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

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2
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2answers
1k views

Is there a GUI debugger for shell scripts

Debugging bash scripts on command line is complicated. Is there a good GUI based debugger available for debugging bash scripts?
3
votes
1answer
524 views

if else statement in one line using && and ||

I would like to know if these 2 ways are equivalent: First: #!/bin/bash if [ -x $FILE ] then echo "You have execution permission to a "$FILE"" else echo "You don't have execution permission to a ...
1
vote
0answers
61 views

How do I replace symlinks in a path with their target within a script? [closed]

I want to extract part of a file path up to a symlink, use readlink to find the path to the link target, and then replace the link name with the actual path. This has to be done within a script. For ...
-3
votes
1answer
177 views

how to select specific range of line & count the specific occurence of the first charcter w.r.t. each unique second charcter? [closed]

Hi I have a file like this : #0 0:() 1b:cg*b 1c 0:cg xe #4 0:() 0b:cg*b xc 0:cg 1e #8 0:() 0b:cg*b xc 0:cg xe #12 1b:cg*b xc 0:cg 0e #16 xb:cg*b 1c xe #20 1:() xb:cg*b xc 1:cg 1e #24 x:() xb:cg*b xc ...
0
votes
0answers
29 views

Overlapping of cron instance

While searching for a solution to synchronize cron (i.e. only one instance of cron run at at time). I found the solution, given below, on StackExchange. #!/bin/sh LOCK=/var/tmp/mylock if [ -f $LOCK ...
1
vote
5answers
1k views

Copying files with a specific pattern

I am trying to copy files from one location to another and given below are some sample ones: aaa_bbb_ccc_ddd_cost_code_20140330.gz aaa_bbb_ccc_ddd_revenue_zone_20140329.gz ...
1
vote
1answer
54 views

Delete a matching line in a file doesn't work

So, I have this piece of a code: while read line do if [ $line = $maddr ] ; then sed -i '/${maddr}/d' mailinglist found=true ...
0
votes
0answers
23 views

renaming files in sequential order [duplicate]

I have following files SSt12.precip.374.sub.climatology.ctl SSt12.precip.2874.sub.climatology.ctl SSt12.precip.3764.sub.climatology.ctl SSt12.precip.6774.sub.climatology.ctl I want to rename as ...
4
votes
1answer
52 views

Memory consumption of a script

Is there way to check the memory (physical & virtual) consumption of a script, of course in the moment of its execution. Calculating the used memory minus the used memory before and after the ...
1
vote
0answers
63 views

Why below script is not able to find and delete files [closed]

Why below find command does not find and delete files ? I am launching it like this ./script.sh 1 MYFOLDER days_period=$1 myuser=$(whoami) folder_prefix=$2 LOGS_DIR=~/$folder_prefix/logs if [ $# ...
1
vote
1answer
175 views

Unreadable backup directory on a USB drive

The title pretty much sums it up. I was editing a script I wrote some time ago to automatically backup the contents of my Raspberry Pi SD card, and in the course of editing, I missed a "/", and so ...
0
votes
2answers
1k views

How to run a command with a hidden password

I need to run a curl command that accesses a website that another person has the password to. e.g. curl --basic --user myfriendsname:friendspassword http://www.updateinfo.com I need a way where I ...
0
votes
0answers
145 views

TAR not excluding directories with date pattern

I've written this small script: #!/bin/bash TODAY=`date --rfc-3339=date` CHECKDATE=`date --date "2 days ago" --rfc-3339=date` FILENAME=$TODAY-package.tar tar cvf $FILENAME --no-recursion ...
1
vote
1answer
67 views

Problem in using user defined variable in a script

The following is a simple script, named myscript, that I wrote in order to run a command. dcmpath='$HOME/Data' dcmfile='IM1' dcm2nii $dcmpath/$dcmfile Unfortunately, bash does not recognize the ...
2
votes
3answers
107 views

Script needs to read echoed line

So, I need to write a Bourne-shell script, where my script has to work with the line, that was just echoed to stdout - e.g.: echo *something* | myscript.sh [parametres...] This may be a basic ...
3
votes
1answer
143 views

Difference between “.” and “./” while setting the environment variables using export? [duplicate]

Please excuse me if I am not clear while asking questions. I will try my best to be very clear while asking questions. While learning Embedded Linux, we are setting an environment for our project. ...
8
votes
2answers
1k views

Check bash/shell script dependencies

Is there a method/command to check for the dependencies of a bash script? In other words, a response to this question : Which libraries should a user install to run the script? I can do this ...
2
votes
2answers
118 views

Grabbing keyboard control in shell script

I have a certain shell (zsh) script which reads one character at a time and performs an action afterwards. In the shell, this is realized by "read -k" in a loop. I want to execute the script as a ...
2
votes
2answers
280 views

Killing background process in bash script when exiting the script

I have a script that tail a file while displaying a clock in the top right corner. I took the clock part from the internet, and it works ok. The entire script is something like (I simplified): while ...
1
vote
2answers
143 views

Create file with specific formatting from directory contents

I am using Solaris and csh. In $home/test there are five files: a.txt, b.txt, c.txt, d.txt and e.txt. If I run % find $home/test/ -type f -print > ../filenames.txt that file will look like: ...
1
vote
1answer
95 views

observing script execution with monit script seems to ignore pipes

I want to have a bash command running in the background and being watched by monit. To get the PID of this process, I found this script on the web and I modified it to fit my commands: (named sdr.sh) ...
3
votes
2answers
63 views

Trigger job only once and only when load is low

I'd like have automatic update of my gtags, but only when the system is idle. To achieve this, I'm using iupdate to watch over the interesting parts of my source folder. But I have a problem with the ...
4
votes
1answer
352 views

Run script after desktop loads

I'm running a script that changes files and installs things and what not on a SUSE computer. One of the scripts that gets run with my script, reboots the computer and when the computer loads back up ...
9
votes
3answers
12k views

Passing named arguments to shell scripts

Is there any easy way to pass (receive) named parameters to a shell script? For example, my_script -p_out '/some/path' -arg_1 '5' And inside my_script.sh receive them as: # I believe this ...
1
vote
0answers
88 views

Cron job running but not establishing tunnel

I have a script which establishes a reverse tunnel on an endpoint HostB. It looks like this: cat tun.sh #!/usr/bin/env bash # Test code /usr/bin/ssh -V 1> /home/userA/bin/tun.stdout 2> ...
1
vote
3answers
2k views

Bash script for automatic tar backup of chosen files and directories

Within a given directory in linux environment, I need to pick all files modified after a certain date (let's say 7 days) as well as all directories (only in root directory, hence non recursively) ...
1
vote
1answer
48 views

check if genisoimage is succesful

I use a script to convert all VIDEO_TS directories to .ISO. How can I check if genisoimage is actually converting it instead of it failling and converting the next folder? After conversion I have a ...
24
votes
2answers
1k views

What does “${-#*i}” != “$-” mean?

In /etc/profile I see this: for i in /etc/profile.d/*.sh ; do if [ -r "$i" ]; then if [ "${-#*i}" != "$-" ]; then . "$i" else . "$i" >/dev/null 2>&1 ...
1
vote
3answers
316 views

Redirect output of a command to two different files [duplicate]

Redirect output of a command to two different files I know I can use tee, but I dont want the output to be printed on the screen I want them to be printed only on the file example : ls > pk.txt ...
1
vote
2answers
117 views

How to properly launch a program and make possible to redirect its running output (stdout and stderr) at a later stage?

The problem is quite simple: I find useful to have the possibility to switch on (and off) the output of some running program in each moment I need. To be more precise I want to be free to redirect ...
3
votes
4answers
351 views

dd remove range of bytes

Given this file $ cat hello.txt hello doge world I would like to remove a range of bytes to end up with this $ cat hello.txt heorld I would like to do this with dd if possible. The reason is ...
0
votes
1answer
351 views

Using Fifo hang script

out="$katalog/out" # wyjscie fifo="$katalog/fifo" # wejscie mkfifo $fifo touch $out [...] #k ./a.out <$fifo >$out & pid=$! [...] # get input line by line loop start echo "$liniain" >> ...
2
votes
0answers
149 views

Why is my inotifywait loop exiting after removing some subdirectories?

i have the following bash script: #!/bin/sh dir1=/source/dir/path/ while inotifywait -qqre modify "$dir1"; do rm -r /destination/dir/path find /source/dir/path/ -name .svn -exec rm -rf '{}' \; ...
0
votes
1answer
375 views

Creating MySQL database and user without password

I am building a set of bash scripts which basically prepare apache virtual hosts, git repositories and other stuff on a cloud server. So far so good, everything is working, but a big problem occurred: ...
5
votes
2answers
468 views

Why doesn't my loop over the output of ls work?

I am trying to feed Directory names into a for loop. My code is as follows: td='/Test/TopDir/' cd "$td" for x in $(ls -d */ | cut -f1 -d'/'); do echo x=$x done The top directory I run this on ...
2
votes
1answer
130 views

cut slice of file based on time when lines are written

i have a process running always with logging file could reach up to 5 giga, sometime i have to take slice of this log based on interval of time (usually i used dd). is there any command in linux to ...
0
votes
2answers
42 views

FTPing to a remote directory

I need to connect to this ftp http://cdiac.ornl.gov/ftp/ndp026b/ and download the files. I did ftp http://cdiac.ornl.gov/ftp/ndp026b/ and it took the ftp prompt but once I entering commands for ...
0
votes
1answer
143 views

What is the format of the data that must be fed to the freetds tool bsqldb?

I need help figuring out how to input my data to bsqldb. I have been looking for a manual or some examples or tutorial but I cant find anything online beside its command line help. I am planning to ...
0
votes
2answers
82 views

Use xdotool in a telnet session

I have to simulate key presses in a telnet session, and everything has to be invoked by a shell script. #!/bin/sh telnet 192.168.1.14 50000 xdotool type "404" However, once the telnet session ...
12
votes
2answers
3k views

Simplest way to comment/uncomment certain lines using command line

Is there a way to comment/uncomment a shell/config/ruby script using command line? for example: $ comment 14-18 bla.conf $ uncomment 14-18 bla.conf this would add or remove # sign on bla.conf on ...
1
vote
1answer
188 views

can't get hello world shell script to run in FreeBSD

Server is running FreeBSD 9.2. Using vim, I wrote the following script called hello: #!/bin/sh echo "hello world" Then I set it as executable: >chmod 755 hello Then I tried to run it from ...
1
vote
3answers
5k 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
1answer
1k views

wget a file, logging the output and showing the output on prompt

In a bash script, I need to download a file from the web, for doing it i use wget command. I would log the output of wget command, and at "the same time" having the output prompting on terminal. I ...
1
vote
1answer
685 views

apt-get script to update upgrade dist-upgrade clean and autoremove

I wrote this script, #!/bin/bash # if not root, run as root if (( $EUID != 0 )); then sudo /home/jb/bash/update.sh exit fi apt-get update apt-get -y upgrade apt-get -y dist-upgrade apt-get ...
2
votes
2answers
188 views

Sed? Stripping all formatting, i.e line breaks and whitespaces, from a report text file, while masking out certain pieces

I am working on a project in which I need to remove all formatting from a text file including whitespaces and line breaks, then replace any colons with pipes. I've made some headway but I cannot find ...
7
votes
5answers
432 views

List out strings which are substrings of other strings in the list

I have a list of names like so: dog_bone dog_collar dragon cool_dragon lion lion_trainer dog I need to extract out names that appear in other names like so: dragon lion dog I looked through the ...
1
vote
3answers
108 views

Bash Script not deterministic in performing actions

I have a bash script which I invoke on system boot (Ubuntu 10.04) "Startup Applications". script: #!/bin/sh APP1='/home/ipc-display/development/projects/display-mgmt' ...
0
votes
1answer
84 views

Please explain the Awk script provided below

Can anyone please expain me step by step below AWK script written. I have the below code written in my script to format the flat file data. Just wanted to understand so that i can reuse -- I am not a ...
0
votes
2answers
4k views

Bash script returns “command not found” when outside the source folder

under my directory, /home/lucas/bin I have the following script term_multiscreen: [lucas@lucas-ThinkPad-W520]~$ sudo cat bin/term_multiscreen #!/bin/bash # Initializes ...
1
vote
4answers
1k views

What does “while test $# -gt 0” do?

I'm trying to create a function and believe I found a good working example but I don't understand all the logic behind it. More specifically, on the "while" line, could someone explain what test is ...