Questions about shell scripts, executable files that are interpreted by a shell (bash, zsh, etc.).

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2
votes
1answer
62 views

How to terminate a shell script?

I'm working on a supercomputer and have a shell script that will automatically schedule a bunch of jobs for me. Once the script is run, I can terminate manually with Ctrl+C. I was running the script ...
2
votes
3answers
156 views

sed + remove the first directory from path

Please advise on how to remove the first directory from a path by sed, (the inverse pf what basename does). For example echo "/mnt/VPfig/Amer/AR4/Celtel/files/COM.txt" | sed ... I should get: ...
2
votes
3answers
79 views

adding list of users to multiple groups

I have a shell script which add list of users which is listed in another file lets say users.txt. After that, I want my script to add users to multiple existing groups with condition, one user may ...
3
votes
2answers
56 views

Creating Menu list and Executing the Task

I was given the the Task to create a menu in Linux but it appears it's not coming out great. When I select something I want to be able to perform that task then go back to the main menu when I finish. ...
1
vote
1answer
34 views

how to use the eval command in order to print the value of parameter

Please advice how to use the eval command in order to print the parameter value for example bash a=1 b=2 c=3 for i in ` echo a b c ` > do > echo "$i=` eval $i ` " > done bash: a: ...
0
votes
4answers
48 views

Bash one liner to change configuration parameters

I have a config file with following structure. ValueOne = 1 ValueTwo = 2 ValueThree = 3 I want a one liner bash script to find ValueTwo and change the value to 22222. Any idea? Not School Thing
1
vote
4answers
87 views

Compare two numbers read from a file

I have a script that reads a file with a standard format where the 9th word is a number. I am trying to compare the number that is read from the file. I am able to read the line correctly and it works ...
5
votes
4answers
594 views

generate consistent machine unique ID

Can we generate a unique id for each PC, something like uuuidgen, but it will never change unless there are hardware changes? I was thinking about merging CPUID and MACADDR and hash them to generate ...
0
votes
1answer
82 views

Parse lines of output from bash loop

I'm trying to parse the output of commands run in a bash loop. Here is an example: $ for i in `git log --format='%H'`; do echo $i ; git branch --contains $i; done | head -n 8 ...
5
votes
1answer
607 views

Why do I have to escape a “dot” twice?

I know that we can escape a special character like *(){}$ with \ so as to be considered literals. For example \* or \$ But in case of . I have to do it twice, like \\. otherwise it is considered ...
5
votes
1answer
433 views

sudo: unable to execute ./script.sh: no such file or directory

I'm stumped. I have a script in my /home directory which is executable: [user@server ~]$ ll total 4 -rwx------ 1 user user 2608 Jul 15 18:23 qa.sh However, when I attempt to run it with sudo it ...
0
votes
1answer
26 views

How to dynamically chose PBS queue during job submission

I run a lot of small computing jobs in remote cluster where job submission is managed by PBS. Normally in a PBS (bash) script I specify the queue that I would like to submit the job through the ...
2
votes
0answers
99 views

Securing a script a little more

I currently have the following script which works fine: #!/bin/sh user="$(zenity --entry --title="Username" --text="Username")" pass="$(zenity --password --title="Password" --text="Password")" ...
0
votes
1answer
32 views

Reusing user input in a script

I have the following script which works: #!/bin/bash xfreerdp /cert-ignore /f /v:farm.company.com /d:company.com /g:rds.company.com /u:$(zenity --entry --title="Username" --text="Username") ...
0
votes
1answer
190 views

Bash script question - skip enter key press [duplicate]

Here is a portion of my script: read main_menu case "$main_menu" in "0" ) exit ;; "1" ) cp /etc/bamt/cgminer.conf.X11 /etc/bamt/cgminer.conf; sudo mine restart; ...
1
vote
1answer
40 views

Bundling of dependencies with shell scripts

Shell scripts often have to depend on tools that may not be installed on the users' computer. To circumvent this problem, many scripts have multiple fallbacks. IMO doing such things only leads to ...
3
votes
1answer
71 views

Convert json numbers to strings in the shell

When parsing json, the command-line tool jshon converts numbers to scientific notation, and sometimes tries to round them. To avoid these problems, I want jshon to consider these numbers as strings. ...
2
votes
1answer
112 views

Bash Script Permission denied & Bad Interpreter

I'm on a kali linux 64 bit. I have created a python script which takes 2 arguments to start. I don't want to type out every time the exact same paths or search in the history of the commands I used ...
2
votes
2answers
119 views

How to force watch to run under bash

The problem is that when watch is executed it runs sh and I get this error: sh: 1: func1: not found here is the code: #!/bin/bash func1(){ echo $1 } export -f func1 watch func1
5
votes
3answers
218 views

How to extract URIs from files

How can I extract from a certain number of files all the URIs like magnet: file:? I'd like to have one URI per line as the output. I'd like to use bash to achieve this, but any suggestion is welcome. ...
4
votes
5answers
400 views

Delete the last character of a string using string manipulation in shell script

I would like to delete the last character of a string, I tried this little script : #! /bin/sh t="lkj" t=${t:-2} echo $t but it prints "lkj", what I am doing wrong? Thank you in advance!
3
votes
3answers
148 views

Pipe in a shell script

I have done this little script : #! /bin/sh path="foo" while touch $path ; do path=./${path} done echo "echec avec le nom $path qui fait" echo $path|wc -c echo "caracteres" How can I ...
2
votes
1answer
71 views

SSH config file + shell script help

Well, what I want to do seems a bit convoluted but its the only way I can think of to get the result I want. So here goes. I want to automate ssh to my Pi, in the following fashion: My Pi boots up ...
1
vote
0answers
8 views

Automating minisat solutions

I'm a unix noob and need a simple (bash) script. I am solving SAT instances using minisat. The syntax is minisat inputfile outputfile. However, it only returns one solution. To find all solutions I ...
4
votes
1answer
83 views

Communicating from bash with grunt shell

I'm tired of the slow startup time of hadoop fs just to query HDFS. This isn't a problem with HDFS itself though, because using HDFS file system commands within the Pig "grunt shell" is pretty fast. ...
0
votes
2answers
110 views

If UID=1000 continues, else exit

I am wondering how to implement the following in a bash script. if UID=1000, continue else exit confirm choice (y/n)
0
votes
1answer
41 views

elif [ “$input” = “no” ]; then go the next statement

#!/bin/bash input="" echo "Does a wall needs to be sent?" read input if [ "$input" = "yes" ]; then echo "Sending message to all user about a system reboot or shutdown"|wall elif [ "$input" = ...
0
votes
1answer
56 views

Syntax error in bash script: near unexpected token `else' [closed]

#!/bin/bash input="" echo "Does a wall needs to be sent?" read input if [ $input="yes" ]; then echo "Sending message to all users" echo "" else if [ $input="no"]; then exit fi fi echo ...
3
votes
2answers
50 views

Filtering images according to file name, why?

When filtering the images using the below code, I also need to filter files. For example,IMG_0079.JPG.JPG, when running the code below it's allowing files with additional .JPG to get filtered out, ...
3
votes
3answers
73 views

Moving latest files from one directory to another

I'm trying to move newest files from one directory to another directory. The find command finds the files but not moving them to another directory. The destination directory exists. $ cd ...
2
votes
1answer
97 views

Why does this script work on Ubuntu, and not Debian?

I run a simple minecraft server. I made a script awhile ago for Ubuntu that would automatically create a Gnu screen and start said server. I decided get a new server with debian instead. Now for some ...
3
votes
2answers
36 views

Comparing an string by value of a floating number to a number

I wrote the code below: for j in `cat output_10.txt` do dri=`echo $j |cut -d':' -f1` nu=`echo $j |cut -d':' -f2` tot=`echo $j |cut -d':' -f3` fre=`echo $j |cut -d':' -f4` if [ $fre > 2 ] ...
1
vote
1answer
28 views

How to slice a text file into several files of 100 lines each? [duplicate]

My question might be quite unclear here. I have a giant text file with values that looks like this 0.00601233 0.000139403 0.000133679 0.000139497 0.000141683 0.000141888 0.000138646 0.000133465 ...
3
votes
1answer
53 views

Why does the read command not take interactive options when run by sh?

I want to download a provisioning script that reads some configuration parameters via read, and execute it: curl http://example.com/provisioning.sh | sh The problem is, that the read command in the ...
3
votes
2answers
157 views

using “ifne” in Bash pipe

In my script, I am using the ifne utility from the moreutils package. The line can be simplified to the following: printf "asdf\n" | ifne cat - && echo "stream not empty" ifne only ...
3
votes
2answers
117 views

Can we find page count of a file in Unix/Linux?

I want to count number of pages in the file /var/log/messages, so that I can use pr command to start printing from the page I want to. For example, suppose that /var/log/messages file contains 300 ...
1
vote
0answers
14 views

FFMPEG stream won't show up on Justin.tv

INRES="1366x768" # input resolution OUTRES="1366x768" # Output resolution FPS="35" ...
2
votes
1answer
55 views

Controlling bash script concurrency, flock inheritance

I have a bash deployment script that handles deploying updated code to a Tomcat instance on CentOS, however, both Chef and RunDeck may invoke the script, and since Chef runs periodically there is a ...
2
votes
2answers
38 views

Merging files by rows

Is it possible to copy the whole rows of File1 in a new File3 following the instruction given by File2 by using a simple bash script using sed or awk? File1: /*two or more columns*/ AC 456324 DC ...
2
votes
1answer
115 views

merge csv files by first column

I have 3 csv files like this. csv 1: 1,aaaa,bbb,2014-04-01 2,qwe,rty,2014-04-03 3,zxc,cvb,2014-04-05 csv 2: 2,j,k,2014-04-01 3,a,s,2014-04-04 5,g,h,2014-04-08 csv 3: 2,a,s,d,f,g,2014-04-01 ...
2
votes
1answer
78 views

setenv not working in tcsh

I am trying to install a program on my brand-new CentOs. The installation requires setenv, which apparently does not work, not even in the tcsh shell. Can anyone give me some advice? [Anna@anna ...
1
vote
1answer
81 views

bash: syntax error near unexpected token `('

I am trying to concatenate some files side by side. I use the pr command in the terminal. It works well, but when I use it in a shell script, I get the following error message: syntax error near ...
1
vote
0answers
58 views

Sourcing nested sourced bash script multiple times causes an infinite loop [closed]

I have a cronjob that sources a configuration file, so as to put some variables in the environment, and then runs a script. This config script sources another more general config file that sources ...
3
votes
1answer
20 views

How to execute as the logged-in user in a sudo script (OSX)?

Is there a way to switch contexts like that? The script in my specific case is an installer postinstall script, which requires sudo privileges only for some of the tasks and requires the logged-in ...
0
votes
1answer
46 views

Converting windows date logic into Unix [closed]

I had coded the below logic in Windows batch scripting and I need to replicate the same in Unix. # Calculating Yesterday's Date for /F "tokens=1-4 delims=/- " %%a in ('date/T') do set DY=%%c for ...
1
vote
2answers
75 views

SCP Automation in production environment [duplicate]

I want to implement the use of scp command in a production environment. I don't want to provide my password in the automation script. Is there any way? I need step by step solution.
1
vote
3answers
60 views

what does the -z flag mean here

What does the -z flag mean in the code below: if [ -z $TEST_PARAM ]; then And is there a list of such flags? For a flag like ls -l, I know where to find it, but for a single flag, I didn't get any ...
4
votes
4answers
280 views

what does $* mean in shell [duplicate]

What does $* mean in shell? I have code two function, run_command and run_test, they are called like this: if [ -n "`echo ${GOAT_COMMANDS} | grep $1`" ]; then run_command $* else run_test $* fi ...
2
votes
1answer
48 views

Using xargs with git

I am trying to practice using xargs. I tried the following, passing the SHA1 via xargs: $ git show SHA1 --name-only I also tried: $ git log --author=jim --grep="patch" |head -n 1|cut -d ' ' ...
5
votes
1answer
178 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 ...