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
1answer
3 views

Getting the starting position in the history that will be appended to the history file (not read from the file or previously written)

I'm trying to write functions to remove some history lines using history -d before it is written to the file, while leaving them usable in the shell itself. But apparently this command will not ...
0
votes
1answer
25 views

Strange output when echoing variable from a different user

$ sudo su - user1 -c 'echo $DOMAIN_HOME' /app/user1/DOMAINHOME This looks fine, right? However, let's dig a little deeper: $ sudo su - user1 -c 'echo $DOMAIN_HOME' | tee test.out $less test.out ...
1
vote
2answers
32 views

Spawn multiple processes with a single command

Is there a way to create say 10 instances of a process (for example yes) with a single command? $instantiate 10 yes
-4
votes
0answers
46 views

What am i doing wrong with my script? [on hold]

#!/bin/bash echo echo These are the Users Processes top -b -n 3 | sed -n '6,12p' pid= top -b -n 3 | sed -n '7,12p' | cut -f1 for pid in 'ps -ef | grep $pid | awk '{print $2 }'' ; do kill $pid ; ...
0
votes
2answers
32 views

Getting error with sleep and argument in sh script [on hold]

I'm doing something like this #!/bin/bash END=3 time_w = 1 for ((i=1;i<=END;i++)); do # do something sleep time_w done but I'm getting sleep: invalid time interval ‘time_w’
0
votes
2answers
27 views

How can I break out of a while loop, from within a nested case statement? [on hold]

In the script below - which prompts the user to confirm that they want to proceed with running a potentially bad script - when the user enters Y at the prompt - it will break out of the case block, ...
0
votes
2answers
36 views

Using braces expansion to specify a set of paths: how to specify general branching principles? [on hold]

So, recently I've become obsessed with making an "elegant" CDPATH that suits my needs. While previously I had no idea you could use anything other than literal strings to define the variable, I ...
1
vote
3answers
41 views

Difference between sh -x and ./ for script execution

So I have a simple shell script. What is the difference between the two commands in execution? Is there a preferred way? $sh -x foobar.sh OR $ ./foobar.sh I found the script executed slower when ...
0
votes
1answer
23 views

How to ignore spaces in file path for bash select statement [duplicate]

I have the following Bash Script: #!/bin/bash cd ~/Library/Developer/CoreSimulator/Devices/; files=$(find . -name iaGambro_gambro.sql) select file in $files; do if [ -n "$files" ]; then ...
1
vote
1answer
24 views

finding a maximum and minimum file size along with their path in a directory

I want to find out the maximum, minimum and average file size along with their path. My code is: #!/bin/bash DIR="$1" echo "maximum file size:" du $DIR -h echo "average file size:" du $DIR -sbh ...
0
votes
1answer
25 views

how to run script with a clean login shell

I am connected to remote machine Linux RH6 directly via ssh (key imported on server), when I execute a shell script with arguments for restarting the java service, I have a strange issue with ulimit: ...
0
votes
2answers
38 views

No of files and directories in a particular directory in shell script

I am working on Linux and it's new to me. I created a shell script countfiledirs. I want to know the number of files and directories in a particular directory. My code is: #!/bin/bash echo "total ...
5
votes
2answers
152 views

Bash displays international characters as escape sequences

When I press certain keys (e.g. German umlauts) in the bash command line, I get escape sequences. For example, ß gives me \303. These escape sequences are treated as single characters, so one ...
4
votes
0answers
18 views

Search history from multiple bash session only when Ctrl + R is used, not when arrow keys are used

I usually have multiple bash sessions open. I want the history from multiple session to appear when doing a search (with Ctrl + R). When arrow keys are used only the current bash session's history ...
0
votes
1answer
18 views

How can I match and substitute this multiline pattern in a bash script?

I have a file jail.local and it has sections like this [apache] enabled = true logpath = /var/log/apache/error.log [ssh] enabled = false port = ssh I want to match on the string [ssh] and ...
2
votes
2answers
69 views

How is IFS really rendered?

I've read bash manpage and other docs, but I find the explanation a bit confusing. I have the following simple script: #!/bin/bash IFS="" echo $2 var=A B C echo $var if I execute it, eg: ...
-1
votes
2answers
23 views

How to use pass filename without extension to gedit external tool for make?

I am wanting to build and run a program called dbgen using the external tools. I know that this variable holds the filename, ‍‍‍‍‍‍‍‍‍dbgen.c‍‍ : $GEDIT_CURRENT_DOCUMENT_NAME How do I remove the .c ...
0
votes
1answer
37 views

List all file extensions in an arborescence and count number of occurences of each [duplicate]

I am looking for a simple shell function (bash prefered) to list all file extensions in an arborescence and count the number of occurences of each. For example, list_extensions . would return ...
0
votes
1answer
36 views

How can I populate an array in Bash Shell script loop

cmdline> ls -la /.myScript.sh set index=0 set usrlist[index]="null" while read line do #Total lines read z=`echo $line| wc -l` lines=`expr ...
10
votes
3answers
41 views

Why is my Bash script returning a syntax error?

I am writing a script which loops into recent files in a folder and executes a command... #!/bin/bash cd /home/Downloads recent_files = ($(ls -t | head -20)) for file in "${recent_files[@]}" do ...
-6
votes
0answers
30 views

Why changing variable position fixes the error [on hold]

I spent half hour trying to figure out why totusr=`expr $index + $totusr` was giving me syntax error then I did this totusr=`expr $totusr + $index` GUESS what its working.but why ?
-1
votes
1answer
53 views

what is shell script? [on hold]

Is that some thing like a programming language? Which does provide this option(facility) by a program running on linux or basic program that comes with linux kernel?
0
votes
1answer
44 views

How can I use sed to print out unique users [on hold]

I wish to print out the unique users in the system using only sed, using: ls -la | sed '/^$USER$/p' .... It gives me all files, matching to the current user, and prints out the lines they are in. ...
0
votes
1answer
21 views

Filtering Log Output on Separate Lines

I did a recursive grep in a directory to find all files that would match as follows grep -ER "match_string1|match_string2" /path/to/dir/ What I get as output is: ...
2
votes
1answer
95 views

bash time with nohup

I want to know how much time it takes to run something in nohup. I know this works: $ time sleep 2 real 0m2.001s user 0m0.000s sys 0m0.001s But why it doesn't work with nohup? $ nohup ...
0
votes
1answer
34 views

doubts in file system hierarchy? [duplicate]

explain the difference between /bin and /usr/bin used in Linux?
0
votes
0answers
26 views

include Forking - Multi threading in bash script to run it in upstart?

I have lack of understanding. Do i need to include forking in my bash script: http://stackoverflow.com/a/26756839/4749164, so i can use expect daemon/fork - option in upstart? i would like to run my ...
4
votes
2answers
37 views

How to kill a bunch of jobs based on ps output?

Here is output from ps $ps aux | grep blob ubuntu 4286 0.0 0.1 34748 9592 ? S Jan14 0:00 /usr/bin/python /usr/local/bin/pynt start_blob_reader ubuntu 4287 0.0 0.1 34748 ...
0
votes
0answers
12 views

Using brew: curl version error, “Incompatible library version” for libcurl.4.dylib

I used to have a working version of homebrew but then something broke today related to curl and libcurl.4.dylib— possibly a version or file location issue. I'm on Mac OS X 10.9.5 (Mavericks). For ...
-1
votes
0answers
28 views

Custom Command not found after sourcing .bashrc [on hold]

I wanted to add a function that could create custom alias so I added the following to .bashrc function addalias { echo "alias $1='$2'" >> ~/.bashrc } I then ran source .bashrc I tested ...
0
votes
1answer
42 views

What's the best way to make a bash function in a script as a parameter when running via command line?

I'm fairly new to bash scripting, and wondered what's the simplest way to make bash script functions in a script as the parameter when run via command line? Example usage: ./myscript function1 ...
0
votes
1answer
38 views

Log output from more than one script

I have a problem concerning the logging of a process: I have 3 scripts, a.py, b.py and c.sh a.py calls b.py and b.py calls c.sh The goal is to continuously log std out/err (write to file and ...
5
votes
3answers
73 views

How to undo changes in the commands-history?

In UNIX systems you can press top and bottom arrows to navigate through the previous commands. This is extremely handy. Sometimes, I go up and find a command that I want to use again, but with some ...
2
votes
2answers
33 views

universal help/man command: help builtin partial matches

I found a nice little script which iterates through a couple of manuals for a specific command. As a last resort, it will Google it and open a browser window. Source here: ...
0
votes
2answers
61 views

How to use 3rd variable in BASH for loop?

Good day. I want to parse data of particular columns from several files(aprilPlate.txt, mayPlate.txt, junePlate.txt, julyPlate.txt, augustPlate.txt) using For loop. The data of input files ...
0
votes
2answers
37 views

How to grep from command line for theses multiple strings?

I need to run a command to grep one of these strings from command line as web host disabled account to run website from browser until virus files are removed and I managed to collect few strings that ...
6
votes
2answers
33 views

How to check from bash if package exists in debian

I would like to make a installation bash script, where I would like to install mysql server. On linux mint I had followed code: apt-get -y --force-yes install mysql-server-5.6 but I installed new ...
1
vote
1answer
29 views

How to write a regex to look for strings with fixed length with at least one occurrence of a character

I've been doing some reading on regular expressions and thought I had everything covered, until recently. I've had to filter out all strings of length 5 which end with the letter t and contain at ...
1
vote
1answer
34 views

Script executes differently if run from udev

I'm having an issue with a script that seems really weird; it appears to stop executing prematurely when run from udev, but not when I run it manually from the command line. I've tried troubleshooting ...
0
votes
1answer
24 views

How to execute several lines into a .txt

I am using SSH; In a folder I have the next files: -rwxrwxr-x 1 german german 48 Apr 29 10:45 prueba.txt -rwxrwxr-x 1 german german 23 Apr 29 10:43 script1.sh -rwxrwxr-x 1 german german 23 Apr ...
0
votes
1answer
37 views

Script for update

I need your help in a script used for update : OLD="int 10" NEW="int 20" i=0 DPATH="/home" for f in $DPATH do sed -i "s/$OLD/$NEW/g" $f let i++ echo "modified:" $f done what i need ...
3
votes
2answers
114 views

kill: SIGSTOP: invalid signal specification error in bash script

When I use kill on command line it works. kill -SIGSTOP 1234 But if I use in bash script file I get this error: kill: SIGSTOP: invalid signal specification sh file is #!/bin/sh kill -SIGSTOP ...
1
vote
2answers
32 views

Dynamically create array in bash with variables as array name

This has been asked several times, but none of the methods work. I would like to dynamically create arrays with array names taken from the variables. So lets start with just one array for now: ...
0
votes
1answer
16 views

How to search for just new data and upload to mysql table,

I'm having a blonde moment. Problem Statement: So I have some timestamped data in a file which constantly at arbitrary intervals gets updated, and I just want to filter out data for the previous full ...
1
vote
2answers
32 views

How can I properly use the 'sed' s command in this particular scenario

There's a very simple question that's been bugging me about the sed command. Reading the documentation about this command has left me confused (mostly because English isn't my primary language). So, ...
2
votes
1answer
39 views

Execute commands from history that match regex or grep

I was wondering if its possible to execute commands from history that match a certain regex? I know you can do something like fc 232 248 And it will go into your history and then do revisions ...
0
votes
1answer
46 views

AWK is throwing an error “unexpected newline or end of string”

My Bash script: declare -a lang=('english' 'spainsh') sms="Free msg: Due to upgrades on apps you’ll need a new version by yyyy/mm/dd to app running. Visit a store or go to" url="google.com/UA2392 ...
0
votes
2answers
51 views

How to extract unknown arguments within a shell script?

I have a shell script that accepts a variety of options, some with arguments, some without, some short, some long. It should handle some of these options itself and pass on the rest it does not know ...
1
vote
1answer
42 views

How can I prepending a character for every output of a command?

I'm running commands which I want to specifically group them by every command, as shown in the example below. Tried printing with echo -e '| $line' but it only affects commands that output the text ...
3
votes
1answer
148 views

prevent a command from sending both stdout & stderr to any terminal or file [duplicate]

I would like to prevent my program from sending stdout and stderr to any terminals, files or devices. For this, I have three command crossing my mind, but I cannot distinguish their differences. Could ...