A script is a sequence of commands or instructions that are executed by an interpreter program rather than compiled into a standalone executable program.

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4
votes
2answers
1k views

Safely exiting while loops in bash

Say I have a bash script that does: while : do foo done I would like to be able to run this script from the console and be able to exit it at an arbitrary time as long as it happens in between ...
2
votes
3answers
220 views

AWK & Bash: Checking that a User's Home is Owned by the User

I'm trying to cycle through /etc/passwd with a single-line command in order to find those users who have a home directory which is not owned by the user, but I'm VERY new to bash programming, and I ...
0
votes
2answers
101 views

How to scrape multiple IP's and add in a script as a variable?

I am trying to add in my script an awk statement or a: if; else; then if eth0:4 is a match then put in eth0:4 IP How would you get the IP in your script as a variable if you have multiple IP's ...
29
votes
3answers
123k views

Pass command line arguments to bash script

I am new to bash script programming. I want to implement a bash script 'deploymLog', which accepts as input one string argument(name). [root@localhost Desktop]# ./deploymLog.sh name here I want to ...
1
vote
1answer
172 views

Displaying “No Results” When AWK Command has no output

I have the following code, thank-you to the people who helped me here awk -F: '{if(system( "[ -d " $6 " ]") == 1) {print "The directory " $6 " does not exist for user " $1 }}' /etc/passwd However, ...
1
vote
1answer
202 views

shell script for date checking between two days

There is date in my file, like 30-apr-2015. How can I compare this with the current date and get notified if they are equal?
0
votes
2answers
110 views

Linux Bash Scripting Issue with Wildcard

I'm having issues with what I imagine should be a simple bash command I'm basically just trying to loop through a bunch of files and get there names `ls ./*.sql` # list all files ...
0
votes
1answer
2k views

Using alias in another script (ksh)

I'm writing a ksh script, and I'd like to use a command define by an alias in my .profile file, in my script. I tried this command in the folder containing my script, and it works. However, in my ...
1
vote
1answer
176 views

Rsync Excludes Folders

I am running a rsync script and I want to exclude certain folders. I know with rsync you have to create a .txt file and add all the excludes in there but I am wondering is it possible to just have a ...
8
votes
2answers
677 views

Command to move a window to all desktops

I'd like to be able to move (pin) an existing window to all desktops using a scriptable command, rather than through the window menu. wmctrl -r <WIN> -t <DESK> will move a window to a ...
3
votes
0answers
48 views

End recording once silence is detected

I've been using something like this up to now: End sox recording once silence is detected But now I'd like for the audio source and recording mechanism to be separate. I can get the source as an ....
0
votes
1answer
74 views

Printing conclusion at the end of script

In this example code I have numbers in the file "list.txt" I wanted to create folders in a specific location "target" for every number in the file "list.txt". In order to do so I used for loop as the ...
1
vote
1answer
82 views

How to change bash script output when the script is running?

I have the following loop which counts from 0 till 99: #!/bin/bash for ((i=0;i<100;i++)); do echo $i sleep 1 done Is there a way to change the result of the output from terminal while ...
1
vote
1answer
74 views

How to move directories based on the output of rhash (CRC32 check of .sfv) with bash/perl?

My idea, is to move the CRC-check OK folders (albums) into a lets say "complete+CRC_OK" folder with a script once per day in cron. I would need to put the rhash command in a loop with number of ...
17
votes
4answers
863 views

How can I implement a circular flow of data among interconnected commands?

I know of two types how commands can be connected with each other: by using a Pipe (putting std-output into std-input of the next command). by using a Tee (splice the output into many outputs)....
4
votes
1answer
349 views

Need to press enter to get prompt after executing udev script

I have set a simple udev rule for my Raspberry Pi (Debian) to automatically mount an USB HDD. It just runs a script which mounts all devices in /etc/fstab since it's the only one I have and I'm going ...
-1
votes
1answer
5k views

Syntax Error: unexpected end of file — Bash script [duplicate]

I am trying to create an spritz app! Everything was working fine, but since yesterday I keep getting this error: ./spritz: line 176: syntax error: unexpected end of file I have checked the script ...
0
votes
1answer
120 views

How I can change all symlink to the new path [duplicate]

Please, I want to change the symlink to the new path My symlink's in this form lrwxrwxrwx. 1 s01 s01 56 Mar 22 13:17 zmjppcxlpq2m.png -> /home/s01/public_html/cgi-bin/uploads/00029/zmjppcxlpq2m ...
10
votes
5answers
7k views

How to remove multiple blank lines from a file?

I have some text-files I use to take notes in - just plain text, usually just using cat >> file. Occasionally I use a blank line or two (just return - the new-line character) to specify a new subject/...
2
votes
1answer
128 views

bash: how to save state on prompt evaluation [duplicate]

I want to put duration of last running command in command prompt, f.ex: user@host$ sleep 360 6m user@host$ Also, I want duration to not show up if it is less than some minimum threshold (say 30 ...
2
votes
1answer
1k views

what are practical uses of stdbuf or nohup?

I have to finish a writeup of a few coreutils commands for a course at the moment, and I can't think of a starting point for a small practical code example that demonstrates the potential uses of ...
0
votes
2answers
138 views

Adding 1 string to end of file, Even when ran multiple times to change MD5

I need to change the md5 of my files, Sometimes once, sometimes multiple times. A friend gave me this script to add a string to the end of the file but i think i may be adding it multiple times when i ...
23
votes
7answers
78k views

Execute remote commands, completely detaching from the ssh connection

I have 2 computers, localpc and remoteserver. I need localpc to execute some commands on remoteserver. One of the things it needs to do is start a backup script that runs for a number of hours. I ...
1
vote
4answers
586 views

bash division of numbers in text file

I have two numbers in test.txt file, I would like a way to divide the second number by the first number and assign the result to a variable or file in a bash script that I can use. I have used awk "NR=...
0
votes
1answer
95 views

User Input Bash Script

I am trying to make a Bash Script that has 4 choices and prompts the user to select an option. Each option corresponds to a Linux Command operation. Can someone give me a bash example on how could ...
6
votes
6answers
251 views

Remove Same Column Values

I have a very big file and I want to remove if the column value is 9. Sample: My file value like this: 1 5 8 3 5 9 5 7 6 9 2 5 7 4 2 9 7 6 3 1 5 9 7 4 1 9 5 7 9 1 I want to delete any columns ...
4
votes
2answers
20k views

Conditional statement, “unary operator expected”

I am having a problem with an example script that is given in the textbook 'Unix and System Administration Handbook'. The script is below... I am receiving an error that states logscript: line 8: [: ...
0
votes
0answers
46 views

Script for auto-starting programs after restart

Is there any script or program to make all open programs auto start after the system restart? Like the one on the mac that gives you the option to reopen all programs after restart or shutdown
9
votes
8answers
689 views

Find duplicate PDF files by content

Some journals generate a different PDF for each download. APS for example stores time and the IP address in the PDF. Or there is a paper version with hyper links and one with text references. How ...
3
votes
2answers
4k views

How to delete old backups based on a date in file name?

I have a daily backups named like this: yyyymmddhhmm.zip // pattern 201503200100.zip // backup from 20. 3. 2015 1:00 I'm trying to create a script that deletes all backups older than 3 days. The ...
2
votes
1answer
57 views

Neutralisation of data from Windows to Unix

I just noticed that other platforms files (Windows) had to cause me many bugs, like here, in my regexes. Mostly, the line ending ^M. There seems to be many ways to do dos2unix, like here described. ...
0
votes
1answer
99 views

Script to Log Shutdowns and Reboots

I am trying to create a script that will run daily as a cronjob and log all shutdowns and reboots. I've come up with this, but the grep seems to be ignored, and the script results in the output of ...
2
votes
2answers
294 views

vim: using a for-loop-iterator-variable in a search pattern

I am trying to use a for loop iterator variable in a vim search pattern to determine for a range of words how man times they occur in a file. What I do so far is: for i in range(1,40) | %s/SiTg//gn | ...
2
votes
2answers
86 views

How to transform string with character codes into quoted form

I have a string like New\x20Folder. Special characters is represented by their codes. I'd like to transform the string into quoted form: "New Folder". The only available tools are bash and bunch of ...
2
votes
1answer
117 views

Updating config files within the script that references them?

I have no problem adding config files to a given script, but automatically updating them is another matter. In this instance I'm providing a few variables to a script, and I'd like the script to be ...
14
votes
4answers
2k views

How to retrieve IP addresses of possible ssh attackers?

I've just cat /var/log/auth.log log and see, that there are many | grep "Failed password for" records. However, there are two possible record types - for valid / invalid user. It complicates my ...
0
votes
2answers
106 views

Why is the suid bit having no effect on a shell or perl script? [duplicate]

As an experiment in playing with the suid bit, I tried writing a script to run apt-get update from a bash script, and then set the suid bit on it, so I could just run ~/update or something. apt-get ...
2
votes
1answer
257 views

Transform .csv into 3 columns and a row

Sample Input: id,Product1,Product2,Product3,Product4 1,0.1,0.3,0.8,0.7 2,0.6,0.7,0.5,0.9 I need output as : id,productname,product_val 1,Product1,0.1 1,Product2,0.3 1,Product3,0.8 1,Product4,0.7 2,...
1
vote
2answers
38 views

Substituting file extensions on a variable

I'd like to do the following : create a .tex and directly show it after compilation with evince, ideally it would be like this: showpdf file.tex so I wrote #!/bin/sh pdflatex $1 && ...
1
vote
2answers
373 views

How to copy only files in a specified directory to another folder

I'm trying to copy only the files from one directory (not including folders or any files in its subfolders) to another location using cp /media/d/folder1/* /home/userA/folder2/. It is copying the ...
3
votes
3answers
3k views

Switch user in a shell script without entering the password

I'm running a shell script using terminal from userA. In the middle of this shell script, I switch to userB user using su, but this asks me for the password of userB and I have to manually enter the ...
1
vote
4answers
107 views

Delete all files in a directory

I have a directory which includes some files and some folders containing other files. I'm trying to remove these files in the main directory without touching the folders or their contents. I'm using ...
-1
votes
1answer
112 views

How to write a auto-completion bash script?

I want to run some functions (which I created in ./.bash_func) in terminal with some files located somewhere. When I type the function and hit Tab Tab I want to list the files located in ./scipts like ...
2
votes
1answer
122 views

Please explain the syntax

Can someone explain the syntax of the following commands? II know what they do but was having a hard time getting the syntax, find / -type f -exec grep -H 'text-to-find-here' {} \; cat access.log | ...
2
votes
2answers
289 views

Is shell parent of all the processes in linux

I have been trying to understand shell scopes and environment in depth. I have been reading about how if we do export VARIABLE=VALUE it will be available in subshell. So I wanted to ask a question I ...
2
votes
1answer
52 views

Copy files that partially matches another files in another location

I have a list of jpeg files in a directory like this (below is just a sample, like the structure is the same but this there are many fo0# sub-folders, not only fo01 and fo01, where each of these ...
3
votes
1answer
810 views

Remove newlines in file names

I have a PHP code that generates the file name on which wget will append its logs. I generated 2000+ files, but the problem is I am having trouble working with them because I had a mistake of putting ...
-1
votes
2answers
62 views

grep to get all the getters from a java file

I have a java file called Friends.java . There are 5 variables and each variable has its own getter. Assume that all the functions below follow standard java standard, i.e public methodName(){ //Some ...
1
vote
2answers
53 views

How do I update the dates (by 30 days) in the files going to that specific location in unix?

How do I update the dates (by 30 days) in the files going to that specific location in unix? Can awk or sed help ? File format is as below - Thomson: xyz Format: 1 Character_set: ASCII8 File_type: ...
0
votes
1answer
438 views

Linux Bash Script Ideas [closed]

I have been given the task of creating a shell script to show my proficiency in scripting. I am really struggling with ideas on what to do. I would like to create something that is relevant and could ...