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

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1
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1answer
79 views

Loop over lines of file, partition file and classify each partition

In the following I've put up my code for iterating over lines of a file in order to collect data within a segment from the file in following fashion: Illustration for understanding procedure: segL ...
0
votes
1answer
53 views

bash script locked at if statement when executed

I am no expert with bash scripting. I am trying to understand why a bash script seems to stop its execution at an if statement. I have added echo statements in the scripts. I have a first batch ...
1
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3answers
105 views

Pipe output of one command to two others [duplicate]

I need to pipe the output of one command to two other commands. cat filename.txt | tail -n 1 cat filename.txt | wc -l Since the file is huge I want to avoid reading it twice. I checked tee command ...
6
votes
4answers
3k views

Bash, execute command after invoking a new shell

I am trying to make a script like this: #!/bin/bash sudo -s something... When I execute it, I get a new shell but something is executed only when I exit the shell created by sudo -s, not inside it. ...
1
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4answers
791 views

How to extract column name (header) from a CSV file which contains the max value in a row?

I am trying to extract the column name with the maximum value in each row using bash script i.e., the column header value or the value from the same column in the first row. I am using the following ...
0
votes
2answers
80 views

sum of all packets in pcap files

I'm trying to make a simple bash script to calculate packets captured in pcap files, I used tcpdump to get packets in each pcap file and add them using a bash script but it doesnt seem to work. ...
2
votes
2answers
712 views

Merge two-columns files into one file

I have a bunch of files (file1, file2,file3, ...) with two columns. For example, file1 looks like: 0.12 0 0.32 0 0.42 1 0.23 0 and file2 looks like: 0.34 1 0.55 1 0.31 1 0.99 0 I wonder how to ...
0
votes
1answer
370 views

Save command string into bash variable

I'm running a command like so, with the $OUTPUT variable saving the results of the command. But I also want to save the command itself to a variable for inclusion in a status email. OUTPUT=$(php -f ...
0
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1answer
218 views

Loop commands to network daemon?

I'd like to feed a network daemon using a loop! To be more specific: There is a network daemon listening on localhost:portx. The daemon expects me to guess a PIN between 0000 - 9999. I want to use ...
-1
votes
2answers
525 views

Create shell script to remove certain files from specified directories

I am looking to create a simple script that does the following: cd /specified/directory cd into child directory only if it has a 4 digit name e.g 1234 rm -r all files that begin with letter P rm -r ...
0
votes
1answer
213 views

Bash script strange behavior - script does not act as manual commands

So, this is strange. When I manually run commands it all works fine, but when I run a script with identical commands, I get strange error output. This is what I run: lxc list; for elem in ...
2
votes
0answers
31 views

Sed is unable to copy temporary file to original file [duplicate]

My aim is to edit the file (whose owner is user1) using a script where user2 doesn't have permission to directly edit the file but it should be edited when executed through script by user2. So I set ...
-1
votes
1answer
185 views

How to rename or delete an alias permanently from system?

I have created one alias in my system, printf "%s\n" "alias shh='sqlplus hfdora/hfdora@hfd2" >> ~/.kshrc Now, I want to change the alias name from shh2 to shh Also, how to delete other ...
3
votes
2answers
1k views

Call a script for another script, but don't exit the parent if the child calls exit

first.sh: #! /bin/ksh echo "prova" . ./second.sh echo "ho lanciato il secondo" . ./third.sh echo "ho lanciato il terzo" second.sh: echo "sono nel secondo script" dosomething1 exit $? If ...
5
votes
4answers
942 views

Add path to $PATH if not already in $PATH [duplicate]

I need to add a path in a bash script, but it may be executed several times: export PATH=${OPENSHIFT_HOMEDIR}/app-root/runtime/bin/:${PATH} I don't want that path to be added over and over. How can ...
0
votes
1answer
748 views

sftp to use password stored in a parameter file

Is it possible to to connect two servers through sftp with a batch of commands and where the authenticating password needs to be read from a file (where it is stored previously)? I am new in the UNIX ...
0
votes
1answer
17 views

Command Run Differently Depending on How Logged In?

Is there a way to have one command run differently, depending on the manner in which one is logged into the session launching it? Basically, we have a command that when run, launches vim to display ...
1
vote
2answers
113 views

Returning a variable from a function [closed]

I have the Linux script shown below. I can get it to return from the method decrypt nothing which I need to unzip a file. The method decrypt sends a string with the name of a zip file. Please give ...
1
vote
3answers
182 views

How can I un-write protect file made by tee?

I have a small program and I want to ensure that it works on both write protected files and un-write protected files. So, instead of using echo $text > $file or echo $text >> $file, I am ...
-9
votes
1answer
196 views

replace the the first line of all .sh files in a folder

Create list of all .sh files in current folder. Check first line of each file in this list and if file starts with #!/bin/sh then replace that with #!/bin/bash. Only modify files that have #!/bin/sh, ...
-4
votes
1answer
137 views

Find the number of files with sizes

Find the number of files with sizes > 100KB in /, /bin, /usr, /usr/bin and /usr/sbin directories and output them in a two column format with the name of the directory and the number of files.
1
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3answers
90 views

permissions of script to change permissions?

I have a VMWare VM that directly accesses some disks. In order to run (without running vmware as su which has its own problems) I need to change the ownership of the devices. I've done this manually ...
0
votes
1answer
37 views

Find MAPISend syntax and Replace with BLAT syntax

My MAPISend code seems to have kicked the bucket so now I am trying to replace over 1,500 MAPISend lines with BLAT. Is there a way to search through my scripts and find the MAPISend syntax: ...
3
votes
2answers
371 views

Embed “cat file” in CURL data

I would like to cat the contents of a file.txt and use this as part of the --data field in my curl query. I tried: curl ... --data '{ "file_content":[" $(cat file.txt) ", ...]}"' ... but that ...
2
votes
2answers
918 views

Execute CURL command only once in script?

To explain a little, I am currently monitoring a folder for any changes and when changes are detected it simply uploads the detected files to my server via rsync. This is working without any issues : ...
1
vote
2answers
46 views

Else not Executing

In my script, I transform data to a more readable format. But I am having an issue. If no arguments are typed, just the script, I want it to come back "Please enter a filename" which I have done. But ...
1
vote
2answers
81 views

where should I modify the given shell script?

This is my input: #!/bin/bash #Example of menu programs clear echo "*******************" echo "1.Date" echo "2.List of users" echo "3.Open a file" echo "4.delete a file" echo "5.Exit" echo "Enter a ...
1
vote
2answers
320 views

Remove lines from CSV file if the second column is in a word list

I have found a long list of free email providers that I want to remove from my email lists - https://gist.github.com/tbrianjones/5992856 Below are two commands I currently use that do the same job ...
3
votes
1answer
55 views

Generate a large number of the same byte [duplicate]

I'm generating a binary file as test data for a piece of software. The test data should consist of a long array of the same byte. If it was a zero byte I would use /dev/zero. Is there a command to ...
1
vote
3answers
75 views

script for copying directories with particular increment

I have directories which are named as 0.1, 0.15,0.2, 0.25, 0.3,0.35 and so on. Now I want to copy directories at particular increments say of 0.1 together to a separate directory. Say directories ...
0
votes
2answers
623 views

Shell Script: Sending input to background process

I am using the following script to watch a folder, and if the size changes and a file doesn't exist, it runs a script. #!/usr/bin/sh SCRIPT="dim_import/xdir" while true; do size=$(du -s ...
0
votes
1answer
29 views

Determine the tmux session a shell session belongs to?

tmux provides a number of commands in the shell such as rename-session which operate on the session that the invoking shell belongs to. It also provides commands like list-clients which list out the ...
0
votes
3answers
472 views

How to rename all files with special characters and spaces in a directory?

How can i rename all the files in a specific directory where the files contains blanks spaces and special characters ($ and @) in their names? I tried the rename command as follows to replace all the ...
1
vote
4answers
270 views

How to move all files (excluding sub-directories) from one directory to another?

How do you move all the files (excluding sub-directories) from one directory to another. I'd prefer if the solution used just basic shell scripting.
2
votes
1answer
280 views

SSH command not exiting properly [closed]

I wrote a script that SSH to remote servers in loop and run a command, it gets hung after running on last server.Here is my loop script - cat server | while read serName do ...
1
vote
1answer
77 views

How to make awk work in a while loop

input.txt: /usr/dir1/file1 /usr/dir1/file2 /usr/dir2/file4 /usr/dir3/file5 Script: cat input.txt |while read FILENAME do nawk '{print $1}' ${FILENAME} >> output.txt done Expected output: all ...
0
votes
1answer
243 views

load bash comands from file one per line and execute them for each file in a directory

I'm trying to write a bash queue which will be able to load command sets from a file and then execute each over a set of files. The prepared file should serve as a template for execution in manual ...
3
votes
1answer
44 views

Condition on finding a file

I'm trying to write a script which looks for a file and if it is found, saves the full path to a variable. Current version: if [[ -n FOUND_PATH=$(find "$PATH" -name "file.exe") ]]; then echo ...
0
votes
0answers
16 views

Accessing HTML pages through command line for scripting [duplicate]

There is a web page that I usually do the same thing over and over on. Click a button, enter some text and that's it. Is there any program that allows me to interface with a webpage with a couple of ...
3
votes
2answers
49 views

Setting variable with default value behaves differently when preceding a command?

Setting a variable with a fallback default value works...as long as we're using the variable in a subsequent command: $ unset APP_ENV $ echo $APP_ENV $ APP_ENV="${APP_ENV:-production}"; echo ...
1
vote
2answers
106 views

Remove x lines before and y lines after nth line (which matches a pattern) in a file

I'm trying to remove a four line block from a text file if the second line matches the Regex N+. The text file is composed of many repeating 4 line formats, ie: @HEADER1 ACTGCNNNT + 583@#!NMY ...
0
votes
4answers
101 views

Excluding specific lines from being redirected [closed]

Suppose I am executing a script like this: /a/b/c/script.sh >> abc.log This means that all the contents/execution of script will be re-directed to abc.log. If I want a particular line inside ...
0
votes
1answer
88 views

Redirect stdin for multiple shell functions [closed]

I'm surprised nobody has asked this before - maybe I'm just that dumb? How to I force this script to do what I intended? #!/bin/bash function One() { IFS='' read -r -n1 CHAR echo "One: '$CHAR'" ...
0
votes
1answer
63 views

Calculate swap values dynamically

Can someone please let me know if the following commands should work as I am not sure and am getting error? Just to let you know that I am using this in one of my nagios scripts: ## GET SWAP Warning ...
2
votes
2answers
69 views

How to make this loop Ctrl+C-interruptible?

# wait for host to become online while true; do ping host -c 1 -w 3 > /dev/null && break; sleep 1 done When I press Ctrl+C, the ping receives it and exits with exit code 1 (the ...
0
votes
3answers
124 views

Best way to obfuscate AIX script

What is the best way to obfuscate a shell script in AIX? The problem is that as a shared user, I would like that others don't know the code.
1
vote
3answers
85 views

Random sampling and outputting the largest value

I have a fairly large data set ~500 million rows. The data set looks like below. Col 1 is float number, col 2 is mac id(device id) 1616.93,ac:22:0b:a6:22:c3 2872.32,c0:bd:d1:36:bb:49 ...
1
vote
2answers
81 views

Matching “keyword value” pairs from semi-structured input

On occasion I get output from a command that includes "key value" pairs, with possibly more than one pair per line. As a repeatable example, consider the command ip addr show dev eth0: ip addr show ...
1
vote
1answer
2k views

How can I use multiple if statement inside another if statement of a awk program?

I have a CSV File and I want to have multiple checks to retrieve the data from the CSV file. I have the following conditions which needs to be taken care of and I am trying to use awk in a shell ...
0
votes
2answers
211 views

Telnet check in bash script

I want to run the following commands in bash script form in Solaris 10: $ telnet localhost 25 debug quit How do I handle this?