Questions about bash only, as opposed to other Bourne/POSIX shells. For all Bourne/POSIX-style shells, use the /shell tag instead.

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1
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1answer
22 views

How to set Timeout for an ssh command and also get back the result of remote commands

I have a script that runs on bash, in an RHEL server that connects to thousands of nodes and returns with the values of some 5 executed commands - It collects info from RHEL Servers only. It works ...
3
votes
2answers
102 views

Convert all first character in an email id to Upper case in BASH

I need to accept an email id and Full name in a script, and in case the Full name is not provided, I need to generate the name from the email id. Something like this: Case 1: EmailID: ...
-4
votes
0answers
37 views

Check if a file exist or not in a directory or not?

Create a script to indicate whether a named file exists or not in your home directory or any of its subdirectories. It should print out the message "File does not exist" if the user gives a ...
0
votes
1answer
22 views

how to count the length of an array defined in bash?

I'm new to bash and can't find a good tutorial to answer my question. array=( item1 item2 item3) for name in ${array[@]}; do echo current/total ... some other codes done I want to calculate ...
-4
votes
0answers
14 views

BASH— after getopts continues after exit [on hold]

in getopts(probably) it has two functions in it. One of them has exit at the end and there is also exit at the end of the option b. When I call it like this: ./name.sh -b. (without required argument) ...
3
votes
1answer
13 views

vipe misbehaving on bash process substitution

I have the following simple command: $ echo <(vipe) I expected it to open a vim buffer, which I can edit, then when I'm done, echo the name of the temporary file assigned to hold the vim buffer ...
3
votes
1answer
19 views

Moving sub-directory to new parent directory where the new directory name is incremented by 1

I am attempting to move a sub-directory from one parent directory to another for hundreds of instances, while changing the name of the sub-directory during the move. My directories are a set of ...
2
votes
1answer
33 views

what are practical uses of stdbuf or nohup?

I have to finish a writeup of a few coreutils commands for a course at the moment, and I can't think of a starting point for a small practical code example that demonstrates the potential uses of ...
0
votes
1answer
46 views

What does $'text' do exactly in Bash? Can it be used in Zsh?

I recently run into the following proposed solution: cat results.csv | tr $'\x01' \\t > result.csv to convert a malformed csv file (one that uses \x01 unicode as a separator) into a correct one. ...
0
votes
1answer
46 views

Why are my variables not reset to zero?

In the below loop, I try to reset the values of two variables (totalentries and totalusedbytes) to zero, but I can see from the results that it never happens. Thus each loop continues to add to the ...
0
votes
1answer
41 views

Shell— print only certain lines from output

I need to choose from output only lines where number is bigger than chosen number. For example x=27 and I need to find only lines where the number in first column is bigger than that x. In this ...
2
votes
1answer
23 views

Removing line numbers from `od`'s output

Is there any flag to od to make it not output line numbers in the result?
-2
votes
0answers
32 views

Combine lines of file to string [duplicate]

I am trying to have a file inputted by my script and put into a string to be put into another file. ./script.sh -u uuids.txt -s servers.txt Each file will have a list with each value being on it's ...
2
votes
1answer
58 views

bash: how to save state on prompt evaluation

I want to put duration of last running command in command prompt, f.ex: user@host$ sleep 360 6m user@host$ Also, I want duration to not show up if it is less than some minimum threshold (say 30 ...
-2
votes
3answers
33 views

Syntax error when trying to cut part of a variable

If I write a simple echo $i, I have no problem: it shows me the variable. But if I try do something with it $($i|cut -d"." -f1-3) then I get an error messages : -bash: /...file.backup: Permission ...
0
votes
3answers
54 views

How to make backticks accept variables as variables?

This is my code: #!/bin/bash machine_we_are_looking_for=$1 user_defined_new_machine_location=$2 condition_while_one=true condition_while_two=true echo "test 1" while $condition_while_one do ...
0
votes
0answers
11 views

Google Chart - Using Bash to dynamicaly add data - collected from a MQTT stream

I can collect data from the MQTT stream, I was curious to know 'how' I can push this data dynamically to the Google Charts with BASH/Shell script? This script will eventually be running daemon ie 'run ...
0
votes
1answer
72 views

Temporary file BASH

does this piece of code creates temporary file? Because I am not supposed to use them and I only found out yesterday that even sed -i creates it. So I can be sure. Thanks while read line; do if [[ ...
1
vote
0answers
36 views

Bash script to get the result from rsync transfer and zip it as a directory in the original directory

OK, I guess this is weird. I have a small stage.sh script very simply has a bunch of commands: if [ "$(whoami)" == 'David' ]; then rsync -a --delete-excluded --exclude-from=.stage_rsync_rules ...
2
votes
2answers
20 views

Can someone explain exactly what is happening with single quotes and double quotes with process IDs in the below example? [duplicate]

[root@localhost ~]# echo $$ 16991 [root@localhost ~]# bash -c "echo $$" 16991 [root@localhost ~]# bash -c "echo $$" 16991 [root@localhost ~]# bash -c 'echo $$' 21062 [root@localhost ~]# bash -c 'echo ...
2
votes
2answers
77 views

How to remove duplicate files using bash

I have a folder with duplicate (by md5sum (md5 on a Mac)) files, and I want to have a cron job scheduled to remove any found. However, I'm stuck on how to do this. What I have so far: md5 -r * | ...
1
vote
1answer
44 views

Why are files and directories colored in different ways? [duplicate]

On Ubuntu 14.04, in bash under gnome terminal, Why are files especially directories colored in different ways? The green colors hide the text to me (How about to you?). Is it done by terminal or ...
0
votes
0answers
24 views

Would this command delete only the lines containing specific words within a delimited area? [duplicate]

Please see my previous question here. No one seems to be following up on it, so I have tried to have a go myself: sed '1 { /^---/ { :a N; /\n---/! ba; /^Title: \|^Place: /d} }' filename Would this ...
20
votes
7answers
935 views

`command .*` acts on the parent directory

Someone of our team wanted to recursively change the user permissions on all hidden directories in a users home directory. To do so he executed the following command: cd /home/username chown -R ...
0
votes
0answers
60 views

Combine lines of file to string [on hold]

I am trying to have a file inputted by my script and put into a string to be put into another file. ./script.sh -u uuids.txt -s servers.txt Each file will have a list with each value being on it's ...
0
votes
0answers
47 views

Replace a string with another string in a text file [on hold]

I want to replace a string that is in the file file1 with another string. I tried sed -i -e "s/chaines1/chaine2/g" file1 but the problem is I can't pass the two strings on the command line ...
2
votes
3answers
52 views

What happens if I pass too few parameters to a shell function?

I would like to ask about passing parameters into functions. I tried this: function_name $var1 $var2 but usually (sometimes it printed error) it didn't make any difference whether I passed them or ...
2
votes
1answer
33 views

Can I re-login a disconnected session? [duplicate]

For some network reasons, my previous SSH sessions to server have disconnected. When I create a new session, I find the previous session still exist: [root@localhost ~]# who root pts/0 ...
3
votes
1answer
33 views

how to send output of curl request to 2 separate commands

I'm piping the output of a curl request to gawk so that I can pull some data. The gawk code is already working if I'm searching through the html file which curl request produces. However, I was ...
2
votes
3answers
55 views

One-liner for getting an IP address of an internal DNS name?

I have an internal DNS name for which I'd like to get the IP address. Is there a nice Bash one-liner I can issue to convert internalip1.mydomain.com into 10.10.10.10?
2
votes
1answer
91 views

grom() keyword in bash throws unexpected '(' token

I'm not entirely sure why I'm getting the error in my .bash_profile syntax error near unexpected token `(' when I use the keyword grom() for my function. I wanted to create a bash function that ...
4
votes
1answer
89 views

Can 'ssh <host> <command>' be configured to always load server-side startup files?

I would like run remote ssh commands and have them always load server-side startup files by default. I am looking for a solution that does not require: configuration by root adding extra boiler ...
1
vote
2answers
41 views

Remove paragraph from file

I have a file (file.php) like this: ... Match user foo ChrootDirectory /NAS/foo.info/ ForceCommand internal-sftp AllowTcpForwarding no GatewayPorts no ...
1
vote
1answer
53 views

Brace expansion not working in a script

for i in {1..40} do echo $i done I got {1..40} and I would like to have something like 1 2 3 and so on so I can use the variable i inside a command's parameter.
0
votes
1answer
37 views

User Input Bash Script

I am trying to make a Bash Script that has 4 choices and prompts the user to select an option. Each option corresponds to a Linux Command operation. Can someone give me a bash example on how could ...
0
votes
4answers
60 views

Copy same specific parts of a file to another file

How can I copy same specific parts of a file to another file? In the first file, I have: user01: Id name nationality user02: Id name nationality . . . I want to copy each piece of information to a ...
1
vote
2answers
32 views

Bash autocomplete: does not list files or directories

In my bash terminal, I would usually press tab twice to get the file and folder list. For instance cat 2XTAB would list all files and folders in the present directory and cd Proj2XTAB would list all ...
2
votes
1answer
36 views

How to verify the target of a symbolic link points toward a particular path

Within a bash script, I know I can check if a file is a symbolic link with the following syntax if [ -L $path ] Does any one know how I would test if that path was linked to a particular path? E.g. ...
0
votes
0answers
33 views

Compare specific word counts without variables or expr

I am tasked to write bash command to count number of specific words (given in file) in 2 files and write an error message if number of these words in first file is more than 3 times biggen than in the ...
0
votes
0answers
29 views

How to get and print a user's public IP address in a Shell Script? [duplicate]

I've just completed a lengthy installation script that deploys a Ruby on Rails application unto web servers. At the end of this script, I'd like it to print something along the lines of: "Installation ...
0
votes
0answers
16 views

MYSQL dump of tables that start with docs_ from one server to another

The headline says it :) I would need script that dumps all tables from 'ads' database on different server(s2) starting with 'docs_' copied to my server(s1). Any hints? The reason that I need script is ...
1
vote
1answer
31 views

Search for text inside java command output

I have a folder which have multiple Jar files. * dummy.jar * myjar-xx.jar * myjar-yy.jar Using find, I need to find first file starting with "myjar" Now, I want to grep the contents of ...
4
votes
1answer
46 views

Why does 'jobs' always return a line for finished processes when run in a subshell within a script?

Normally, when a job is launched in the background, jobs will report that it is finished the first time it is run after the job's completion, and nothing for subsequent executions: $ ping -c 4 ...
2
votes
0answers
28 views

Avoid that Ctrl-C disables input printing

On one of our servers, whenever I kill a process with Ctrl-C (e.g. to terminate a tail -f process), my input to bash is not printed anymore. I can blindly type reset, which solved the situation, but ...
1
vote
1answer
35 views

How does 'bash' or 'gnome-terminal' print user and path information? [on hold]

I am wondering if there is a different mechanism between printing user and path information(e.g. "guest:~/home/guest$") and command outputs. When I try to PIPE stdin and stdout of "bash", I can only ...
2
votes
0answers
29 views

Is there a nice way to set directory/project local environment variables?

I have been working on several projects and they require different environment variables (e.g., PATH for different versions of clang executables, PYTHONPATH for several external modules). Whenever I ...
1
vote
1answer
43 views

Printf formatting with variable format - what does this var reference?

I am experimenting with printf formatting in bash and I ran across this piece of code: #/bin/bash divider=============================== divider=$divider$divider header="\n %-15s %8s %10s %11s\n" ...
2
votes
2answers
80 views

How to print from a given range of ip addresses every class-c with the last octect replaced by an asterisk

example: I have a range from 10.0.100.0 to 10.0.224.0 and I want the output like this: 10.0.100.* 10.0.101.* 10.0.102.* and so on
5
votes
2answers
441 views

Why doesn't $@ work when passing strings?

For example, using this script: #!/bin/bash for a in $@ do echo $a done And running:./script "x y" z returns: x y z and not: x y z Why is that? And how would I pass string arguments with ...
1
vote
1answer
52 views

cat .bash_history | grep ./configure [closed]

Why does this not give any output: cat .bash_history | grep ./configure on an system/in an shell where ./configure has been run multiple times. And if I use the arrow key's to scroll the history in ...