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

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4
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1answer
351 views

Default to “Execute” when double-clicking on a shell script in PCManFM

Is it possible to get an executable to execute by default? What I mean is this. I have an .sh file, which if I click on twice, it will show me this: If I then click Execute, it does the right ...
4
votes
1answer
527 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 ...
4
votes
2answers
1k views

Find files newer than another file within each subdirectory

I have a folder structure like this /Class/Student/Unit/files Each Unit folder contains a file MarkSheet* that I update when I mark a students work. I need a script that tests if the student has ...
4
votes
3answers
1k views

How to output to screen overriding redirection

Is it possible, within a shell script, to write to the screen while STDOUT and STDERR is being redirected? I have a shell script that I want to capture STDOUT and STDERR. The script will run for ...
4
votes
2answers
696 views

Exiting out of an infinite reboot loop in startup (rc.local)

I am creating a startup script (called from rc.local) in Debian Squeeze. The startup script checks for a variable value from a file, decrements the variable and writes it back to the file, then if the ...
4
votes
3answers
803 views

Linux command line that will fail if any standard out is produced

Is there a simple utility which I can pipe output to on Linux that will: Return a success code if there is no output on standard out (and / or standard error). Return a failure code if output is ...
4
votes
2answers
160 views

Dealing with script interruption

I need to iterate over between 120k and 500k files. find handles this well. find $PWD -type f -path "fragments/*.pdbqt" For some reason I want to list the same set of files again, in the same ...
4
votes
1answer
95 views

Transform directory structure

I have the following folder structure root folder |-al2 |- GER.zip |- ENG.zip |-ww |- GER.zip |- ENG.zip and so on. The folder names are random strings. I want to sort the files in ...
4
votes
1answer
727 views

In a script, check if standard input comes from a file or pipe

I know this has been poorly covered previously, but those answers either lack explanation or don't apply. Basically at some point my scripts needs check if a file is specified, if it was it will be ...
4
votes
4answers
7k views

How can I check if mysql is installed using a bash script?

I need to check if mysql is installed from within a bash script. What would be an efficient way of doing that? I thought I could do this: if [ ! -f `which mysql` ] ; then echo "foo" fi But I ...
4
votes
4answers
1k views

script for logging all the stats for a particular process

I want to monitor CPU usage, disk read/write usage for a particular process, say ./myprocess. To monitor CPU top command seems to be a nice option and for read and write iotop seems to be a handy ...
4
votes
5answers
105 views

sudo in non-interactive script

I have a script that executes three functions: A && B && C. Function B needs to be run as a super-user, while A and C doesn't. I have several solutions but neither of these is ...
4
votes
2answers
82 views

Replace string in a file with another where both are saved in variables

I want to replace a string found in a file with another string, but both have a special character (in this example it is a . char) e.g 1.0 and 2.0. So this is the command currently used: sed -i ...
4
votes
1answer
112 views

Is there anything equivalent to getch() in ksh?

I am writing a script in Korn Shell, where at one statement I want something like getch() used in C. I want my while loop to be exited, if it sees that I have pressed ESC in Keyboard. For eg. while ...
4
votes
3answers
949 views

Add text with echo but start with new line if file not empty

I'm trying to create next script echo "#!/bin/sh" >/script echo "del x.txt" >>/script witch is ok if /script file is empty, if not - will append first line to last text #!/bin/sh del ...
4
votes
1answer
154 views

inotifywait - get old and new file name when renaming

I'm looking for a reliable way to detect renaming of files and get both old and new file names. This is what I have so far: COUNTER=0; inotifywait -m --format '%f' -e moved_from,moved_to ./ | while ...
4
votes
6answers
673 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 ...
4
votes
1answer
59 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 ...
4
votes
1answer
171 views

measure amount of data read from /dev/random

background I have written a collection of bash scripts (most of them in German only yet but if you are interested; download the archive not the single scripts) which help users create high-quality ...
4
votes
1answer
2k views

How to strip color codes out of stdout and pipe to file and stdout

I have a program that uses printf with some tput mixed in it and I'd like to pipe the output to stdout as well as a file. I'd prefer to use sed since I don't want any unnecessary dependencies on my ...
4
votes
1answer
276 views

How Can I Automate the Change between a Python Script and a Nohup Python Script?

I have a Raspberry Pi connected to a digital temperature probe, which measures my fermenting beer. A python script reads the temperature every second and prints it to the console, and stores it in a ...
4
votes
2answers
382 views

How can I synchronize processes started in different TMUX panes?

Consider this: tmux split-window -d program1 program2 # this program depends on some side effects produced by program1 In this case, program2 will start before program1 is ready. program1 will send ...
4
votes
2answers
1k views

Get line number in a Bourne shell script

I'd like to be able to print the current line number in a shell script. I know about the $LINENO variable in Bash shells, but it doesn't seem to exist in Bourne shells. Is there any other variable ...
4
votes
1answer
187 views

Discard stdout of a command for t seconds

I am working on some batch scripts involving the following: Run some non-terminating sub-processes (asynchronously) Wait for t seconds Perform other task X for some time Terminate subprocesses ...
4
votes
1answer
129 views

Script for “battery level reminder”

I want to plug in the laptop battery charger when the battery level goes down to 40% and then plug it out when the battery charge level reaches 80%. And for that reason, I need a script that would ...
4
votes
2answers
96 views

Using $ in a password

Lets assume that password of my server is Abcd$1234 I am trying to ftp a file from other server to my server using the following in shell script ftp -inv (IP) << EOF user Username Abcd$1234 ...
4
votes
1answer
236 views

returncode of command in a pipline [duplicate]

The following script runs on Solaris using /bin/ksh and on Linux using /bin/sh cmd | tee -a cmd.log | tail exit $? The output of cmd is saved in a file cmd.log and the last lines are displayed on ...
4
votes
1answer
437 views

output while reading keyboard input

I'm trying to write a script that will ssh into a box, start a processes that needs to be monitored (by a human) for success or failure then move onto the next box and repeat. I've been trying to use ...
4
votes
2answers
935 views

Simple Shell script to log disk space

I'm working on automating collecting disk space on a group of servers. In a standard terminal, if I run: ssh server1 ssh server2 df -h Then I get the output of the command, just fine. ...
4
votes
1answer
1k views

Validate AIX Password for root from script

Looking for a way in a shell script to validate the password for for root on an (AIX) matches a standardized plain text password. This query is similar to another one on this site. I have access to ...
4
votes
2answers
340 views

Script for emulating Windows [Win]+[Arrow] keyboard shortcut

I am running Fedora 14. I would like to (at least partially) emulate the behaviour of Windows when you hit Win+Arrow Key. That is, I would like it to "snap" to the left/right sides of the screen. I ...
4
votes
1answer
46 views

Simple problem, Long read: How to overwrite file residing on ESP at Linux boot

First, foundation. Here is my setup: I have a 64-bit dual-boot system running Windows 7 and Linux Mint 17 Cinnamon. I use rEFInd to graphically choose which system to boot. A little bit about ...
4
votes
1answer
235 views

How to write a shell script to run multiple command in different screen sessions?

My goal is to write a zsh script in order to create multiple screen sessions and run separate commands on each of them. I would also like to check at the beginning of my script if there are any ...
4
votes
2answers
549 views

How do I run a script when I switch between keyboard layouts

I use more than one keyboard layout, and I would like to find a way to run a script when I switch between them. Is this possible? So far, I can assign a shortcut for a script like this: #!/bin/bash ...
4
votes
1answer
813 views

Scoping variables in ksh

In ksh, I have two variables with the same name , one global , other one is local to a function #!/bin/ksh LOG_FILE=lf function exec_script { local LOG_FILE=f print $LOG_FILE } exec_script ...
4
votes
0answers
105 views

How to code shell script with command line arguments like -la [duplicate]

Possible Duplicate: How do I handle switches in a shell script? I know how to deal with simple arguments $1-$9 but I don't know how to code it with such as -la, for example ls -la. Could ...
3
votes
5answers
904 views

Lots of elif, is there a better way?

I have a Bash script that looks like #!/bin/bash # FECHA=`date +%j` if [ $FECHA -eq 40 ] then echo "Esta semana le toca preparar el café a Osvaldo" | mail -s 'Café' mailgroup@somedomain.mx ...
3
votes
7answers
3k views

Problem in splitting a string using awk or cut command

I have a properties file which has a password field (key value pair) PASSWORD=NDhhHcsOBofXUdUzGw5B0Q== I am trying to get the value in my shell script using the awk command password=`awk -F "=" ...
3
votes
2answers
537 views

How to ls without recursive

I am trying to ls some files with a pattern in a directory. I only want to scan the first level not recursive. My script: for i in $(ls $INCOMINGDIR/*$BUSSINESSDATE*) do echo $i; done Above ...
3
votes
5answers
288 views

How do I loop over output from shuf?

If I do gshuf -e $(seq 1 10) in bash it will print the numbers 1 thru 10 in random order. But if I do: a=$(shuf -e $(seq 1 10)) for i in "${a[@]}" do echo $i echo "next" done It prints ...
3
votes
2answers
4k views

Scripting `rm` and `rm -i`

I want to create a script that whenever there are more than three files being removed, it invokes rm -i by default. I know it will go in initialization files but can't seem to get it working. So far: ...
3
votes
2answers
485 views

How does a script/program executes in unix?

I have a doubt about the execution pattern of a unix script. For example a script containing lines: command B function C() { Myscript // Myscript is a script command D } command E and ...
3
votes
6answers
5k views

How to reverse a string made of digit in bash?

What is the best way to turn out digits in number? E.g. $ echo 123 | hook 321 $ echo 12358 | hook 85321
3
votes
5answers
340 views

How can I force a script to use more resources?

I'm running a very time-consuming script which takes many hours to end. Watching top I see that it's only taking 5% of the CPU at best, usually around 3%. Is there any way to force the script to use ...
3
votes
5answers
887 views

What are the special characters to print from a script to move the cursor?

I found that by printing \r from a script the cursor moves to the beginning of the line. What character will move the cursor up one line? Where is a list of these special characters? EDIT: Working ...
3
votes
4answers
4k views

List of servers to check for SSH availability

I have a list of IP address that I need to SSH to and log if I could get to them. I would use a Ping script, but DNS might have already reassigned the address. I do not care about the ones I can't get ...
3
votes
1answer
537 views

Why is 'kill -9' killing browser as well as server?

I sometimes have to use kill -9 as a last resort to kill my rails server. Unfortunately, I have to do that often enough that I wrote a helper function in my bash_profile to do it. If I do it manually ...
3
votes
7answers
624 views

get parts of string using shell script

I have one string as /ip/192.168.0.1/port/8080/ I want to get two separate variables which will contain port and IP like. 192.168.0.1 and 8080 as I know /ip/ and /port/ will be there always I ...
3
votes
2answers
2k views

When sh is a symlink to bash or dash, bash limits itself to POSIX-compliance, so it should be 100% compatible with sh?

From Difference between bash and sh: ABck to the question: If you have /bin/sh as a link to bash, then bash will not behave the same when called as /bin/sh as it does when called as /bin/bash. ...
3
votes
2answers
111 views

How to list only JPEG files from root below using the command line?

I am searching for a method to find only JPEG files/ With my limited knowledge of Linux I came to this point: list all paths that exist from root below with find / pipe the result into next command ...