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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3
votes
1answer
53 views

Suppressing “sudo: sorry, a password is required to run sudo” [closed]

I am trying to test if a user has the required sudo rights to run a command as another user without providing a password. What I have is this sudo -u other-user -n true if [ $? -ne 0 ]; then ...
3
votes
1answer
115 views

Add autocompletion for custom script

I am currently working on a shell script I called makeyourself.sh (linked to /usr/bin/mys) which automatically installs a debian package from source (via apt-get source -b $1). So I decided to add an ...
1
vote
2answers
56 views

How to combine arithmetic expansion and brace expansion? [duplicate]

Can peoples combine arithmetic expansion and brace expansion? $ for i in {$((1 + 1))..5}; do echo $i; done; {2..5} $ echo "bash laughs at me"
0
votes
1answer
38 views

Bash STDERR still appearing after redirection [closed]

I am trying to parse the output of yum check-update in Bash 4 (Red Hat) and want to skip the first line that states: 'This system is not registered to Red Hat Subscription Management. You can use ...
3
votes
1answer
31 views

Bash ignoring my PATH and it's cache

I have installed pip in my ~/.local/bin/ directory. Here are the outputs of which, type and $PATH $ type pip pip is hashed (/home/bcc/pedros/.local/bin/pip) $ which pip /usr/bin/pip $ echo $PATH ...
2
votes
1answer
27 views

How to get clicked-on filename as argument of shell script triggered by this mouse-click

If, in Ubuntu's Nautilus, I click a midi-file, a window opens to specify an application for processing the file. Another option is a "user generated command" (UGC). (Let me choose Ubuntu, Nautilus, ...
3
votes
2answers
107 views

Bash -c with positional parameters

Usually, $0 in a script is set to the name of the script, or to whatever it was invoked as (including the path). However, if I use bash with the -c option, $0 is set to the first of the arguments ...
4
votes
1answer
115 views

`seq` and bash brace expansion failing

IINM my system is failing when bashing for i in {0..10000000}; # Seven zeroes. do false; done # `bash` exited and its `tmux` pane/window was closed. or for i in $(seq 0 10000000); # ...
2
votes
2answers
48 views

How to make bash script ask you if you want to execute the next segment(part)?

Soon as I execute the bash script. Given that I have set -x I will visually observe what is happening. But at certain parts, I want it to stop and ask me if I still want to continue executing the ...
18
votes
5answers
1k views

Is there a way to tell sudo to set my username as owner for the files created instead of root?

If I do a sudo cp /etc/foo.txt ~/foo.txt, the new file is created with root as the owner. Right now, I see no way around this other than using the last two commands (ls to clarify use-case): ...
0
votes
2answers
23 views

is there a way to escape a process in bash with out quitting it? [duplicate]

For example, I type sudo apt-get update and then a long list of stuff will come up for minutes.. if I want to escape from seeing this tiresome updating and take control of bash command line ...
5
votes
4answers
765 views

For each subfolder, sort files by name and rename them to sequential padded numbers (regardless of extension)

I have the following directory structure: . ├── event-a │   ├── album-a │   │   ├── a.jpg │   │   └── x.png │   └── album-b │   ├── a.jpg │   ├── x.png │   └── y.gif └── event-b ├── ...
2
votes
0answers
27 views

Bash tab completion fails inside of command substitution

I've been using kill $(pidof ) to terminate programs for a while, and since last night, every time I try to use tab completion inside the $() it throws an error, bash: unexpected EOF while looking ...
2
votes
2answers
88 views

find file, copy but with different name

I have files with random numbers in /home/user/files folder (every 4 days I have new ones). for example: john20 john25 john40 tom12 tom32 simon2 simon8 simon53 I want to take only last modified ...
3
votes
1answer
142 views

Set Ubuntu System Proxy Settings without Restart from commandline

I am using Ubuntu 14.04 . I want to change the http proxy settings from the command line. This should be equivalent to changing in the GUI(All Settings->Network->Network Proxy) and clicking the button ...
1
vote
2answers
36 views

Restarting a service from a script

I have a init script - /etc/init.d/myservice, which starts some processes, including a CLI process. And from this CLI process, I am adding a command which can be used to restart the service (restart ...
2
votes
1answer
110 views

Sort the 'last' output by month

I know that the command last | tac is enough, but I want to do it using the sort command. I cannot sort it by column, it always sorts the first one only. Using bash on Arch Linux.
0
votes
0answers
40 views

Is there any suggestion to my bash script that (un)mounts an ISO file in order to make it better and safer?

I am new to bash script, and I wrote a script to mount / umount an iso file by detecting whether the /media/iso-file-name exists. Is there any suggestion for the script as below in order to make it ...
1
vote
1answer
90 views

How does bash execute an ELF file?

When I'm on my Linux Box I use bash as a shell. Now I wondered how bash handles the execution of an ELF file, that is when I type ./program and program is an ELF file. I grepped the bash-4.3.tar.gz, ...
2
votes
3answers
155 views

Saving individual output lines into variables

I'm using find -mtime -2 to find files modified in the past 24 hours or less. The output looks like this. /home/user/logs/file-2014-08-22.log /home/user/logs/file-2014-08-23.log I need to save the ...
1
vote
2answers
36 views

Find out which process is in foreground on bash

I have a bash session open for which I have the PID, although I am not in control of the terminal (e.g. could be another user). This bash session has spawned some child processes. Is there any way to ...
5
votes
4answers
2k views

How to make bash put prompt on a new line after cat command?

What I get: host:~ user$ cat example.txt some texthost:~ stas$ What I want to get: host:~ user$ cat example.txt some text host:~ stas$ Is there a way I can make cat behave like this? I'm using ...
2
votes
3answers
59 views

at job seems to be running using /bin/sh though I have a #!/bin/bash

I am trying to run a job using at, and I have a bash script (I do have #!/bin/bash as the first line), but the job fails because of use of [[ and ]] in the script, I see the following in the mail that ...
6
votes
1answer
83 views

Getting wrong $LINENO for a trapped function

I am writing a Bash script for myself to learn scripting. At some point, I need to add trap in order to clean unwanted directories and files if script is killed. However, for some reason I do not ...
1
vote
2answers
57 views

How do I validate a settings(ini) file for the values expected using bash?

After I check if the ini file exists where it is expected to be, which I've learned how to do, I would like to check the file for proper formatting. I'd like to validate any number of "site" entries ...
4
votes
2answers
4k views

Bash : compare two strings with space

I am trying to write a bash script which run a command and compare the result with another string. #!/bin/bash -x STATUS=`/root/setup_ha show --password-file=/root/password | grep ">HA State" | ...
1
vote
3answers
7k views

Yum update problems on CentOS 6.5 minimal as VMware guest

INFO: I am using Windows 7 Pro (64bit) with VMware Workstation version 10.0.1 . I am using CentOS(64bit) 6.5 minimal, for the first time. I am running this from my workplace network, which may use a ...
1
vote
1answer
46 views

Copy newest file in directory over SSH

How might one copy the newest text file from a particular directory on a remote server to his local machine? On the server itself I can do the following: $ cat `cd /home/user/dir ; readlink -f $(ls ...
2
votes
1answer
242 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 ...
2
votes
3answers
109 views

Script to ssh and run a command doesn't work

Below is the script. I wanted to login several servers and check for the kernel version. #!/bin/bash #input server names line by line in server.txt cat server.txt | while read line do sshpass -p ...
1
vote
1answer
98 views

^C characters at start of line break bash command editing

I have a problem with command editing in bash. If all of the following are true... My (single-line) prompt is particularly long. The terminal window is relatively narrow. I pressed Ctrl+C to exit ...
118
votes
10answers
32k views

Preserve bash history in multiple terminal windows

I consistently have more than one terminal open. Anywhere from two to ten, doing various bits and bobs. Now let's say I restart and open up another set of terminals. Some remember certain things, some ...
9
votes
1answer
3k views

Terminal autocomplete: cycle through suggestions

I had this on my Ubuntu setup and since I switched to Fedora I want to set it and I forgot how... The idea is simple : I don't want the terminal to show me suggestions when I double tab, instead I ...
3
votes
5answers
166 views

efficient cross-os file size shell function

I'm looking for a simpler way to have a cross-os-unix file size check. I could use wc -c but I'm concerned the performance may suck on large files (I'm assuming it just counts chars and doesn't do a ...
2
votes
1answer
24 views

ionCube shell script gives error

I have this shell script to install ionCube loader: if [[ $(id -u) -ne 0 ]] ; then echo "Please run as root" ; exit 1 ; fi echo "Welcome to this script to install the ionCube loader on CentOS!" cd ...
12
votes
3answers
854 views

How to eliminate annoyances when starting a GUI from a terminal?

I prefer to launch GUI applications from a terminal window rather than by using a graphical desktop. A frequent annoyance is that often the developers haven't anticipated this type of use, so the app ...
2
votes
3answers
67 views

Checking if an input number is an integer

I'm trying to check if an input is an integer and I've gone over it a hundred times but don't see the error in this. Alas it does not work, it triggers the if statement for all inputs ...
8
votes
1answer
3k views

How to specify a custom autocomplete for specific commands? [duplicate]

Is there a way to have bash know exactly what to display when you double tab? For example I have a python script scpy which requires a couple arguments. For example like apt-get, if you double tab ...
5
votes
1answer
27 views

Upstart and bash function names containing “-”

I inherited some bash scripts where the author used "-" in the function names instead of the more normal "_" e.g.: function a-b { ... } Ugly but legal in bash. Problem is I sourced this inside an ...
0
votes
2answers
38 views

how to pass a value to a variable that in a other variable

I am new to scripting. I am getting a "bad substitution" error while running this code. I want to print the values in h_1, h_2, h_3with a for loop. #/!/bin/bash h_1=12 h_2=13 h_3=14 for ((i=1; ...
16
votes
7answers
11k views

Using xargs with input from a file

Say I have a file with the following bob john sue Now these directly corrospond to (in this case) URL pattern such as http://example.com/persons/bob.tar, john.tar, sue.tar. I would like to take ...
1
vote
3answers
2k views

How can I run a “grep | grep” command as a string in a bash function?

I'm trying to build a command that pipes the results of one grep command to another grep command in a bash function. Ultimately, I want the command executed to look like this: grep -I -r FooBar ...
1
vote
3answers
118 views

Calling a function which calls another function with a for loop

I am calling a function with a for loop and saving the returned value to a variable. When I run the code, I get a command not found error. What is wrong? #!/bin/bash check_1() { x_$1=$(check_2 ...
1
vote
2answers
1k views

using bash script to output new script: need mixture of variables to be replaced and not replaced

I'm having a problem with bash variable substitution. Here's a silly example of what I am trying to do. I need to output a new script from a bash script. A line (see echo in my example) has a mixture ...
0
votes
2answers
469 views

“Expect” automation tool output to shell variable

#!/bin/bash # more commands here expect << EOD spawn telnet localhost 9151 expect -exact "Trying 127.0.0.1...\r Connected to localhost.\r Escape character is '^]'.\r" send -- "AUTHENTICATE ...
2
votes
2answers
133 views

How to check whether a particular port is open on a machine from a shell script and perform action based on that?

I am running my below shell script on a machine on which c++ application server is running on port 8080 and in the shell script I am executing an URL and stores the response coming from that URL in ...
4
votes
4answers
93 views

Bash history in script: `!#:*`

I have been reading through the study guides for the LPIC-1. echo "This is a sentence. " !#:* !#:1->text3 I'm having trouble understanding how the above line of code repeats the echo command ...
1
vote
1answer
84 views

Command-line parameters in bash script not recognised

I use Debian (Raspbian) Wheezy. If this command line works fine: smsd -c sms/out -i 60 -0 -f sms/smsd.log and this alias also works fine: bsmsd='smsd -c sms/out -i 60 -0 -f sms/smsd.log' then ...
0
votes
2answers
76 views

change the extension of all files based on user input

I was taking an online assessment and I got the below question. Create a script located at /usr/local/bin/set-file-extensions that will change the extension of all files in the directory ...
1
vote
1answer
891 views

How can I change my bash prompt to show my working directory?

I can print my current working dir like this myPrompt$ pwd /Users/me/myDir I want my shell to look like this /Users/me/myDir$ pwd /Users/me/myDir Is that possible? How can I do it?