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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0
votes
3answers
1k views

How do you create and execute a bash script which calls an executable from higher folder?

I'm attempting to write a very simple script which calls an executable from a higher level folder. If I were just typing the command into the console, I would type ../filenamehere {options} ...
3
votes
2answers
102 views

Add arguments to bash -c

Let say that I want to run a command through bash like this: /bin/bash -c "ls -l" According to bash man page, I could also run it like this: # don't process arguments after this one ...
5
votes
8answers
344 views

Remove last character from an echo variable

This script works great and I modified it to increment by 5. My problem is I do not need the last comma at the end and I'm not sure how to remove this. for ((i=1, j=0; i <= 12 ; i++, j=j+5)) do ...
7
votes
3answers
451 views

Run a diff between local and remote file

I'm connected on a host via ssh and I'd like to compare (let's say with diff) a certain config file against its counterpart on another host, also accessible via ssh, without having to manually ...
7
votes
2answers
307 views

Need help on this bash auto completion script

I'm trying to setup autocompletion for a command, which takes only one parameter, a folder name, In /secure/kernel_builds/, I have the three following subfolder: 3.5.6/ 3.6.2/ source/ Now I want ...
2
votes
4answers
70 views

Why am I getting inconsistent IP values from icanhazip.com or curlmyip.com?

I wrote a bash script and appended to my crontab to query my IP address every minute, and if it is not the same with the previous query it sends me an e-mail to inform me for the IP address change. ...
4
votes
0answers
59 views

KVM reports strange CPU usage peaks (bash infinite recursion)

On a KVM machine running Fedora 20 I ran ulimit -s unlimited (this removes limit on stack size) and an experimental torturing testing script. All this script does is just infinite recursion: ...
4
votes
5answers
303 views

Bash pattern to match all files but directories

In bash, how do I specify a pattern that matches everything but subdirectories in current directory. Given that the pattern */ matches all the subdirectories, I tried (with extglob turned on): $ echo ...
2
votes
1answer
38 views

How can I find where LANG, LANGUAGE and MAIL environmental variables are set?

I've had a few issues with environmental variables not set correctly in my Raspbmc Raspberry Pi. Specifically, I've had to manually specify the following in ~/.bashrc. export LANG='en_AU.UTF-8" ...
2
votes
2answers
109 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
6
votes
3answers
3k views

Is there a way to call a command with a set time limit and kill it when that time passes? [duplicate]

Possible Duplicate: Run a command for a specified time and then abort if time exceeds I was working on a continuos integration build script when a need for such a command arose. Basically ...
0
votes
1answer
31 views

Unix - Addressing filename with space for script [duplicate]

I have files Deep.flac and A1 - Rolling In The Deep.flac I wrote the script below, however it can only work with Deep.flac It cannot seem to work with filenames with spaces. I am newbie, learning ...
18
votes
4answers
7k views

How do I exit a script in a conditional statement?

I'm writing a bash script where I want to exit if the user is not root. The conditional works fine, but the script does not exit. [[ `id -u` == 0 ]] || (echo "Must be root to run script"; exit) ...
2
votes
1answer
41 views

Parameter substitution and error messages: suppressing line numbers etc

Here is my example file: !/bin/bash # argument-one # Is first argument missing? # First method [[ "$1" == "" ]] && echo "Usage: $(basename $0) filename"; exit 1 # Second method # ...
3
votes
2answers
27 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 ] ...
3
votes
3answers
115 views

Is the output mixed like this because of xargs and how can I fix it?

I'm learning a bit of Bash by using xargs to list whois records for a bunch of IP addresses. The command used is: echo "$1" | tr "\n" "\0" | xargs -0 -n 1 -t -P 3 -I % sh -c 'echo "\n 44rBegin whois ...
0
votes
2answers
99 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)
3
votes
1answer
58 views

find files without extension

Let say I have: foo.txt bar baz.ooo If I use ls -1 !(*.*) then I'll get only bar on the output. Great, now I wish to have same results with find - some find -regex that will do the job. NOTE: ...
3
votes
2answers
28 views

xargs how to put result {} into $(cmd {})? [closed]

for example: find /usr/lib -maxdepth 1 -type l -iname "*libblas*"|xargs -I{} echo "{} =>" $(realpath {}) I would like it to output: /usr/lib/libblas.so.3gf=>/usr/lib/libblas/libblas.so.3gf.0 ...
3
votes
2answers
232 views

Trouble w/ bash programmable completion of filenames matching patterns

I've got a simple command named th. I've got a bash-completion file for it that goes as follows: _th() { COMPREPLY=() local curr=${COMP_WORDS[COMP_CWORD]} COMPREPLY=( $(compgen -f -X ...
2
votes
2answers
22 views

Writing content from a file to another file on set time intervals using delimiters

I'm trying to write a script in bash that reads a file file1 and writes to another file file2 every 2 seconds, which is easy enough. However, I want to write to file2 on either a line by line basis ...
0
votes
0answers
32 views

Calculate Total disk i/o by a single process [duplicate]

I am looking for some tool that will dump total disk I/O by a single process after it ends. So far my finding is :- iotop= It shows i/o per process in real time but does not give total after process ...
3
votes
0answers
105 views

bash does not autocomplete my command when using sudo?

I'm using SaltStack. I would like to auto-complete the minion name when calling salt command. The following line has been added into ~/.bashrc: complete -o default -o nospace -W "$(sudo ls -1 ...
2
votes
1answer
30 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 ...
1
vote
1answer
38 views

Why does the same sed regex (after grep) fail when run in a bash script vs bash command line?

Here's the script. It is successful when I run it from the BASH prompt, but not in the script. Any ideas? When I say "fails," I mean the sed regex doesn't match anything, so there is no replaced ...
2
votes
3answers
145 views

in bash, read after a pipe is not setting values

Edit : original title was "read fails in bash" With ksh I'm using read as a convenient way to separate values: $ echo 1 2 3 4 5 | read a b dump $ echo $b $a 2 1 $ But it fails in bash : ...
0
votes
1answer
40 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 ...
0
votes
2answers
56 views

How to count number of instance of a word starting at another word

I need to grep the MySQL-error log starting at today's date formatted like: `date +"%y%m%d"` (140710) And look for all instances of the word partitioned. I've tried various things to no avail. ...
1
vote
0answers
40 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
2answers
836 views

Keep global variables values piping through functions

I wrote a little bash script using sed on some html pages to extract some urls. To avoid each time grabbing sed results in a variable then read it again I simply made 3 functions and piped together. ...
3
votes
1answer
30 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
1answer
114 views

how to edit and color bash's tab completion list

Following is what i would like to have. When the tab completion is ambiguous, and bash prints the list of possibilities. I would like it to colour the next character I should press inside every word ...
7
votes
5answers
173 views

Can a program next in a pipeline see the exit code of the previous program?

I would like to make a pipeline of Bash scripts like this prog1 | prog2 such that prog2 can see the exit code of prog1 and act differently based on that information. Is this possible?
0
votes
0answers
23 views

-bash: android: command not found

I'm on a Mac running Mavericks trying to learn how to develop Android apps (in the process I'm learning bash too). To run on the emulator they suggest the command android avd. I always get the error ...
3
votes
6answers
131 views

ls content of a directory ignoring symlinks

I have a directory in which I would like to list all the content (files and sub directories) without showing the symbolic links. I am using GNU utilities on Linux. The ls version is 8.13. Example: ...
1
vote
2answers
47 views

Merge csv files with conditions

I have 2 CSV files for each date (csv_2014_4_15 and csv_2014_4_16) , with basic structure and couple of unique columns as below. id,name,created_at,updated_at,other columns 12, joe, 2013-1-1 18:30, ...
1
vote
1answer
22 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
2answers
130 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 ...
2
votes
2answers
175 views

How to parse multiple string patterns in linux shell script

I am new to linux shell and I had a hard time thinking of the solution to this. Can somebody help how to parse multiple strings (data) in a file? For below file, I want to parse all the values next to ...
10
votes
3answers
592 views

Is there any major difference when comparing a variable as a string or as an int

Out of curiosity, when doing a bash variable comparison (its value being an integer) it's possible to test it against some predefined value either declared as an int or as a string. Sample script: ...
3
votes
2answers
100 views

Bash autocomplete variables for other commands than cd

I have env variable $SCRIPT. Normaly I can use autocomplete vim $SC<tab> and completion works as expected. On some systems it does not work. I have bash completion loaded, but completion in ...
6
votes
2answers
154 views

Batch rename image files by age plus add date and variable to filename

The question is completely rewritten due to things learned from the first two answers and comments that I was unaware of when first asking. After a photo shoot I come home with files that look like ...
4
votes
3answers
147 views

Adding comments using 'set -x'

Sometimes it is really handy to just add set -x to the top of your script to show all commands before they are executed. There is only one drawback creating scripts with a decent output: I don't ...
2
votes
1answer
68 views

Integer part from float operations without | bc

I read a billion of discussion about this but still have confused thoughts. I just need to use bash to calculate some parameters, and for this operation I need to get the integer part of a float ...
1
vote
1answer
54 views

Searching history forward after backward?

In bash, when I hit Ctrlr, I can search the command history backward. If I would like to search forward again, what shall I do? I hit Ctrls, but it doesn't work. My bash is GNU bash, version ...
5
votes
4answers
91 views

Have xargs use alias instead of binary

Bash 4.2 on CentOS 6.5: In my ~/.bash_profile I have a bunch of aliases, including: alias grep='grep -n --color=always' so that I can get color highlighting and print line numbers automatically ...
4
votes
4answers
5k views

How to totally fork a shell command that is using redirection

I've written quite a few shell scripts over the years (but I'm certainly not a sysadmin) and there's something that always caused me troubles: how can I fork a shell command immune to hangups in the ...
0
votes
2answers
487 views

Comparison of shells? [closed]

Do shells have any actual advantages or disadvantages? They can all run any binary, they all support pipes and > (output to file). Why would one choose bash over sh, or sh over ksh, etc? Why does ...
1
vote
2answers
60 views

Configure bash and/or vim to execute source ~/.bashrc everytime I finish editing it

I would like to execute source ~/.bashrc every time I finish editing a file with vim (i.e. after :wq vim command). How should I configure vim or bash to work that way?
1
vote
3answers
87 views

How to escape special characters in a string?

Assuming $file holding a value of a file name, say Dr' A.tif. In bash programming, how could I escape single quote and any other special character of the $file without removing the special character? ...