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

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votes
1answer
134 views

Pass string value to date in Unix

mm="27 Jun 2011" dd=$(date -d'27 Jun 2011' +%Y%m%d) echo $dd I want to use value of mm in second line. When i tried like below dd=$(date -d'$mm' +%Y%m%d) It is giving error.
-1
votes
2answers
270 views

shell script not running using crontab

This is my script mboxutil -l > n.txt sed 's/^.*user//' n.txt > n1.txt cat n1.txt | sed 's/^.//' > n2.txt sed 's/\/.*//' n2.txt > dss_list.txt rm -f n.txt rm -f n1.txt rm -f n2.txt sed -...
0
votes
1answer
69 views

How to extract particular fields from lines using shell commands?

File1: 27/07/2014 10.10.03 Breaker1 was closed by Mr. A.Basu Spectrum ui6dms 29/07/2014 04.50.53 Breaker1 was opened by Mr. D.Gupta Spectrum ui6dms and one note added 30/08/2014 03.20.01 EarthSwitch ...
0
votes
2answers
72 views

What is wrong with the code? [closed]

#!/bin/bash for ((i=1 ;i<=3;i++)) do echo "Enter gallon used(gal):" read gal echo "Enter Miles Obtained(mil):" read mil mileage=`echo $mil / $gal |bc` echo "scale=4; $mileage " | bc c=`echo $c + $...
0
votes
3answers
939 views

Bash: increment a variable in a while loop?

Bash newbie here! I have a bash script that for each file in a set, greps each line in the file for a string. Then it splits the line on commas, converts the 7th element to a float, and increments a ...
7
votes
3answers
798 views

Should I use a slash at the end of path variables in shell script or not? [closed]

Today when writing my shell script. A question suddenly comes to my mind. Since cd /target_dir and cd /target_dir/ both works. Should I add a slash at the end of my path variables in a shell script? ...
2
votes
3answers
404 views

Am I using a while loop wrong?

I found a list of projects to do, and one of them was something that generates amounts of change. I made this code: getamt() { echo "Enter amount of money." read amount echo "OK." } change() { amount=...
0
votes
2answers
210 views

validate record count in header

I am trying to write a script that should verify total detail records equal to the Record_count in header record, If not throw an error sample data 0001 HD SAP _AP Distribution 20150615 131723 ...
0
votes
1answer
26 views

Substituting the value with spaces for a variable in bash script - the correct way

I have a compilation script that can compile the program with and without the debug symbols. I want to ask via bash prompt ( read ) the user to choose whether he wants a debug version or not with ...
0
votes
1answer
272 views

Export mysql to remote server using one SSH session

I've come across a situation where I had to create a utilitary shell script that would be executed in many servers from different regions. The objective is to dump the local mysql database, copy it to ...
-2
votes
1answer
134 views

Comma and newline replaced with comma [duplicate]

How can I find the solution to replace ":" and newline with comma, and to remove "./" below is the sample format. ls -lRm ./www.toncemoy.com: www_ttoncemly_com, www_ttoncely_com, www_toncethly_com, ...
4
votes
4answers
2k views

How to Check the existence of multiple files in a directory and zip the same

I am facing an issue while checking the existence of files ending with the same string/pattern. The file names might be as follows abs_123.unl xyz_123.unl Currently my code is as below and working ...
1
vote
1answer
429 views

Syntax error at a semicolon in a shell script

The one liner command will be longer but this is the part that is throwing the error. for user in natural1 ; do cat <<EOT >> /home/$user/public_html/.htaccess <FilesMatch "wp-login....
1
vote
1answer
203 views

Silent installation of shell script using bash file [closed]

I have a setup file for Linux which is in shell script format. I'm trying to perform a silent installation by writing a bash script. When I directly access the script I'm unable to suppress the setup ...
3
votes
1answer
202 views

Approximating a floating point number with correct rounding off

How can I approximate a floating point number using shell-script (say, up to 4 digits after the decimal point)? I have two examples: A=1.2345678 and B=1.2345678E-05. So I would like to get A=1....
4
votes
7answers
6k views

Hiding Password in Shell Scripts

How can I hide a password in shell scripts? There are a number of scripts that are accessing database. If we open the script others also aware the username and password. So if anyone knows how to hide ...
0
votes
3answers
152 views

Creating a script that runs a simple command for all files in a directory

I need to use the text-based browser Lynx to dump 1000s of html files into text files, with the same filename. For any given filename.html the command is lynx filename.html --force-html --dump > ...
0
votes
1answer
122 views

Practical usage of “shift” shell builtin command?

I checked the /usr/bin/ssh-copy-id(part of openssh-client package at least under Debian) shell-script and it contains following if-statement: if [ "-i" = "$1" ]; then shift # check if we have 2 ...
0
votes
2answers
200 views

generate alphanumeric string from pattern

I want to generate host names for example from my patter like this: inc-[tnc][app|web][1-10] where it should output like below: inc-tapp1 inc-tapp2 . . inc-tapp10 inc-napp1 . . inc-capp10 inc-tweb1 . ...
1
vote
1answer
73 views

Can someone explain this tail + line to me?

I'm looking through some of the scripts that are on the servers and came across an 80MB shell script. Naturally curious I decided to look in there and came across this line: tail +4802 $0 | zcat - | (...
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votes
2answers
235 views

Enter a variable into a command in bash

My question should be simple for you guys. I am writing a simple script that runs a command but the file it would need is always different. Is there a way for it to ask: "Where is the file?" And ...
1
vote
3answers
93 views

How do I search for certain sections of a file and then extract only relevant information within that section?

I have a text file that is a server report which has about 1000 lines of information in it. I'm trying to write a script that can search the report for only certain pieces of information I'm looking ...
0
votes
1answer
39 views

Is it bad practice to put sections of main code in functions? [closed]

I didn't like the way the code that I had looked, so I compressed all of the main 'blocks' into functions. (This would also prevent the code from running if an error was present.) I don't know if this ...
10
votes
6answers
1k views

Is it possible to substitute “then” with brackets?

I first learned how to code in a C language, and using if ( code ) then code fi makes it really hard for me to read my code (don't ask why). Is there a substitute for then? Something like this: ...
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votes
2answers
50 views

Transform text records using only a “for” loop

I have an input file that is text, consisting of lines that look like: 352|C|PAID|7036|VOICE|01-FEB-12 I need to split each line into fields at the | (vertical bar) characters and output each field ...
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votes
2answers
47 views

OpenDNS automatic diagnostics

I've contacted OpenDNS support because advertising is not filtered on this site http://www.backpackerboard.co.nz/ They asked me to read these manual instructions OpenDNS Diagnostic Tool: What to ...
-1
votes
1answer
96 views

Comparing Oracle version in bash script

I'm trying to create a bash script to install an application that requires Oracle 11g client. How can I read in the version info within the bash script? sqlplus when run in Putty spits out the ...
0
votes
1answer
883 views

How to clear log files periodically?

I am new to shell scripting. I want to clear log files in a directory based on the dates. I have managed to gather this code: DIR1='/home/u01/app/oracle/servers/DIR1/logs' DIR2='home/u01/app/oracle/...
1
vote
2answers
165 views

How can I delete <93> <94> symbols in file? It is equivalent “ ”

I copied text from a PDF file in bash - vi and I get lines like this: echo <93>The Hypotenuse is $hypotenuse<94> I tried to change that in vi by: s/<93>/"/g But: E486: ...
4
votes
6answers
1k views

Loop in text files shell script

I have a list of files in one directory and a set of jpegs corresponding to each file in another directory. I need to loop over all files, and for each file name, determine the target directory. For ...
0
votes
1answer
65 views

A script to install OpenVPN & modify iptables?

I d like to automatize the install/config of OpenVPN on my client machines. Roughly, it should looks like : - apt-get openvpn - cp, edit, .... - modify iptables. Is it possible in one script ? or am ...
0
votes
1answer
52 views

How remove duplicates in same file and with if condition?

INPUT FILE: has all these values without header: customer ID, code, start_date, end_date 124343, DCW, 2015-07-06, 2016-08-03 235432, ABC, 2015-04-26, NULL 235432, ABC, ...
2
votes
4answers
153 views

How to see if there are any matching characters in a string?

I'm making a card hand generator, and I want it to note if a specific hand is generated, like a three of a kind or a full house. I was trying to figure out how to do it, and I thought of using grep on ...
0
votes
1answer
261 views

Creating service in SLES / SUSE 11 SP3

I have a python script that works very well executed from a (remote) console like this : sudo /srv/web-asset-server-master/python server.py The problem is, that it only lives as long as the console ...
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votes
3answers
297 views

find and replace strings with another string command line

I have a Ad-blocking hosts file with 0.0.0.0 IPs pointing to URLs. How to replace 0.0.0.0 with 127.0.0.1 command line without any visual text editor ? Manually doing this with nano , vi etc. is ...
0
votes
2answers
38 views

Where should startup scripts for a specific user be installed?

I have one script that will run when a specific user logs in. Where should this script and its assets be placed? I was planning to put it in /usr or /bin or /var, but I was wondering if there's a ...
0
votes
1answer
69 views

Terminal does not call 'then', reports a syntax error and command not found [closed]

I am a newbie for Linux. I have CentOS 7. I am running a very simple script from BASH. I executed the chmod command and then ran the script file from a terminal. I got an error saying "if command not ...
2
votes
3answers
115 views

Find strings in file1, count occurrences in file2

I have file1.txt with string values such as New Drug Application Drug Product Dosing instructions I need to count how often these strings occur in file2.txt with data such as Regulatory New Drug ...
1
vote
0answers
32 views

APCUPSD script can't close program

I want to use APCUPSD to stop a program (called ns_image_server) which runs in a terminal window when it detects that power has been lost, to give that program time to close before the computer shuts ...
1
vote
1answer
274 views

Passing multiple varibles to a script for SQL query

I have this script called info_code: #!/bin/ksh if [ $# -eq 0 ] ;then echo "Enter code : \c" read code echo "" else code=$1 fi code=`echo ${code} | tr '[a-z]' '[A-Z]'` echo "select * from ...
6
votes
5answers
142 views

How to find the next available file suffix (file_a.txt file_b.txt etc)

My system creates a new text file every time a certain event occurs. The files should be named file_a.txt file_b.txt file_c.txt etc. In a Bash shell script,how to find out what filename should be ...
0
votes
2answers
526 views

Using multiple awk commands within single line

Here is what am trying to do: My data is in sets of rows within same file (the variables vaa vbb are looping over it and am able to control it as required) What i need is to add an extra column before ...
1
vote
1answer
2k views

When to use #!/bin/ksh and #!/bin/sh? Need example [duplicate]

Also what are the main differences between these two. To execute a script is it necessary to write this at the beginning of script?
0
votes
3answers
2k views

In bash, how to call a variable and wrap quotes around its value as part of a command without causing the variable name to become a string literal?

So I want to add 10 seconds to a time. The command to do that came from here. To illustrate: STARTIME="$(date +"%T")" ENDTIME="$STARTIME today + 10 seconds" CALL="$(echo date -d $ENDTIME +'%H:%M:%S'...
1
vote
2answers
294 views

Using df and trying to awk a specific column

Among other problems with this script I am trying to make (this is the first unix/linux script I have ever made), I am trying to use df to get the % of disk space used and email it to the root. Our ...
3
votes
2answers
233 views

check for “errors” or “ORA-”

I want to check for "errors" or "ORA-" in Y.if there is an error then exit Y=`sqlplus -s user/passwd<< EOF exec test_Proc; exit; EOF` if [ echo $Y | awk '/ERROR/ || /ORA-/' ] ; then exit 1 fi ...
8
votes
2answers
517 views

Why does printf print more arguments than expected?

Why is this shell script printing inputs twice? I expected the script to ignore the inputs after 5. Script: #! /bin/bash echo "Enter 5 words : " read a b c d e printf "> %s %s %s %s %s <" $...
2
votes
3answers
290 views

Run a task in background and know the time of its termination

I need to run a unix shell script (my_script) in background and monitor it from web interface. I start the actual script from php like so: $command = 'my_script'; $pid= exec("nohup {$command} > {$...
1
vote
2answers
132 views

Is it possible to have bash variables persist between runs

I am trying to create an init script which queries losetup -f for a free loop device. Within the init script I have a start() which queries losetup -f for the free loop device to setup some stuff, and ...
1
vote
1answer
60 views

Obtaining unique lines with matching strings [duplicate]

I have a JSON like text file of records with duplicate ids that look like: {"ID":"93" , "ST":[42,77,51]} {"ID":"21" , "ST":[43,4]} {"ID":"94" , "ST":[65,11,4]} {"ID":"93" , "ST":[42,77,51,29,63]} {"...