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
2k views

Comparing Files based on 5 fields using Awk and Bash

I want to compare File1 and File2 (Separated by spaces) using five fields (Column 1,2,4,5,6). *Logic:*If column 1 and 2 of File1 and File2 match exactly and if the File2 has the same characters as ...
3
votes
2answers
767 views

screen /bin/bash execute script and then go to interactive shell

I am using .byobu/windows to start up some screen sessions, and I'm trying to start a script that will exit to an interactive shell once it has completed. Is this possible? I've tried: screen -t ...
2
votes
3answers
13k views

Testing remote TCP port using telnet by running a one-line command

I have numerous linux boxes with a very limited set of commands and disk space. But it has the telnet command on it. I remotely connect to each of these probes (programmatically) and issue one line ...
1
vote
1answer
175 views

Searching for all the array elements in another array?

This is how I would search for an element in an array. count=${#ARRAY[@]} lsearch() { status=-1 for((i=0;i<count;i++)) do Temp=$1 if [[ $Temp -eq ${ARRAY[i]} ]] then ...
2
votes
3answers
7k views

Executing a program with various parameters (loop)

I have a program, prog, which takes an integer argument when I call it from the terminal, eg: ./prog 10 I would like to execute prog with a range of values, e.g. 10, 20, 30, .... Is there a neat ...
1
vote
2answers
251 views

shell saves ip address that you ping? [duplicate]

I was once shown a shortcut that I can't recall/ find. After pinging an ip, then attempting to ssh into it - the ip was saved into to a variable automagically. Something like: ping 10.1.23.4 ...
1
vote
1answer
338 views

Why is variable interpolation not working for variable assignment (for bash)? [closed]

I have this script: ROOT=/tmp LOG=$ROOT/blah.log echo $LOG The output is: /blah.log obviously the ROOT variable is not being interpolated which is very unexpected. If I echo $ROOT, it correctly ...
1
vote
2answers
392 views

How to extend a command in bash so that it expands based on options?

I've started working with a git repository that includes a large amount of content that should be assumed readonly. So, every time I throw a new branch: git checkout -b newBranch it should be ...
2
votes
2answers
15k views

How to sort results from ls command by modification date (directories first)?

I can fire ls -lrt to get files and folders sorted by modification date, but this does not separate directories from files. I want ls to show me first directories by modification date and then ...
28
votes
8answers
87k views

How can I display the contents of a text file on the command line?

I would like to display the contents of a text file on the command line. The file only contains 5-6 characters. Is there an easy way to do this?
3
votes
2answers
6k views

Use inotifywait to move file when it loads in dropbox folder

I'm trying to find a way to immediately move a file to another folder as soon as it appears in my dropbox on CentOS. I have scoured the internet for some clues but I can't get any further than the ...
25
votes
4answers
5k views

How do you use the command coproc in Bash?

Can someone provide a couple of examples on how to use coproc?
19
votes
4answers
3k views

Make bash use external `time` command rather than shell built-in

How can I make bash use time binary (/usr/bin/time) by default instead of the shell keyword? which time returns /usr/bin/time type time returns time is a shell keyword Running time is obviously ...
3
votes
2answers
158 views

bash equivalent of zsh's $@[2,$#]

(NB: the motivation for this question is only to improve my bash programming know-how.) I want to know the bash equivalent of zsh expressions such as $@[2,$#], which directly address a range of a ...
2
votes
4answers
1k views

Why is bash interpreting characters that I have character escaped? [duplicate]

Why is it that when I run curl against a REST API, the special characters (!) in my key are interpreted by the shell? curl https://foo.my.salesforce.com/services/data/v28.0/ -H "Authorization: ...
3
votes
1answer
2k views

viewing dll and exe file properties/attributes vi command line

I have a need to see some additional file properties for exe and dll files. If I open windows explorer and add the additional columns to my view, I can see things like Company, Copyright, Product ...
4
votes
2answers
159 views

What configuration can insert lines between commands?

I've noticed on some Linux servers, that bash has a very elegant feature that adds visual breaks. What program is it that appends the -------- <time> after each command?
3
votes
2answers
231 views

Preventing accidental directory deletion. Making an alias that contains options?

I use an alias to prevent me from accidentally deleting files, and I would like to do something similar for directories. For files, I have the following added to my .bashrc: alias rm="rm -i" I ...
14
votes
5answers
584 views

Use same arguments with different command [duplicate]

Here's something I find myself doing often: less super/long/file/name Followed by: vim super/long/file/name Is there an easy way to pass the args of the previous command over to the next? SO I'd ...
4
votes
1answer
224 views

Pipeline and redirection understanding

Please explain this script (from ABSG. Ch. 20): exec 3>&1 # Save current "value" of stdout. ls -l 2>&1 >&3 3>&- | grep bad 3>&- # ...
37
votes
4answers
13k views

What is the purpose of the hash command?

If you run hash it shows the path of all commands run since the hash was last reset (hash -r) [root@c04c ~]# hash hash: hash table empty [root@c04c ~]# whoami root [root@c04c ~]# hash hits ...
7
votes
4answers
3k views

Bash script to rename files from a text file source

I'm fairly new to bash; I can just about perform simple administrative tasks with simple commands 1 at a time. However, I've been tasked with renaming some files in a directory using a text file as ...
1
vote
1answer
92 views

Mass file+folder+directory move

So we have a bunch of src files that are old and out-dated and need to be moved to our new NAS storage. (I don't know why we are keeping them). Is it possible to copy all the files and folders with ...
1
vote
3answers
283 views

Taking Backup of files of particular limit in unix

Here is the scenario, I have 1000 files in a folder each ~3 MB. I want to zip all files into 50MB each zip and remove the original files. NOTE: 50MB may contain 20 files or 10 files but that zip ...
2
votes
2answers
3k views

Get list of all files by mask in terminal

I want to find all *.h,*.cpp files in folders with defined mask, like */trunk/src*. So, I can find separately *.h and *.cpp files: find . -path "*/trunk/src/*.h" find . -path "*/trunk/src/*.cpp" ...
0
votes
1answer
2k views

if condition, loop in grep [closed]

Could someone please provide help for me. I tried to start writing a shell script but am getting hung up with this issue. I need to grep commands "adb shell ps" and find in it 3 processes with names: ...
2
votes
0answers
3k views

ssh-agent not getting set up (SSH_AUTH_SOCK, SSH_AGENT_PID env vars not set)

I set up a new user account for a friend on Kubuntu 12.04. When he uses ssh he gets this error: Could not open a connection to your authentication agent We're running ssh in some bash scripts. ...
3
votes
1answer
329 views

Variable declaration in parallel sh -c …

I've been trying to process the output of find with parallel, which in turn invoked a shell (some textual substitutions were needed). I observed some strange behaviour, which I cannot really explain ...
1
vote
1answer
264 views

Launch 2 celery processes via cron

I'm trying to chain some commands to periodically check/launch two processes via cron (I'm on a shared host, can't change things around). After a lot of googling around, all the things I've done don't ...
4
votes
5answers
4k views

grep for multiple strings in files, and then list the files in the order of size

I am in a folder with lots of .txt file, I would like to find all the files which contain both stringA and stringB (not necessarily on the same line), then list these files in the order of the size ...
3
votes
2answers
101 views

How to switch to editing command in text editor [duplicate]

When typing a complicated command that started on the command line in Bash, how do I switch to editing it with ViM?
3
votes
2answers
564 views

Why can't pgrep find scripts started via env?

For example: $ cat foo.sh #!/usr/bin/env bash while true; do sleep 1 ; done $ ./foo.sh & $ pgrep foo.sh $ Contrast with: $ cat bar.sh #!/bin/bash while true; do sleep 1 ; done $ ./bar.sh & ...
1
vote
1answer
532 views

Non-ASCII characters handled incorrectly on command line

I have a problem with non-ASCII characters in the Terminal on Mac. If I write: echo ÆØÅ Then press Enter, Arrow Up, Arrow Left, so the cursor is between the Ø and the Å, then write X, then the Å is ...
1
vote
1answer
682 views

Cron automated bash script to run run 1 bash script then another, plus integrity check

So I have a custom in-house app developed by a 3rd party. When the app is running, I can verify it is running with the "screen -ls" command. As long as screens are running for rails and freeswitch ...
5
votes
2answers
652 views

Why do I need the double dash before argument passed to sh by xargs -I for it to work properly?

Sorry for the mouthful title. Here is the command in question find . -name "*.txt" | xargs -Ifile sh -c 'echo $(basename $1) ' -- file So without the double dash the file is not passed to sh and ...
2
votes
2answers
14k views

Checking and changing file permission with script

I'm new to bash and I can't get a script working. This is the code that I have: #!/bin/bash file=~/scripts/text.txt if [ -e $file ] then echo "The file exists" elif [ ! -e $file ] then echo "The ...
1
vote
2answers
13k views

How do I process ifconfig output to determine my link speed?

Here's script I wrote out of boredom, for download speed test: #!/bin/bash get_ispeed() { echo $(ifconfig eth0 | grep bytes | grep RX | cut -d ':' -f 2 | cut -d ' ' -f 1); } for((;;)); do ...
4
votes
2answers
67 views

Is it possible to notify/warn that current path isn't a valid symlink anymore?

Let's say we have ./a and ./b directories. Then we create a symlink using ln -s a x and entering it cd x The pwd would be x Then in another terminal we change the x so that it pointed to b. But the ...
1
vote
2answers
822 views

how to escape unusual/uniq characters from expect scripts?

in expect script I can set any command or character to run it on remote machine but the sad thing is that expect cant send the same character as they defined in the expect script for example I want ...
3
votes
2answers
169 views

How to make .bashrc call dependant on tmux program being installed?

I have a section in my .bashrc that fires up the tmux program (terminal multiplexor). However if the tmux program isn't installed (say I'm setting up a new computer) then having this in my .bashrc ...
2
votes
0answers
105 views

Linux child processes not being culled [closed]

This is causing significant problems for script portability between BSD and Linux. I am on a CentOS 6.4 where this happens. I have a nice compact test case: bash -c "inotifywait -mcr . | sed ...
9
votes
1answer
5k views

Piping search term (not filename) to grep

I want to pick out certain lines containing a given number from a file. The file I want to search is called os_clusters/piRNA_clusters.bed. awk '{if (a[$0]++ == 0) {split($0,b,"."); ...
6
votes
1answer
3k views

how to enable command history of shell

I am using ubuntu 13.04, in this the command history of the shell is getting erased on close. Can someone tell me how to prevent this from happening?
3
votes
1answer
166 views

Where is the bash feature to open a command in $EDITOR documented?

I have recently discovered that if we press Ctrl+X Ctrl+E, bash opens the current command in an editor (set in $VISUAL or $EDITOR) and executes it when the editor is closed. But it doesen't seem to be ...
2
votes
4answers
2k views

Bash source — select the right function when two sourced files have the same function name?

My bash script sources a script file (call it file2.sh) according to an argument. (It is either sourced or not.) The script file2.sh contains a function "foo" (call it a modified or improved version ...
22
votes
2answers
5k views

How can I `alias sudo !!`?

I'm trying to set an alias for sudo !! in Bash. I tried alias sbb='sudo !!', but it interprets that as a literal !! and prints sudo: !!: command not found If I use double quotes, it substitutes ...
-1
votes
2answers
90 views

What's wrong with this tar command? [closed]

find /informatica/dev/SrcFiles* -mtime +7 -and -size +1M -exec tar -rvf files.8.2.2013.tar {} \; This command is running/working correctly and I'm not sure whats wrong. I want to find the files that ...
1
vote
0answers
392 views

gnome-terminal cmd leaving processes open after closing parent window

The following simple command should demonstrate my issue: gnome-terminal --tab -t "Tab 1" -e "/bin/bash" --tab -t "Tab 2" -e "/bin/bash" This should open a new window with two tabs and an active ...
5
votes
3answers
412 views

Can you pipe to a .bash_profile function?

I received a great function for highlighting files in Apple's finder using the command-line. It's basically a wrapper for osascript. I got it from Mac OS X: How to change the color label of files ...
3
votes
1answer
286 views

How to create a file with the name specified in ASCII encoding?

I want to create a file that is called ascii 007, which is the bell symbol, which is not printable. I tried nano $'\007', but that just created a file called ?; cat ? print the test content, that I ...