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3
votes
1answer
182 views

Linux: set command for local variables

I am trying to understand local/environment variables and export/set commands. $ set FILEM="razrax" $ echo $FILEM $ FILEN="test" $ echo $FILEN test Please explain why echo $FILEM returns empty ...
2
votes
1answer
36 views

When does one need to export a variable? [duplicate]

Eons ago, when I first started assigning variables in bash, it was something along the lines of: export EDITOR=nano export PS1=something ...and the likes. And the habit of exporting has kinda stuck ...
2
votes
2answers
44 views

Local variable as a part of global one

I have a question about something similar to this question, but I need to call global variable depending on local one. Say I want to pass either test, staging, or production as a variable to a ...
3
votes
2answers
77 views

using the variable “file” obtained from `for “file” in` and pass to another script fails [closed]

I am trying search for all .mkv files in my current folder, then using mediainfo I want to put the height from its meta data to a variable, but it seems it is failing. This snippet: ...
1
vote
2answers
79 views

check if a variable is in list

to check if a word is in a list of words or no I wrote this script: tr -s '[[:blank:]]' '\n' < t.txt | while IFS= read -r word; do if [[ "$word" =~ $(echo ^\($(paste -sd'|' ./champs.txt)\)$) ...
3
votes
3answers
166 views

Variable not expanding inside another variable bash

I am reading a csv file in bash script as follows: resource='/data/bscs/' while IFS='|'read seqid fname fpath do echo "FILENO: $seqid" echo "FILENAME: $fname" echo ...
1
vote
3answers
136 views

Shell expansion for arguments?

For example: mkdir ~/{1,2,3} Creates directories ~/1, ~/2, and ~/3. It equates to: mkdir ~/1 mkdir ~/2 mrdir ~/3 But, using the same syntax in the case of CMD < argument > : brew {install, ...
-2
votes
3answers
37 views

Syntax error when trying to cut part of a variable

If I write a simple echo $i, I have no problem: it shows me the variable. But if I try do something with it $($i|cut -d"." -f1-3) then I get an error messages : -bash: /...file.backup: Permission ...
2
votes
2answers
131 views

An error of variable type?

I've an error that I don't understand, it seems that that the problem is that my parameters into the shell are not of the same type as what they are in my SQL Database. For a better understanding: ...
1
vote
1answer
56 views

awk pattern with variable in a bash script

I have problem with command awk in bash I want to find pattern with variable, but it doesn't work. Can you tell me what's wrong with this line? awk -F" " "/$PWD/ {print $1,$3}" file.txt
0
votes
3answers
82 views

In BASH is there a way to read Variable names from a variable? [closed]

This is a bash question (hence posting here in Unix&Linux) I have a while loop that reads from a csv; It looks something like this: while read NAME PRETTY_NAME DESC; do echo $NAME done < ...
4
votes
2answers
96 views

Replace string in a file with another where both are saved in variables

I want to replace a string found in a file with another string, but both have a special character (in this example it is a . char) e.g 1.0 and 2.0. So this is the command currently used: sed -i ...
0
votes
0answers
15 views

What mail variable is needed to make sure I receive a copy as well when emailing an alias

The alias includes a list of addresses and includes mine as well what mail variable do I need to make sure I still receive a copy of the message as well?
1
vote
3answers
38 views

Variable related to variable

I want to get effect like bellow but I do not know how: $> A='/dir' $> B="$A/bin" $> echo $B /dir/bin $> A='/other' $> echo $B /other/bin any ideas?
4
votes
1answer
154 views

Can I refer to a global variable even if a locally scoped one exists with the same name?

If I have a variable x total=3 and then a function function A () { local -i total=0 } Is there any way I can update the 'global' total variable total from within function A ?
1
vote
2answers
79 views

How to format decimal number to display the preciding zero but not the trailing ones?

I have the following script on Ubuntu 14.04.1 LTS 64-bit bash command prompt: S=0.030 F=0.150 N=10 reso=20 DIFF=`echo "scale=3; $F - $S" | bc -l` df=`echo "scale=3; $DIFF / $N" | bc -l` is=`echo ...
1
vote
2answers
42 views

scripting- Ignoring a variable when undefined

HP-UX *** B.11.31 U ia64 **** unlimited-user license Hello, var1=abc var2=xyz touch $var1 $var2 $var3 if the one of the variable is not set the command fails with ksh: var3: parameter not set ...
1
vote
1answer
22 views

Comparing variables in arithmetic

Was wondering if someone can take the time to explain the following: I have a directory of files (PDF), which I place into an array. shopt -s nullglob # Set array ...
0
votes
2answers
50 views

How to use variables properly in this little script?

Here is a little script to retarget old-wrong symlinks that I want to make interactive. #!/bin/bash # retarget (broken) symbolink links interactively echo -n "Enter the source directory where ...
0
votes
1answer
28 views

Is there a valid way of exporting a variable across different shells?

For some reasons, Im using ksh and zsh in my scripts and returning to -bash, I need to use already set variable values in the spawned shells, writing it to some temp file and using that didn't look ...
0
votes
2answers
83 views

In a shell script, How to give a variable another value after one job is done?

I'm trying to make a script which will see if the directory exists and will zip all of its contents under it according to the name/path of the directory. The farthest I could go was - ...
1
vote
3answers
206 views

sed won't expand my BASH variable in script

I have this script, which will prompt for the relative or absolute path to the file and then swap whitespaces ' ' with '\ ' which works in Linux console. Substitution is done using the first sed ...
0
votes
1answer
178 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
86 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
120 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
65 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
128 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
47 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
57 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
54 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
74 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
46 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
465 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
115 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
29 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
197 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
247 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
67 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
901 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
107 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
81 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
869 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
62 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
51 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
268 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
137 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
94 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
72 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: $ ...
4
votes
8answers
5k 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. ...
7
votes
4answers
2k 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 ...