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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1answer
21 views

Start sh in a specified directory from inittab

I am currently working on an embedded Linux system. For it to be similar to our other products I need to have it start a shell in a specified directory on boot, accessible using the serial port. For ...
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0answers
13 views
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0answers
21 views

How to source a config file without print the results out?

In the past, I'm using bash consistently, because it's everywhere. But recently I'd like to try zsh, and don't want to give up updating my .bashrc file( It was rsync to all my servers). So, in my ...
2
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2answers
31 views

What's the appropriate way to do “mv ./* ./subdirdir/”?

Under the current directory I have a number of files, and one directory. I would like to move all files to the sub directory: mv ./* subdir/ cannot move ./subdir to a subdirectory of itself... The ...
2
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1answer
16 views

Running make for LFS complains about [ and about missing gawk

I'm having a strange error when I'm trying to start the make process for LFS using the LiveCD SVN Trunk. When I go to run make it gives me; $ make /bin/sh: 1: [: -ne: unexpected operator -e Missing ...
7
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4answers
765 views

Add a newline into a filename with `mv`

It's a serious question. I test some awk scripts and I need files with a newline in their names. Is it possible to add a newline into a filename with mv? I now, I can do this with touch: touch ...
2
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1answer
62 views

Convert IP Address to Coordinates using database

I have a file which contains IP and I wanted to compare it to Coordinates using a local database (instead of API). I tried following a process and break down to pieces and created scripts referring ...
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0answers
19 views

terminate when user type -1 [on hold]

#!/usr/bin/env bash # Above, get the path to BASH from the envvironment. # Below, you could just set the total mileage here. total_mileage=0 # Below, start from zero and count up for the three ...
1
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1answer
54 views

Extracting trace information using gawk

I am new to awk programming and am using gawk to extract trace information from a mrt file in order to use it further for analysis. I have successfully been able to extract trace information from a ...
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1answer
29 views

shell script not running using crontab

This is my script mboxutil -l > n.txt sed 's/^.*user//' n.txt > n1.txt cat n1.txt | sed 's/^.//' > n2.txt sed 's/\/.*//' n2.txt > dss_list.txt rm -f n.txt rm -f n1.txt rm -f n2.txt sed ...
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3answers
260 views

Should I use a slash at the end of path variables in shell script or not? [on hold]

Today when writing my shell script. A question suddenly comes to my mind. Since cd /target_dir and cd /target_dir/ both works. Should I add a slash at the end of my path variables in a shell script? ...
3
votes
1answer
615 views

KSH styling text based menu using STDERR

Is it possible to format the STDERR in order to have a better looking menu using the select command? I have a simple select select oChoice in $(<tempMenu.menu) ; do case "$oChoice" in ...
9
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1answer
81 views

Update bash history on others terminals on exit of one

I know this question has a similar interpretation, as its asked here keep updating (and duplicated here). But what I'm trying to achieve is a bit different. I don't like the idea of my prompt ...
4
votes
3answers
155 views

awk and newlines in the input data

I want to find files in a directory and identify by their mimetype, not by the extension of the files. I'am using this command to determine the mime type: % find . -type f -print0 | xargs -0 -I{} ...
0
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1answer
40 views

Batch move all files from subdirectories to parent directory, but files have same name

I have many files in sub-directories that I would like to have all moved to the parent directory. Ex: 20150530XXXX/1.jpg 20150530XXXX/2.jpg 20150530XXXX/3.jpg 20150530XXXX/4.jpg 20150531XXXX/1.jpg ...
53
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2answers
1k views

Security implications of forgetting to quote a variable in bash/POSIX shells

If you've been following unix.stackexchange.com for a while, you should hopefully know by now that leaving a variable unquoted in list context (as in echo $var) in Bourne/POSIX shells (zsh being the ...
0
votes
1answer
57 views

route -n gives output “route: fscanf”

If I boot my system and no interface has an IP address I get the above output. However if I give an interface an IP, even if I remove it again, this will disappear. Why does this happen? Is it that ...
1
vote
2answers
128 views

bash completion in Posix mode

I would like to use an interactive Posix bash shell but the autocomplete feature doesn't work. When I type the Tab character it simply prints a tab. The tab completion works only when I'm in a ...
16
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4answers
13k views

Solving “mv: Argument list too long”?

I have a folder with more than a million files that needs sorting, but I cant really do anything because mv outputs this message all the time -bash: /bin/mv: Argument list too long I'm using this ...
1
vote
1answer
37 views

CasperJS and PHP In Cron Job Cannot Open Files, Works Fine When Run Manualy

I recently got a new DigitalOcean LEMP environment with Ubuntu. I tried making an SH script that uses CasperJS to scrape data from an external website to a JSON file, and a PHP script to parse the ...
69
votes
10answers
72k views

How to add a newline to the end of a file?

Using version control systems I get annoyed at the noise when the diff says No newline at end of file. So I was wondering: How to add a newline at the end of a file to get rid off those messages?
0
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2answers
50 views

How do you search ! in man sed?

You cannot search ! directly because it puts process behind. For instance, you cannot search ! in sed man. How can you search ! in man?
0
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1answer
46 views

Issue a command in each directory

I have 3 directories: dir1 contains two subdirs. In every subdir there is a slackbuild. I want to build all slackbuilds, staying in the parent directory. I have tried (cd *;sh *ld) But it only ...
88
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7answers
8k views

Why is cd not a program?

I've always wondered why cd isn't a program, but never managed to find the answer. Anyone know why this is the case?
4
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1answer
7k views

Linux - Sending a command to a screen through a shell script? [duplicate]

I'm trying to figure out how to make a script that will be able to send commands to a screen that will execute within whatever the screen is doing. Is this possible, and if so, how is it done? I've ...
1
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3answers
63 views

locate alias with find

On small systems where there is no locate installed, How would an alias look like that gets the same result as locate? I can imagine find can produce the same output so an alias could look like ...
2
votes
1answer
115 views

Autocomplete issue in bash with equal sign (=)

I am trying to make autocomplete work and wroted a piece of code to demonstrate an issue I faced up: $ cat completion.sh function _completion_command() { compopt +o bashdefault +o default +o ...
2
votes
2answers
48 views

ssh command with quotes

I have an odd error that I have been unable to find anything on this. I wanted to change the user comment with the following command. $ sudo usermod -c "New Comment" user This will work while ...
0
votes
1answer
43 views

Practical usage of “shift” shell builtin command?

I checked the /usr/bin/ssh-copy-id(part of openssh-client package at least under Debian) shell-script and it contains following if-statement: if [ "-i" = "$1" ]; then shift # check if we have 2 ...
5
votes
6answers
473 views

How do I check if a variable exists in bash?

I need to check a variable's existence in an if statement. Something to the effect of: if [ -v $somevar ] then echo "Variable somevar exists!" else echo "Variable somevar does not exist!" ...
1
vote
1answer
38 views

Move files from multiple directories to another system

Let's suppose I have a folders in the source system: AB1, AB2, AB3. And I have the same folder names AB1, AB2, AB3 in the destination system. I want to move AB1 files to AB1 and AB2 files AB2 and ...
4
votes
2answers
40 views

How can I disable bash traces?

For any command that I execute in the terminal a comment like + command appears. For example for ls it shows + ls --color=auto.
4
votes
4answers
918 views

How can I make shell aliases available when shelling out from Vim?

In my .zshrc, I declare some aliases. Eg, which dbstart shows the contents of that alias. If I open vim from that shell, it is a child process. In Vim, I can run shell commands with :! some_command. ...
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2answers
53 views

How do i search for certain sections of a file and then extract only relevant information within that section?

So I have a text file that is a server report and has about 1000 lines of information in it. I'm trying to write a script that can search the report for only certain pieces of information I'm looking ...
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votes
7answers
6k views

How to insert the content of a file into another file before a pattern (marker)?

File1 contents: line1-file1 "1" line2-file1 "2" line3-file1 "3" line4-file1 "4" File2 contents: line1-file2 "25" line2-file2 "24" Pointer-file2 "23" ...
13
votes
3answers
2k views

What are the shell's control and redirection operators?

I often see tutorials online that connect various commands with different symbols. For example: command1 | command2 command1 & command2 command1 || command2 command1 && command2 ...
18
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3answers
573 views

Use of ^ as a shell metacharacter

I wrote a small script today which contained grep -q ^local0 /etc/syslog.conf During review, a coworker suggested that ^local0 be quoted because ^ means "pipe" in the Bourne shell. Surprised by ...
47
votes
6answers
20k views

How to check if a shell is login/interactive/batch

I think I understand the differences between an interactive, a login and a batch shell. See the following links for more help: What is the difference between a 'Login' and an 'Interactive' bash ...
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votes
2answers
39 views

Transform text records using only a “for” loop

I have an input file that is text, consisting of lines that look like: 352|C|PAID|7036|VOICE|01-FEB-12 I need to split each line into fields at the | (vertical bar) characters and output each field ...
0
votes
1answer
52 views

Counting program fails in arithmetic test

having a little trouble with this rather basic script. This script works on Bash in my macbook pro, but not on my Linux Mint desktop, which also uses bash. I can't figure out what's wrong with it, ...
2
votes
3answers
56 views

Execute a shell command upon a click event in a web page

Is there a way to execute a bash command when I click on a text in a browser? The web page is on computer A, the browser is on computer B : I want to execute the code on computer B, e.g hsetroot to ...
7
votes
4answers
53k views

How do I exit or cancel a bad bash command?

I expect to get some flak for this, but I can't find the answer anywhere. It seems like it should be so obvious. Sometimes, when I type a bad command in a bash terminal, the cursor just jumps down to ...
1
vote
2answers
40 views

Unable to store ascii value in a variable

I am trying to convert hex to decimal to ascii and store it in a variable. I am using the following code. HEX=30 DEC=`printf "%d\n" 0x${HEX}` echo "$DEC" ASC=`printf \\$(printf '%03o' $DEC)` echo ...
3
votes
5answers
103 views

How to add column in the beginning of file using perl?

I want a Perl one-liner that checks whether the first fields of an input file is the file's name and, if it isn't, adds the file name as the first column on every line. Example written in shell : ...
0
votes
2answers
27 views

Does kali distro not use /etc/environments file?

I appended a path to /etc/environments file and now it is like so: mindaugas@Kali:~$ cat /etc/environment | tr ":" "\n" PATH="/usr/local/sbin /usr/local/bin /usr/sbin /usr/bin /sbin /bin /sbin" I ...
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votes
1answer
41 views

Copying and relative Home

Your current directory is oxford. Make a copy of the file named outline.doc and place it into the sample_dir directory, using relative pathnames. I've attempted everything. sample_dir1 `-- ...
0
votes
1answer
26 views

Combine curl and base64 into one command?

I'd like to POST the Base64 encoding of a file to a server, combining curl and base64 into one command that I can execute. I've tried the following: curl 'http://localhost:5000/files' -X POST -H ...
14
votes
2answers
11k views

What is the difference between interactive shells, login shells, non-login shell and their use cases? [duplicate]

Possible Duplicate: Difference between Login Shell and Non-Login Shell? I have been looking at /etc/profile. bash.bashrc to see how they are run, and notice that some are executed by ...
66
votes
9answers
21k views

How do I delete a file whose name begins with “-” (hyphen a.k.a. dash or minus)?

How do you remove a file whose filename begins with a dash (hyphen or minus) -? I'm ssh'd into a remote OSX server and I have this file in my directory: tohru:~ $ ls -l total 8 -rw-r--r-- 1 me ...
0
votes
2answers
59 views

Bash script that detects if a file is the correct size

I'm trying to make this bash script dispatch and email when it detects that a certain type of file (files ending in ".gz"), which was last modified 24 hours ago, is below a certain size in a ...