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

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2answers
829 views

Command/scripts to check the Reverse DNS Lookup time

I am working on a project in which one master communicates with numbers of slaves. For that it has to make connection with hosts in network. But sometimes it hangs. I think that the reason behind is ...
1
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2answers
32 views

Is there a way I can grep recursively over all the files in the current directory to find a pattern and then print it in order of high to low?

So so far, the code looks like this: grep -rc 'Author' $1 It prints out all the files in the directory, which is taken as an argument. However, how would I sort the output (for example): - ...
0
votes
2answers
20 views

Backup script fails with the rsync command's options in a quoted variable

Using: rsync version 3.1.0 protocol version 31; Linux Mint 17 (based on: Ubuntu 14.04.3) In one of my backup Bash scripts, which uses rsync, I put the rsync options in a variable like this: # Set ...
0
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0answers
23 views

Multiple sed commands in a file

I want to save a .txt file to 2 separate .txt files using command placed in a .txt file. I can use sed -e '1,20 w file1' -e '21,$ w file2' input.txt But how would I plac e this command in a file ...
0
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3answers
24 views

How to determine callee function name in a script

to make it short, doing s.th. like -bash$ function tt { echo $0; } -bash$ tt yes, $0 will return -bash BUT how to get the function name called, i.e. tt in this example instead?
1
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2answers
82 views

What do you use when you can't use Bash? [on hold]

I am trying to make a shell script that runs on a widest variety of *nix systems. So, if I wrote a bash script backwards compatible with old versions of the shell, but what if bash wasn't on the ...
1
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1answer
35 views

How while loop execute in the shell script for the FALSE condition?

I tried it with some example but it is not clear to me. FIRST EXAMPLE #!/bin/bash i=0 while [ $i -lt 10 ] do echo "$i" i=`echo "$i + 1" | bc` done output ===> 0,1,2,3,4,5,6,7,8,9 now ...
0
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2answers
26 views

Check if a file contains a certain pattern?

#!/usr/bin/expect -f ps ps -ef > test.txt Now if I want to check whether test.txt has certain keywords present, in it, how do we go about? say: 'apache' or 'fast' Can we use the if statement ...
0
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0answers
19 views

i am new to shell scripting..how to do a multiple backup's of a file in a sequence which is overwrting through shell scripting? [on hold]

Eg : Backup.txt in /tmp path backup1.txt, backup2.txt..etc even same file to write to sequential folder also is ok. eg : backup.txt to s1,s2,s3..etc
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0answers
38 views

Script for logging in to multiple servers and running some commands [on hold]

I have a list of host/server names in a text file. I want to log in to each host using SSH and run certain commands. I'm using password authentication. When ssh'ing to another server, how to handle ...
0
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0answers
5 views

db2 cursor in shell script

I want to select a row from table in db2 DB and check for each column value like while col1 = do else . I cannot direct the text to a file and use it. Can some one tell me how can i do this?
1
vote
1answer
935 views

Shell Script Help - Automatically assign users to group

Recently, I have just started to learn linux and I am currently trying to make a shell script that can automate the task of creating user accounts, assigning them passwords and then assigning them to ...
1
vote
1answer
29 views

Logrotation of a file

I want to rotate a file and place the rotated file inside a new directory called 'backup'. The rotation of the log is working fine where the rotated file is not getting moved inside the backup ...
1
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1answer
27 views

Comparing original & backup folder, then deleting non-existing files

I'm using Raspbian jessie (ubuntu). I made a .sh that makes a backup .img of everything (excluding mnt, tmp, run, dev, boot, etc.) and let this run once a week with crontab. It checks for modified ...
16
votes
4answers
18k views

find n most frequent words in a file

I want to find, say, 10 most common word in a text file. Firstly, solution should be optimized for keystrokes (in other words - my time). Secondly, for the performance. Here is what I have so far to ...
0
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3answers
31 views

Can I compare the parameter of a script to an array of variables and process it?

I want to manipulate the expanded value of a variable that has been selected from an array after user input. Here's what I mean: $ ./myscript.sh url2 #!/bin/bash array=(Sigil wp2epub csskit) ...
2
votes
2answers
47 views

Bash script to extract some information from Ebay HTML pages

I would like to filter the output of a search on ebay which I've exported to a text file. There are a number of results in the search but I've included just one example at the bottom of this post as ...
1
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1answer
35 views

How do I maintain sudo in a bash script?

If I run this script, how do I pass super user permissions to it? I wrote this just to setup new machines with the basics. I don't want to run every command with elevated permissions, but the commands ...
1
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3answers
33 views

Joining two parts together to make a single script

I'm trying to create a script to do the following: extract the magnet link from a lynx bookmark and then use it as part of a curl command. like this: curl ...
1
vote
2answers
137 views

View timestamp for CUPS print jobs

I'm looking for a way to view the timestamp of a job in CUPS. I've searched the man pages and can't seem to find it. The long term goal is to have a script that parses the time from the jobID and ...
1
vote
1answer
21 views

Issue with resize and stty on remote ssh script?

Scenario: Source host (Solaris 5.10, KSH), im trying to run the following script named sample.ksh on source #!/bin/ksh set -x Rediscover () { ssh user@hostB ./scripts/test.ksh } Rediscover exit 0 ...
0
votes
1answer
25 views

Give the command to remove duplicate lines in a .txt file and save the new file as new.txt file

I'm trying to do this but I cant create the file. I enter: sort myfile.txt uniq -u | tee newfile.txt and It wont create the file automatically. What am I missing here?
0
votes
1answer
29 views

separation of files on the basis of their name

I have a folder containing lots of files like 3 lac plus files. I have to separate them according to their names in three different folders. e.g. a few names are: 7msf_stem_0_mcannotate.pdb ...
0
votes
1answer
17 views

How to prevent garbled screen display while running scripts on remote hosts?

Current scenario: I am trying to run Unix shell script from a solaris 5.10 box, within the script one of the tasks is to ssh to another Linux host (ssh-key pair already setup) and run a set of ...
2
votes
2answers
45 views

How to ensure echo into a file has been flushed? [on hold]

I have two co-operating programs X and Y running on the same system. X some times uses Y to calculate some information. I use file based communication between the programs. When X wants Y to compute ...
2
votes
1answer
37 views

Adding folder name to .zip files inside it

I have file1.zip, file2.zip, etc. in folder called folder1. have similar folders folder2, folder3, etc. I need to add folder name to each .zip file inside these folders. So, files inside folder1 ...
1
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2answers
23 views

How do I create a rule for custom flag replacement with C shell?

I want to have the following behavior with grep: grep --java <rest of the command> Where --java would either dynamically convert to --include=*.java or internally be equivalent to it. Is ...
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votes
2answers
40 views

how to login a user using shell script [on hold]

In my computer i have two user(tiger,jenk) now i want to create a shell script for login user "jenk" from user "tiger" i m try this code [tiger@pagaltiger mytask]$ echo -e "IncorrectPassword\n" | ...
0
votes
2answers
25 views

Exec vs source error on ==

I run a strange error with the following code: #!/usr/bin/env bash a="a" b="a" if [ "$a" == "$b" ] then echo "Eq" fi chmod u+x script.sh Then executing the file will display Eq: $ ./script.sh ...
-2
votes
1answer
44 views

KSH for generating 'n' of rows for a table dynamically : Issue with if else statement

I need to generate billion of records in a text file for table loading purpose. My destination table defination is: CREATE TABLE txnrecords12( txnno int, txndate string, custno int, ...
0
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2answers
30 views

How do I search a directory of data files and print out how many times a certain word appears in each file?

This is what I currently have, however it prints the total number of times Author appears in all of the files: 128367 grep -roh 'Author' $1 | wc -w However how do I print out the word count for ...
0
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2answers
45 views

Need help in data arrangement

Could you please help me to sort this out, I have data which i would like get output in below format using shell/perl script. Data: Virtual Machine Test status Running. Assigned Server ...
1
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3answers
124 views

How do I run a command in a different tty?

Suppose there are two terminals, pts/0 and pts/1. In pts/0, I have fired a command: ls>/dev/pts/1 Then, we only get the output of the ls command in pts/1, but I want to run a command as well as ...
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2answers
63 views
1
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2answers
57 views

Stop bash script with any key

I'm writing a custom gnome-terminal profile which I want to stop with any key I choose. After pressing the key, my intention is to complete all my commands at that moment and start su. I've tried ...
1
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2answers
19 views

Trying to direct variable contents into command gives Ambigious Redirect

I'm trying to write a script which tests the http response from various Node servers I have running and which then emails me if any respond with a 502 error from Nginx (meaning one or more server has ...
12
votes
7answers
27k views

gpg asks for password even with --passphrase

I expect the following command to extract the gpg file without asking for password: gpg --passphrase 1234 file.gpg But it asks for the password. Why? This also have the same behavior: gpg ...
4
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4answers
263 views

files greater than a average size of directory?

how could I find all the files and directories with size larger than or equal to the average file size of the current directory?
0
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2answers
86 views

For loop cannot distinguish * syntax

set -x for f in ~/1/2/*/*_1.txt; do subdir="${f%/*}" pushd "$subdir" &>/dev/null file="${f##*/}" expTool INPUT1= "${f##*/}" INPUT2= "${f%_1.txt}_2.txt OUTPUT1= "${f%_1.txt}_3.txt" OUTPUT2= ...
0
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2answers
38 views

Why is crontab giving me a permission error message when I copy my backup?

I use a PuTTY session to copy my nightly backups to another location. I log in as the root user and change directories to /store/BackupLocation which holds backups from the last 100 days. I can then ...
2
votes
0answers
8 views

i3status script that change its text by itself

I am trying to add a block for rss the latest news in my status bar. The news is composed by a title and a description. The full text doesn't fit in the status bar, so I would like to make it read ...
1
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3answers
50 views

if always false with equal variables

I first get file size info with curl fileSize=$( curl http://linux.die.net/include/sys/ioctl.h --head | grep Content-Length | awk '{print $2}') echo $fileSize is 1825 then I download the file and ...
5
votes
5answers
360 views

BASH: how to pass a default argument if no arguments after the first were passed

I have a bash script with a case statement in it: case "$1" in bash) docker exec -it $(docker-compose ps -q web) /bin/bash ;; shell) docker exec -it $(docker-compose ...
0
votes
4answers
52 views

Find files using shell script

I have the below script which looks for the file in the current directory and evaluates to true if the file exists in the directory and evaluates to false if it does not #!/bin/bash printf "\n Please ...
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votes
0answers
16 views

Removing intermediate line breaks in muliple columns except the last new line character [closed]

Suppose If I have the data like this Col1|Col2|Col3 <br\> 123|abc\n<br\> xyz\n<br\> |abc\n<br\> def\n<br\> other rows<br\> <br\> In the above newline ...
1
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2answers
36 views

tr -d not work with carriage return

I want to get rid of \n from variable I found many answers for that which say "use tr -d" but tr -d not work for me echo "$test" | od -c 0000000 4 4 2 5 2 \n 0000006 then I use tr -d ...
6
votes
10answers
6k views

Copy only Specific text of a file to another

I have a file abc.txt the contents are <classpathentry kind="src" path="Sources"/> <classpathentry kind="con" path="WOFramework/ERExtensions"/> <classpathentry kind="con" ...
0
votes
0answers
26 views

Nginx Performance Monitoring: How to collect CPU, Memory and Disk Utilization data?

I'm relatively new to shell programming and I need to collect statistical data on nginx web server performance running on Linux VMs for further analysis. I have checked some tools and I find dstat ...
3
votes
1answer
117 views

sudo script - best practice?

I have a script in which some of the commands need to be run as sudo. I have seen it asserted that running sudo inside scripts is a bad idea, and that is is better to run the whole script as sudo (and ...
3
votes
4answers
413 views

Calculate date difference between Last modified date of a file and NOW using shell script

I am trying to calculate the time elapsed since the log file was last updated. I guess following commands will be used lastUpdate=$(date -r myLogFile.log) now=$(date) How can I subtract them and ...