7
votes
3answers
2k views

What is the difference having double quotes or not in bash [duplicate]

I have some bash scripts, one which has the following content: #!/bin/bash source $(dirname ${BASH_SOURCE[0]})/script.sh while the other one has the following content: #!/bin/bash source "$(...
4
votes
1answer
358 views

Any problem assigning one variable to another in shell without using quotes? [duplicate]

This question is about assigning the entire contents of one variable to another variable. Variable is not being used (sent to echo, etc.) No parameter expansion is being done during the assignment. ...
1
vote
1answer
3k views

when to use double quotes with a variable in shell script? [duplicate]

I am in a confusion with what is meant by the double quotes referring to a variable. For example following two scripts gives the same output. What is really meant by the double quotes? Script1 ...
1
vote
1answer
884 views

What is the difference between $var and “$var”? [duplicate]

Possible Duplicate: $VAR vs ${VAR} and to quote or not to quote I assigned a variable var a value as follows: pradeep@pradeep-laptop:~$ var="Pradeep > is > a good > boy" Then ...
0
votes
2answers
151 views

What is the best practice between using ${var} or $var? [duplicate]

I know that ${var} and $var does the same thing. I also know that you can use brace for advanced options like ${var:=word} or ${var#pattern}. It's also explained here. But I see in some bash scripts ...
1
vote
1answer
140 views

what is diffrence between “$var” and “${var}” [duplicate]

i have seen in many script usage of "$var" and "${var}", so I just want to know diffrence between "$var" and "${var}"
0
votes
2answers
31 views

Passing variables to script [duplicate]

What is the difference between: ./script.sh "$VARIABLE" and ./script.sh ${VARIABLE} Is there any?
0
votes
0answers
18 views

Whats diference between ${X} and $X [duplicate]

I'm using a JetBrains IDE to write some bash-script and it is warning me about $X as variable usage, also the IDE suggest me to replace those declarations to ${X}. I'm little confusing about that, ...
52
votes
3answers
26k views

Quoting within $(command substitution) in Bash

In my Bash environment I use variables containing spaces, and I use these variables within command substitution. Unfortunately I cannot find the answer on SE. What is the correct way to quote my ...
37
votes
1answer
10k views

When is double-quoting necessary?

The old advice used to be to double-quote any expression involving a $VARIABLE, at least if one wanted it to be interpreted by the shell as one single item, otherwise, any spaces in the content of $...
10
votes
3answers
50k views

How can I concatenate a shell variable to other other parameters in my command lines?

How can I concatenate a shell variable to other other parameters in my command lines ? For example, #!/bin/sh WEBSITE="danydiop" /usr/bin/mysqldump --opt -u root --ppassword $WEBSITE > $WEBSITE....
15
votes
2answers
2k views

Are quotes needed for local variable assignment?

Can I safely omit quotes on the right side of a local assignment? function foo { local myvar=${bar} stuff() } I'm mainly interested in bash, but any info on corner cases in other shells are ...
8
votes
7answers
6k views

Splitting large directory tree into specified-size chunks?

I have a directory tree that I would like to back up to optical disks. Unfortunately, it exceeds the size of any one disk (it's about 60GB). I am looking for a script that would split this tree into ...
5
votes
3answers
5k views

Why the double quotes and backquotes in a shell script?

I'm looking at this script mysql backup script and I don't understand what is the reason for using both backticks and double quotes around command names? 379 WHICH="`which which`" 380 AWK="`${WHICH} ...
1
vote
2answers
10k views

Creating an empty file having a variable name in a script

I need to create an empty file using a shell script. The filename will be determined by examining all the files in a directory matching a pattern, say TEST.*, and appending _END to it so that the new ...
5
votes
3answers
2k views

Quote a variable in shell script “if” statement

e.g. if [ "$FOO" = "true" ]; then vs if [ $FOO = "true" ]; then What is the different? Seems both of two statements also works.
1
vote
2answers
2k views

$(tail) into variable removing \n

I am doing the following: x="Hello to the world of tomorrow\n <pre>"; x="${x}$(tail -n 50 log/logfile.log)" x="${x}</pre>"; echo -e $x | ./perlscript The Perl script: #!perl # ...
5
votes
2answers
393 views

Bash, curious about echo $variable

I was hacking at a small script earlier and noticed something I can't explain. Running this command (time wget --spider http://www.google.co.uk/) 2>&1 | egrep 'real|response' gives me ...
-1
votes
3answers
4k views

printf white space character in bash script

How can the white space character be escaped in printf for the purpose of this script that currently runs in a Cygwin client? The line containing the whitespace (which by itself works from the command ...
0
votes
1answer
4k views

How to move file from one folder to another in shell script by changing the permission

I want to move a file from one folder to another folder. When the file's format is with space in between (file _name.dat) and when I am using the command mv file _name.dat /tmp then the file is not ...
3
votes
1answer
3k views

Printf formatting with variable format - what does this var reference?

I am experimenting with printf formatting in bash and I ran across this piece of code: #/bin/bash divider=============================== divider=$divider$divider header="\n %-15s %8s %10s %11s\n" ...
1
vote
1answer
185 views

bash script disapearing variable

I have created a small script to move video files from a helmet mounted camera to my mythbuntu machine and there is a variable that for some reason will just not be passed onto the script. The ...
4
votes
2answers
889 views

Shell Script to isolate files scattered in different folders

I need to write a shell script that traverses a given directory structure in multiple levels, recognizes the video files scattered in the folders and copies all of them to another single folder. The ...
1
vote
1answer
2k views

Outputting last modification date to another file?

I'm trying to read the number of lines in a file, and the last modification date of that file (e.g. if it was last modified Jan 18, 2013, it should output 2013-01-18), then append the data to the ...
1
vote
1answer
844 views

Read a variable with “read” and preserve backslashes entered by the user

I'm using read to read a path from a user like so: read -p "Input the file name: " FilePath The user now enters this string: \Supernova\projects\ui\nebula What can I do to replace \ with /. The ...
1
vote
1answer
1k views

Concatenate multiple strings with spaces in them?

I am trying to do the following in ksh shell: JMX_ROOT=/bfs-build/build-info/mep_mainline-Linux.latest/core/mainline/automation SMOKE_JMX_LOCATION="$JMX_ROOT/\"Smoke Set\"/*.txt $JMX_ROOT/\"Smoke ...
1
vote
1answer
594 views

Shell variables not working?

I'm trying to store the date in a variable ($DATE) so I can use it later, but it doesn't seem to work. See anything wrong? DATE=$(date +"%Y-%m-%d %R") sudo mysqldump -u root -pnotgivingyoumypassword -...
3
votes
2answers
322 views

open a file using CDPATH and symlink

To quickly move around, I added a path to CDPATH that contains symlinks to different locations. I did this by adding the following line to .bashrc: export CDPATH=~/symlinks When working with ...
2
votes
2answers
345 views

What is PATH on a Mac OS?

What is the PATH in a Mac OS? I have used it to install global command-line tools, but the only documentation I have found are tutorials for doing just that, with no real explanation of what is ...
3
votes
2answers
293 views

Bind locally installed library

I have no root-acces on a machine and i'm trying to install a library called GiNaC locally in my home folder. I use this tutorial http://www.ginac.de/tutorial/Configuration.html#Configuration. At the ...

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