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

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2answers
82 views

Ping a host, check if alive or not, and send result to file via a shell script

To clean out my custom hosts file and remove dead domains on Windows I ping the hosts from domains.txt, and if I get a reply I add that host to result.txt: @echo off >result.txt ( for /f %%i ...
2
votes
2answers
71 views

Create variables and assign values via loop (bash)

Is there a way to create bash variables and assign them values via a loop? Something along the lines of: #!/bin/bash c=0 for file in $( ls ); do var"$c"="$file"; let c=$c+1; done EDIT: ...
0
votes
0answers
18 views

Bash Scripts arguments and G++ static and dynamic library generation [duplicate]

I have a library named matrix.cpp that is used by a program named test.cpp. Now, I want to write a BASH script which takes matrix.h and matrix.cpp as input and generates matrix.a and matrix.so ...
1
vote
1answer
23 views

need a detailed guide to start scripts and applications in xfce4

I am looking for a detailed explanation about where is the right place to start scripts applications during the boot process. It seems there is either confusion or not need for the detail I am looking ...
2
votes
2answers
62 views

Need to obtain Awk output in specific sequence

Data in file: 1234567-5678907 3456789-1234563 3456789-1234567 . . . . n Now I want the output in the below format: 1234567-5678907,3456789-1234563,3456789-1234563....n I have used below command ...
1
vote
1answer
90 views

Bash script won't work on current directory

I'm using Kali linux which is based on Debian and wrote an script to copy some files from where the script is based to a specified directory. But when I execute my script (called CopyFiles.sh), cp ...
2
votes
3answers
74 views

Command line options with argument in shell script

I have a script to get ldap user name, email and mobile number: #!/bin/bash echo -n "Enter Unix id > " read UNIXID ldapsearch -x "(cn=$UNIXID)" | awk '/givenName/||/mobile/||/mail/' Here is the ...
2
votes
1answer
45 views

ksh/bash Formatting Files through sed by cat file|sed command

I am new to unix platform, (Alternate Approaches can be discussed) I am trying to change the colors of content of a file conditionally. My file is: A B C D Value Value Value Value Value ...
0
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1answer
45 views

insert value from reference file

I have a daily csv file with thousands of rows. I have been asked to concatenate two columns, then insert a new column when a value in a given column matches a table from another file. Empty values ...
4
votes
2answers
197 views

Best and short way to run a program if another is not installed

I have this code: #!/bin/bash num=${1:-undefined} cmd=$(which {banner,echo} | head -n1) until [[ "$num" =~ ^[0-9]+$ ]]; do read -p "Type a number: " num done for ((num;num>=0;num--)); do ...
5
votes
4answers
257 views

Converting `for file in` to `find` so that my script can apply recursively

I've been working on my first bash script for some time now (I just started UNIX this week). I have this idea of running a bash script to check some conditions and using ffmpeg to convert all the ...
0
votes
1answer
50 views

How can I get a shell script to change directory for me? [duplicate]

here is a small test I ran, to try and move me back to root: #!/bin/bash pwd cd / pwd It returns the current working directory, and then the correct new one, but when the script finished executing, ...
1
vote
4answers
43 views

Anyway to pass a variable to bc, having a command to be executed?

I need to pass certain variable to bc to get the output in floating point, var1=$((<some operation>)) var2=$((<some operation>)) #Needs var1 var3=$((<some operation>)) ...
1
vote
2answers
87 views

One-Liner needed: Stop httpd if running already & Start httpd if not running

As part of a provisioning script for CentOS 7 I am in need to have a one-liner that performs the following. Unfortunately, I have no clue how to achieve that. If httpd is running then stop it If ...
0
votes
1answer
77 views

How to get rid of “\r” a the end of the line comming from pipeline in bash

#!/bin/bash sourcenode=$1 destnode=$2 path1=/root/test ssh root@"${sourcenode}" -t "echo "${path1}" | xargs -IDIR find DIR " | while read line do ssh root@"${sourcenode}" -t "stat -c "%a" ...
3
votes
2answers
31 views

locally created alias not being used if called using backticks (`)

I have come across this issue while trying to build up a script to do grep on multiple files for 10 different word. The script I created, is (minified) #!bin/bash alias grep='grep -n' out=`grep word ...
0
votes
1answer
40 views

find all directories (except `encoded`) in the working dir then delete all of them

I am trying to test this scenario, I have these files /encoded encode <~~~ a bash script /dir1 /dir2 .../dir2-sub test.meta what I wish is, for find to search for all directories in our current ...
0
votes
1answer
50 views

killing a job running in the background

I have started running a long job by creating a script that executes several commands on 20 or so datasets sequentially. I began in the xterm window with $ script.scr then typed <ctrl-Z> ...
0
votes
2answers
37 views

IPtables errors

I am working on a project. I am trying to write iptables rules to control network traffic. I have written some rules. When I try to apply them to the boxes that I am working on I either get locked ...
0
votes
1answer
49 views

how to write a shell script to run multiple programs

I want to run two programs ssh -f mike@c15-0330-02 'cd /home && nohup Rscript L_1.R> L_1_sh.txt ' AND ssh -f mike@c15-0330-03 'cd /home && nohup Rscript L_2.R> L_2_sh.txt ' I ...
1
vote
1answer
41 views

If statement in shell-script only half-working

I've been trying to write a script to rotate my monitor, I'll then assign it to a keyboard key. I've been fairly successful in making it rotate once, however when I run the script again, it doesn't ...
11
votes
5answers
588 views

Convert underscore to PascalCase, ie UpperCamelCase

If I have a string that looks like this: "this_is_the_string" Inside bash script, I would like to convert it to PascalCase, ie UpperCamelCase to look like this: "ThisIsTheString" I found that ...
3
votes
2answers
81 views

using the variable “file” obtained from `for “file” in` and pass to another script fails [closed]

I am trying search for all .mkv files in my current folder, then using mediainfo I want to put the height from its meta data to a variable, but it seems it is failing. This snippet: ...
0
votes
1answer
27 views

Nnumber of HTML redirects from cURL

My little script extracts DOI's from a csv files in order to check whether they are right. The number should equal 3, and if it doesn't, I want to output an message. #!/bin/bash ...
2
votes
5answers
433 views

Problems when trying to execute sh file from another sh file

I have the following script: #!/bin/bash if test -f "/path/pycharm.sh"; then sh ./pycharm.sh; fi I am trying to run pycharm.sh from a bash file and I've looked carefully to give all the ...
0
votes
1answer
38 views

grep two searched words

I could search lines that contain two specific words using the following in multiple files: for f in $(ls *.txt); do echo ">"$f; more $f | grep word1 | grep word2 done Now, I want to write a ...
2
votes
2answers
132 views

Passing a bash command line arguments containing #

I am trying to pass pound sign as a command line argument then echoing the argument. When I pass for example 2 # 2 then I echo $1 $2 $3, I assume the terminal will output 2 # 2 but it outputs just 2. ...
3
votes
3answers
143 views

Bash script command line argument to upper case

If I can do this in my bash shell: $ STRING="A String" $ echo ${STRING^^} A STRING How can I change my command line argument to upper case? I tried: GUARD=${1^^} This line produces Bad ...
0
votes
2answers
37 views

Auto Delete Inactive files after x

Is there a way I could delete certain folders after x amount of days of inactivity? I was thinking of using cron but that wouldn't take the inactivity part into consideration. Is there any Debian ...
1
vote
2answers
45 views

I cannot understand bash script results

Here is the script: echo '1 2 3 4 5 6' | while read a b c ;do echo result: $c $b $a; done The result is 3 4 5 6 2 1 Can someone explain why?
0
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0answers
19 views

check media resolution if resolution is big ffmpeg it, if output is smaller than original delete the original else delete the output

I have my storage VPS filled with videos, and hoping I can free up some space, their resolution is pretty big so I decided to re encode them with ffmpeg to a smaller resolution, I am doing every thing ...
0
votes
1answer
38 views

How to terminate cat command within a shell script

I wrote a shell script that uses cat and tr commands to generate a file. My shell script looks like #!/bin/bash printf "generating random file > plaintext \n" cat -v | tr "a-z" "b-y" < ...
1
vote
3answers
131 views

Bash long string, no word splitting?

I want to tidy up some script with long commands, so that for example: { somecheck || somecomand "reallyreallyreallyreallyreallyreallylongstring" } &> /dev/null & becomes something like: ...
1
vote
2answers
57 views

How do I make a BASH loop

I'm very new to bash and Linux and I was wondering how I could make a bash loop so that when it runs, it will ask you how many times to run, and it will run that many times. I did it in LUA but I ...
0
votes
0answers
47 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
245 views

How to find a specific 'string' and print out the whole line?

I have a file named myfile.csv containing the following: abc:123:myname:1231 def:423324:arbitrary:value:string StackExchange:Unix:Linux From the terminal I run ./myscript.sh def The contents of ...
1
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2answers
65 views

Using command substitution

The shell variable number contains 1 1 1 1 1 separated by tabs. I want it to contain only the first 1. I'm trying number= $(echo "$number"| cut -f 3 ) and I get the error "1: ...
2
votes
3answers
70 views

How do I remove the extra 'garbage' from this logfile?

I'm having some issues with log files from IIS 8.5 which I want to process with AWstats. Since my IIS servers are behind a load balancer I had to add a custom logging field, X-FORWARDED-FOR. However, ...
1
vote
1answer
133 views

Sed command that would ignore any commented match

I'm trying to create a sed command using regex in order to substitute something in a text file only if it is not commented but I'm running into some troubles due to my almost non-existent knowledge of ...
-1
votes
1answer
24 views

How to make a process wait in the background and be able to be killed by signal other than KILL

I want a script run in the background, take some actions for every hour. It should also quit if receiving a signal. And at last, it should perform some clean-up actions before quitting. Based on the ...
1
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2answers
42 views

Background processes mix up order of shell script execution

Can someone explain me why the script echo one && echo two & echo three && echo four gives me [1] 3692 three four one two [1]+ Done echo one && ...
0
votes
0answers
24 views

Is there a way to add a timestamp to the logs for qsub job?

I'm submitting jobs on a cluster via qsub but the error/output logs don't have a timestamp, making debugging more difficult. Is there a way to add timestamps to the logs in the bash script? Appreciate ...
0
votes
3answers
102 views

How do I copy the latest file from one directory to another?

I have 3 zip files in a directory. I want to copy the most recent version to a backup directory. My code works fine for .sh and other files, but not for .zip. Is there something else I have to do? ...
14
votes
9answers
512 views

Filter or pipe certain sections of a file

I have an input file with some sections the are demarcated with start and end tags, for example: line A line B @@inline-code-start line X line Y line Z @@inline-code-end line C line D I want to ...
2
votes
4answers
127 views

How to make diff command ignore certain lines of second file(bash)?

For example: file1.txt: I need to buy apples. I need to run the laundry. I need to wash the dog. I need to get the car detailed. file2.txt I need to buy apples. I need to run the laundry. I need ...
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votes
1answer
38 views

Cron job * is replaced by file name in current directory [duplicate]

This is my first shell script program, so i think this is more likely a silly question for you all. Overview of problem My need is to write a shell command for installing our Node.js server. ...
2
votes
3answers
246 views

KSH/BASH Maximum size of an Array

What is the maximum size of array for ksh and bash scripting ? Example: Suppose I have an array of 10 elements than what will be maximum number of string count that a particular index of an array can ...
0
votes
1answer
82 views

Bash detect ascii art [closed]

For bash script, is there a easy way to detect if a text contains ascii art? An example of ascii art:
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votes
1answer
45 views

Replace mutiple strings with different values in a file using unix [duplicate]

I have a file in which the data is like below, 01,0000000,xxxxxxx/ 02,xxxxxxxx,yyyyyy/ 03,test1,41203016,,/ 01,0000000,xxxxxxx/ ...
0
votes
2answers
39 views

recording total runtime in bash script

I have the following script. When it runs it prints the Start and end Times to the file 'result.txt'. However, I also want to record the total runtime (end-start), but where I am doing echo runtine ...