The tag has no wiki summary.

learn more… | top users | synonyms

0
votes
1answer
20 views

How to assign the cat output of a bash script to a variable in another script

I have a bash script that produces a cat output when it takes an argument. I also have another bash script that executes the first bash script with an an argument that I want to produce cat outputs ...
2
votes
3answers
72 views

Using find with 2 sets of variables

I want to be able to run a find command in my bash script that will find files based on two seperate variables. I've gotten this far but I'm not sure how to get the final result workingfind . -user ...
2
votes
2answers
57 views

Using the output of `grep` as variable in second command

I currently have 2 bash command line strings I use to gather data needed for a certain task. I was trying to simplify and have only one command used to gather the data without using a script. First I ...
1
vote
1answer
27 views

Read from character delimted file and assign into variables | for email

I am using ksh. I need to read the data from file, into the variables and then further use them for sending emails. File can be delimited by any less used characters (like | ^ etc.) or group of ...
3
votes
2answers
108 views

Assign specific line from a variable to another variable

I would like to take a specific line from a variable to another variable. I tried this but it doesn't work: c="1.apple 2.banna 3.peach" read "Please choose fruit [1-3]:" t a=$c | awk "NR==$t" echo ...
0
votes
1answer
27 views

Insert variable value as element in array

If I have a variable that has a value stored and I want to place that value into an array using the name of the variable, how would I do this? e.g.: variable="Hello there" array[0]=$variable does ...
1
vote
3answers
45 views

Use a variable as part of name of an array name?

I essentially have a for loop where the variable i that I am iterating with will take on each letter of the alphabet, for example. I want to use each value of i to create an array called "$i"array ...
1
vote
1answer
40 views

Why doesn't my function work with spaces? (cd, dirname) [duplicate]

I have had this function I use it very often and it works fine. Here it is: cdx () { cd `dirname $1` ; } However, this does not work with spaces. When I use it like this for example cdx ...
1
vote
1answer
28 views

SQLPLUS value in variable- not working from crontab

I am trying to store sqlplus value to a variable in Linux. Script is working fine when triggered manually. But value in variable is not stored when the script is called from crontab. Code: ...
2
votes
1answer
30 views

Export path with space in directory name [duplicate]

I have a path "/third/party/city of las vegas" when cd the path I use "/third/party/city of las vegas". In .profile file I have exported the path to a variable as follows export ...
2
votes
2answers
68 views

How to use variables inside single quotes

I have an application which takes as an input attributes in double quotes embedded in single quotes. Take for example this right command: command -p 'cluster="cl1"' In order to automate it, I ...
3
votes
2answers
68 views

How to use tee to capture STDOUT from a code block to a filename defined within the block?

I want to send STDOUT for a script block to a file which name is defined by a variable within the block. However, when I use tee, it seems the variable outside the block doesn't exist anymore. Without ...
-1
votes
1answer
28 views

what directory is used to execute “expr” command,what holds it process-id and log record [closed]

What directory execute the expr command. What directory holds the the PID of the command. What directory hold the log file of this command.and how to read all these??
4
votes
3answers
145 views

Using | pipe character from a $variable makes it treat as just another argument in bash; how to escape it?

I have a bash script like this export pipedargument="| sort -n" ls $pipedargument But it gives the error ls: |: No such file or directory ls: sort: No such file or directory It seems to be ...
4
votes
2answers
164 views

Running commands stored in shell variables

The following works in my shell (zsh): > FOO='ls' > $FOO file1 file2 but the following doesn't: > FOO='emacs -nw' > $FOO zsh: command not found: emacs -nw even though invoking emacs ...
2
votes
1answer
64 views

Why string comparision results always false

I am trying to do a one time check about apache's mod-status page for updates like this(this is just a test script): firstcontent=$(lynx -dump http://some-server/server-status-page) echo ...
2
votes
4answers
201 views

Extracting the second word from a string variable

I have a string "rtcpOnNbActive true" stored in a variable x. I want to extract "true" as substring and store in a variable. How can I do this?
2
votes
3answers
77 views

How can I print only variables defined inside my shell script?

Lets supose some bash shell script like: #!/bin/bash a=3 b=7 set -o posix set In this case, the execution of the set variable or some other of the commands to print environment variables ...
0
votes
2answers
47 views

How can I expand all variables at the command line in Zsh?

In an earlier question, specific to bash, I asked How can I expand a relative path at the command line, with tab completion? I liked @Mikel's answer that mentioned using Ctrl+Alt+e to expand all ...
13
votes
2answers
858 views

How can variables use “~” for cd'ing?

How can I use a variable - $BASE in my cd. I tried the following but I get an error $ cd ~/z/repo_1_ruby_193/ 23:23:57 durrantm Castle2012 /home/durrantm/z/repo_1_ruby_193 $ BASE="~/z" 23:24:03 ...
1
vote
1answer
58 views

How do I define alias with variables which can be changed at runtime?

This is probably a very easy to answer question, but I could not find any questions already asking this due to different wording when writing titles. Running help alias on my bash prompt returns only ...
2
votes
1answer
34 views

Append same timestamp to multiple filenames

I have several files that I ftp each hour. The receiving system needs to have some sort of identifier that they came from the same batch, so I would like to append a timestamp to the filename. That ...
2
votes
1answer
127 views

Error passing variable from bash to php

I have the following files: vars.txt C=1234567890 Ascript.php #!/usr/bin/php <?php var $C="$argv[1]"; echo "\n $C \n"; $con = mysql_connect('localhost','root','123') or die ("No connected"); ...
1
vote
1answer
72 views

Get two values from command output in a bash script

I have a bashscript, which executes a command and calculates a pair of values, which output can look like this. a,b (10.0000000000, 10.0000000000) -> volt (2088133.7088034691, -222653.3238934391) ...
1
vote
0answers
68 views

passing variable through cat EOF command with for loop

How do I get the script run with the sbatch command to run with the 23 individual run_prep_chem_$dd.sh (i.e. run_prep_chem_08.sh...run_prep_chem_30.sh)? I am thinking since its in this for loop that ...
3
votes
3answers
71 views

How can I base the file name off of an already existing variable?

I'm using this to delete lines that don't match a pattern: $ egrep "pattern1|pattern2|pattern3|pattern4|pattern5" But now I need to do it automatically, so I'm setting a variable like this: $ ...
3
votes
8answers
1k views

How to assign a string value to a variable over multiple lines while indented?

The issue: I need to assign a variable a value that is decently long. All the lines of my script must be under a certain number of columns. So, I am trying to assign it using more than one line. ...
6
votes
4answers
730 views

shortest way to replace characters in a variable

There are many ways to replace characters in a variable. The shortest way I found out is tr so far: OUTPUT=a\'b\"c\`d_123and_a_lot_more OUTPUT=$(echo "$OUTPUT"|tr -d "'\`\"") echo $OUTPUT Is ...
6
votes
5answers
335 views

Number of characters in a shell command's output

I am writing a script which needs to calculate the number of characters in a command's output in a single step. For example, using the command readlink -f /etc/fstab should return 10 because the ...
0
votes
2answers
98 views

Bash Mysql Command Substitution Login Failure

Bash and MySQL versions: GNU bash, version 4.2.25(1)-release (x86_64-pc-linux-gnu) mysql Ver 14.14 Distrib 5.5.37, for debian-linux-gnu (x86_64) using readline 6.2 I have a bash script that tries ...
4
votes
1answer
79 views

Length of argument inside a function of an sh script

I have a FreeBSD 9.3 RELEASE server and I am trying to write a shell script using sh. I am trying to get the length of a variable that is passed to a function in a shell script, like so: #!/bin/sh ...
3
votes
2answers
675 views

Assign Subshell background process pid to variable

I am currently starting a background process within a subshell and was wondering how can I assign its pid number to a variable outside the subshell scope? I have tried many different ways but MYPID ...
4
votes
1answer
392 views

Bash: Variable assignment doesn't seem to 'stick' [duplicate]

I am having a hard time tracking down the reason my 'boolean' flag variable won't stay false when a test fails inside a while loop. The script involves a few loops but essentially it is intended to ...
4
votes
2answers
104 views

Shell script error handling while assigning STDOUT to variable

I am trying to implement error handling in my shell script as described in the 2nd answer in Best practice to use $? in bash? My script looks like this: #!/bin/bash try() { "$@" code=$? ...
2
votes
1answer
616 views

Storing whitespace in a shell script variable [duplicate]

I need to store specific number of spaces in a variable. I have tried this: i=0 result="" space() { n=$1 i=0 while [[ "$i" != $n ]] do result="$result " ((i+=1)) ...
3
votes
5answers
1k views

How to use a shell variable inside sed's s command? [duplicate]

we know that we can get the value of a variable using $ sign: x=3 echo $x 3 Is there other ways that we can use to get the value without using $ sign. I'm asking this because $ sign is a special ...
6
votes
3answers
346 views

Attempted assignment to non-variable?

We can use arithmetic operations inside shell script function: function mess { if (( "$1" > 0 )) ; then total=$1 else total=100 fi tail -$total /var/adm/messages | more } I ...
3
votes
2answers
165 views

Command substitution declaration syntax in bash - which of these two is better practice? [duplicate]

This is part of a bash find loop, and I wondered which is more correct syntax and why? filename="$(echo "$i" | cut -c5-)"; filename=`echo "$i" | cut -c5-`; Both function for the purpose of getting ...
1
vote
1answer
163 views

How can I use global variable arrays in aliases or functions

I am attempting to simplify repetitive work procedures. In doing so, I am trying to write a .bashrc script which will set global path variables that aliases can refer to. Disclaimer: I'm new to linux ...
5
votes
1answer
551 views

ifconfig -a in a shell script

I am writing a shell script to start my network in my virtual machine on boot, since it does not do this right away for some reason with a snapshot of a virtual machine. Since the eth device starts ...
2
votes
1answer
77 views

Could “>” be included in a bash Variable?

Current approach: sudo awk 'BEGIN{printf "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n<hello>\n\t<world>\n";} {print "\t\t",$0}END{printf "\t </world>\n</hello>\n"}' ...
1
vote
1answer
1k views

command not found in shell script

Please tell me why I couldn't print variable value. # chmod 777 chkscript.sh # ./chkscript.sh chkscript.sh file content variable = "This is variable" echo "$variable" echo "Hello World " ...
1
vote
1answer
38 views

Insert variable and keep the variable

I'm on VMWare which, no matter what anyone says, responds to most unix commands. Some things are unique though, for example the fact that almost no files are persistent through reboot. Due to this ...
2
votes
1answer
158 views

What is the difference between filename=${1:-/etc/hosts} and filename=/etc/hosts? [duplicate]

What is the difference between filename=${1:-/etc/hosts} and filename=/etc/hosts? For example: filename=/etc/hosts if [ -r "$filename" ] && [ -s "$filename" ]; then md5sum $filename ...
2
votes
3answers
51 views

Reuse similar flags for multiple commands

Let's say I want to execute several commands with similar flags such as: du -sh / --exclude=/dir1 --exclude=/dir2 --exclude=/dir3/dir4 tar cvf archive / --exclude=dir1 --exclude=dir2 ...
1
vote
2answers
546 views

list files and store it in variables

im new with shell programming. my goal is to give the user a selection which file should be run. i catch all available scripts in one var with: var=$(find script*) so far so good.. this is the ...
0
votes
1answer
315 views

Bash Script : Passing a variable to a bash script that contains quotes, single quotes. etc [closed]

lets assume this is the string: 'a',"b" it contains both single and double quotes. how would you pass this to a bash script as a single string ? this is the bash script: #!/bin/bash echo $1 ...
1
vote
0answers
25 views

How to combine Bash's read with HERE-document when shopt -os errexit is in place? [duplicate]

I am trying to make use of the solution presented in one of the answers of http://stackoverflow.com/questions/1167746/how-to-assign-a-heredoc-value-to-a-variable-in-bash In Bash version ...
4
votes
1answer
916 views

Variable scope in while-read-loop on Solaris

Could someone please explain to me why my while loop seems to have an internal scope? I've seen multiple explanations online but they all have to do with pipes. My code has none. The code: ...
5
votes
1answer
87 views

What else can break if I remove export from a variable?

My problem is that when I started coding my script I encountered several variable scope issues which resulted in the bad habit of exporting almost all my variables. Now that my code has got quite ...