Questions about shell scripts, executable files that are interpreted by a shell (bash, zsh, etc.).

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2
votes
3answers
64 views

waiting for network in a bash script

I'm running a script that relies on network being up and a network share be mounted. The script runs on login (which happens automatically after boot). The problem is that by the time the script runs, ...
3
votes
0answers
18 views

Get notified from avahi

After looking for a zero-conf browser valid implementation I realised that inside my linux machine (ubuntu) I already have avahi and typing: avahi-browse -alr I get a complete list of all devices ...
8
votes
6answers
489 views

How can I test if a variable is empty or contains only spaces?

The following bash syntax verifies if param isn't empty: [[ ! -z $param ]] For example: param="" [[ ! -z $param ]] && echo "I am not zero" No output and its fine. But when param ...
0
votes
2answers
122 views

Unix Shell Scripting output to an Excel File

I have a Shell script with Multiple SQL statements like this: select Count(*) from Emp where date= current_date-1; After executing the Shell script i need a MS excel file to be create with Column ...
2
votes
3answers
109 views

Count files in a directory by extension

For the purpose of testing, I'd like count how many images files are inside a directory, separating each image file type by file extension (jpg="yes". This because later it will be useful for another ...
1
vote
1answer
31 views

Make some fields required in dialog

The script below creates a dialog box. The user can press Enter at any time, and then the script continues. I need to block the Enter key to ensure that the user fills all the fields. How can I do ...
2
votes
0answers
116 views

Running shell script inside with vagrant provision

I have setup a vagrant box using precise64 (ubuntu 14.04) and installed packages needed for octopress. I can ssh into the vagrant box and generate posts and run preview for my octopress site. Now I ...
4
votes
1answer
120 views

Proper way to distribute shell scripts

What is the most proper way to distribute shell scripts, if behaviours of shells can be modified by set and thus are unpredictable? For example, rm *.txt wouldn't be executed as expected on the ...
2
votes
1answer
51 views

Arrow key/Enter menu

I need help finding out how to possibly create a menu in a shell script that will display 3 options that a user will use the arrows keys to move the highlight cursor and press enter to select one. If ...
1
vote
1answer
35 views

bash script not being run by cron [duplicate]

I have a very simple bash script that runs flawlessly when I do ./removeOldBackup.sh or sh /home/myusername/backup/removeOldBackup.sh but when I add it to crontab like * * * * * sh ...
1
vote
0answers
27 views

Trap not trapping SIGTSTP

I have a script that keeps displaying the login prompt: #!/bin/bash trap '' 2 20 while true; do login done This is part of a bigger project so please don't tell me to just use the system login ...
4
votes
2answers
38 views

How to sort a collection of lines from different files?

I want to sort second line in each file by second column, and also print name of the corresponding file. I am doing it like this - rm tmp; for filename in file*; do num=`head -2 $filename | tail ...
2
votes
2answers
92 views

How to clear the input in Bash

I have a bash script that is reading quite a bit of data /dev/random. I need the user to type randomly to seed the random daemon. However once the script completes everything typed will get dumped to ...
2
votes
1answer
59 views

Memory buffer in a bash script

I have recently finished a script that will ask for a hostname and automatically take the argument of the function and ssh into one of my work servers. Here is a copy of my script: #!/bin/bash echo ...
6
votes
7answers
242 views

Count total number of lines before/after a pattern match

I am having a long list of IP addresses, which are not in sequence. I need to find how many IP addresses are there before/after a particular IP address. How can I achieve this?
2
votes
0answers
39 views

Shell scripts for the database logs

The actual log file will be like this $ cat file1.log time=2014-07-23 23:56:28 GMT, user=[unknown], db=[unknown], host= pid=28254 LOG: time=2014-07-23 23:56:28 GMT, user=portalman, db=ss, ...
3
votes
3answers
58 views

How to read a text file line by line which is not constant in shell scripting

I need to read a text file line by line and the lines are not constant it may vary.For example $ cat file1.txt syntax error at or near "?" at character 1 syntax error at or near "[" at character 1 ...
8
votes
3answers
479 views

Creating a Bash script that will execute a program and if it exits without crashing, will run it again

I'd like to know the easiest way of creating a bash script that will run an app in MacOSX (it's a UNIX based system so I assumed this was the right place). wait for the program to exit. If the exit ...
6
votes
2answers
166 views

Is there a way to convert a zip to a tar without extracting it to the filesystem?

Is there a way to convert a zip archive to a tar archive without extracting to a temporary directory first? (and without writing my own implementation of tar or unzip)
4
votes
6answers
80 views

reading a list of lines from a file writing output to a utility

I have a file with a list of lines I want to read from another file. I want to output those lines to a utility (grep) that lets me read the entire line and pull information from it. The file with the ...
3
votes
2answers
71 views

fdupes - delete files after comparing two directories

I'm currently trying to solve an issue using fdupes. I'd like to compare two folders with each other, and afterwards delete all duplicate files within one of these directories. Example: Files are ...
2
votes
1answer
50 views

How to set parameter zero ($0) while executing a script?

I can manipulate positional parameters using shift or set -- while a script is interpreted. How can I change $0?
1
vote
2answers
190 views

How to iterate through multiple file extension without caring about case sensitivity?

I've seen various topics on how to iterate through multiple file extensions but in most case, the list is defined. example: for file in ${arg}/**/*.{txt,h,py} do .... done As can be seen, ...
5
votes
3answers
202 views

How to iterate through a list of files with spaces that is sorted (case insensitive)?

I am doing this in OSX which uses bash but obviously, not all bash conventions are used so hopefully your suggestion is available to me :) I have the following files fun bar1.txt Foo bar2.tXT ...
-4
votes
2answers
118 views

“bash: [: : integer expression expected” [closed]

I want this function to return one random word if there aren't any command-line arguments. I am modifying linuxconfig.org's random-word generator to run even when #$ -ne 1. function random-word { ...
3
votes
1answer
58 views

How do I use sudo to run multiple commands as another user within a portion of a script?

I'm trying to run the following: if [! -f .owner ]; then creator=$(whoami) sudo -u appuser ksh echo "$creator" >> .owner mkdir test1 test2 test3 exit fi However, the ...
2
votes
1answer
47 views

Fetching Remote Windows System Information From Linux Server

I need a script/command that would fetch Windows System Information (Host Name,User Name, Domain, OS Info, Hardware Info, Memory Info, processor Info, etc) by running it on a Linux Server (RHEL 6.5 ...
6
votes
3answers
374 views

How you stop 'wget' after it gets a 404?

If you use brace expansion with wget, you can fetch sequentially-numbered images with ease: $ wget 'http://www.iqandreas.com/sample-images/100-100-color/'{90..110}'.jpg' It fetches the first 10 ...
3
votes
1answer
40 views

Triggering Bash Before Killed [closed]

I just made some kind of service code. Check this out: do_start() { while true do if [[ $(pgrep -fl loopsvn.sh | wc -l) -gt 2 ]]; then echo "Already use by another ...
-1
votes
1answer
26 views

add groups from external file

I want to write a script which add groups to the system, specified in groups.txt file. content of groups.txt : group01 : computer group02 : electronics group03 : IT . ...
12
votes
4answers
639 views

Recursively create directories for all letters

I want to create a directory in such a way that I need to label the directories from a to z. Inside each of these directories, I need to create sub-directories so that they are labelled as aa, ab etc. ...
2
votes
2answers
60 views

Call the script after disconnecting from server

I have a script I made for work that will call a function that takes an argument. I use the arguments to ssh into our servers. My question is: Is there a way to call the method so that if/when I get ...
6
votes
2answers
83 views

Passing arguments from a file to a bash script

I' ve got this situation: ./ ./myscript.sh ./arguments.txt ./test.sh Inside myscript.sh, i have to run the file test.sh, passing to it the arguments contained inside arguments.txt. myscript.sh is: ...
3
votes
2answers
76 views

transfer a file to remote dir only if doesn't exist without replacing

I'm using CentOS linux. In one line cmd, that returns 0 if success, non-0 if failure, I need: Transfer a file to a remote server. Don't transfer the file if filename exists in remote server ...
4
votes
6answers
188 views

Finding the number of time a particular number in a file where range also specified

I have a file with numbers separated by ,(comma). In between it also contains a number range like 300-400. Say for example I have a text file, namely testme.txt which looks like, ...
2
votes
1answer
68 views

Asteriks in filename as wildcard not working [closed]

So I have a folder with many files like 20140720.457812.tmp and I try to count how many lines they have, I tried this: #!/bin/bash lines=`more /folder/20140720*.tmp|wc -l` but I get this error: ...
4
votes
3answers
120 views

Frequency of words in non-English language text: how can I merge singular and plural forms etc.?

I'm sorting French language words in some text files according to frequency with a focus on insight rather than statistical significance. The challenge is about preserving accented characters and ...
1
vote
1answer
64 views

Formatting an external HDD with Bash script

At my workplace we have an external HDD connected to a NAS device (Synology). There is a backup tasks which runs weekly and fills the external HDD after a while. Unfortunately the Linux-based OS of ...
0
votes
0answers
86 views

How to find the cpu and memory usage of a single process in linux

This question is similar to this SO. I wanted to find the CPU and memory utilization for a single process so I decided to use the top -p <$PID> as mentioned in the question. Here is my script. ...
2
votes
1answer
33 views

What do I need in my script to be able to change ownership of a directory structure that belongs to root to the current user running the bash script?

My bash script has the following section: su root -c chown -R smithb:other /export/home/smithb/workspace/rootownsit/ exit The directory rootownsit and its two sub directories were created and is ...
5
votes
1answer
102 views

How to continue a script after it reboots the machine?

I'm writing a shell script in bash. At some point in the script, it detects that the machine needs to be rebooted before continuing. It issues: sudo reboot When the machine comes back up, there ...
0
votes
0answers
24 views

A script to identify whether a file descriptor has gone bad

Problem : I have a server program running which connects to a remote program using TCP sockets. There many of them (say 20). My problem is one of the socket descriptor has gone bad and has recieved ...
2
votes
2answers
76 views

How do you construct a grep & command to match a number of patterns depending on how many are provided at runtime?

I have exported some MS Word documents to plain text and use this function to parse the contents of the .txt files in the current directory: mo1 () { for i in *.txt; do echo "File: $i" grep ...
2
votes
1answer
51 views

How can I get this script file's functions to load without having to source it every time? “command not found” (Bash/scripting basics)

How can I get this script file's functions to load without having to source it every time? I created a file foo with script functions I'd like to run. It's in /usr/bin, which is in the PATH. File ...
1
vote
2answers
135 views

Copy ssh public key to multiple Linux hosts

I am trying to copy .ssh/id_rsa.pub from our central server to multiple servers. I have the following script which I usually use to push changes to the different servers. #!/bin/bash for ip in ...
3
votes
1answer
52 views

Restricted ssh remote execution with arguments

I need to enable remote execution of a shell script on a server, but deny all other access. The script is a toggle that accepts a single parameter (on/off/status). This comes close to answering my ...
12
votes
3answers
517 views

Comparing two strings in Bash

I have the following if block in my bash script: if [ ${PACKAGENAME} -eq kakadu-v6_4-00902C ]; then echo "successfully entered if block!!" fi The script execution is not entering my if block even ...
1
vote
1answer
30 views

Create bash script for wine cmd script

I have installed FIFA09 through wine & it runs great...however i have to manually go to installation directory each time & open the terminal there. Then have to write in two steps: wine cmd ...
2
votes
2answers
79 views

Tmux Split Panes in the same window

I am new to using tmux in scripting and I am attempting to manipulate it so when I run a script I can have multiple screens attached and split in my Putty session, and also have it color coded and ...
2
votes
1answer
62 views

How to terminate a shell script?

I'm working on a supercomputer and have a shell script that will automatically schedule a bunch of jobs for me. Once the script is run, I can terminate manually with Ctrl+C. I was running the script ...