text editor. I do this (in vi mode) by pressing ESC v. When I do this, whatever is in my command prompt is now displayed in my ...
7
votes
2answers
1k views

Are there problems with hyphens in functions, aliases, and executables?

In my testing (in Bash and Z Shell), I saw no problems with defining functions or aliases or executable shell scripts which have hyphens in the name, but I'm not confident that this will be okay in ...
5
votes
2answers
12k views

Running sh script: «Permission denied» despite the executable bit and root rights

I installed Debian in VirtualBox (for various experiments which usually broke my system) and tried to launch the VirtualBox guest addon script. I logged in as root and tried to launch autorun.sh, but ...