Sponsored Content
Top Forums UNIX for Dummies Questions & Answers Difference between echo `ls -l` and echo "`ls -l`" ? Post 302912079 by Corona688 on Tuesday 5th of August 2014 03:44:08 PM
Old 08-05-2014
Well, for starters -- it's a pretty silly thing to do, either way. Why do echo "`command`" when you could just do command ?

But the difference is, quotes prevent a string from splitting on whitespace. Spaces, tabs and newlines all count as whitespace. If you do VAR="a b c", and use $VAR without putting it into quotes, the shell will split it in three.

So, quoted, it ends up being:

Code:
echo "one
incredibly
long
string
crammed
into
a
single
argument
containing
actual,
real
line
breaks
printed
literally"

And the unquoted way ends up being:

Code:
echo "one" "incredibly" "long" "string" "where" "each" "whitespace" "separated" "section" "becomes" "its" "own" "individual" "separate" "argument"

This is also one of many reasons why for LINE in `command` is a poor idea. It splits on whitespace, not lines.
This User Gave Thanks to Corona688 For This Post:
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

difference between echo and ""

hi guys wht is the difference between these two command in bash shell scripting $var1=world! $echo hello $var1 $echo "hello $var1" (8 Replies)
Discussion started by: srinivas2828
8 Replies

2. Shell Programming and Scripting

"sed" to check file size & echo " " to destination file

Hi, I've modified the syslogd source to include a thread that will keep track of a timer(or a timer thread). My intention is to check the file size of /var/log/messages in every one minute & if the size is more than 128KB, do a echo " " > /var/log/messages, so that the file size will be set... (7 Replies)
Discussion started by: jockey007
7 Replies

3. Shell Programming and Scripting

Difference between using "echo" builtin and /bin/echo

So in my shell i execute: { while true; do echo string; sleep 1; done } | read line This waits one second and returns. But { while true; do /bin/echo string; sleep 1; done } | read line continues to run, and doesn't stop until i kill it explicitly. I have tried this in bash as well as zsh,... (2 Replies)
Discussion started by: ulidtko
2 Replies

4. Shell Programming and Scripting

ksh script that echo " please insert your name " and store the output to a login.log file.

Hello All Nice to meet you all here in this forum, it's my 1rst time here i'm asking about a little issue that i face i added a ksh script that echo " please insert your name " and store the output to a login.log file. the script is working fine with normal telnet but Xstart is not working... (8 Replies)
Discussion started by: islam.said
8 Replies

5. Shell Programming and Scripting

With that logic this echoes "echo". Question about echo!

echo `echo ` doesn't echoes anything. And it's logic. But echo `echo `echo ` ` does echoes "echo". What's the logic of it? the `echo `echo ` inside of the whole (first) echo, echoes nothing, so the first echo have to echo nothing but echoes "echo" (too much echoing :P):o (2 Replies)
Discussion started by: hakermania
2 Replies

6. HP-UX

echo "selall;info;wait;infolog" | /usr/sbin/cstm problem

Hello, On a HP-UX 10.20 server I've executed something similar to this command: # echo 'selall;info;wait;infolog;view;done' | /usr/sbin/cstm But it returns sometype of "argument list too long" error. I suppose there is a way to fix it by using xargs but I can't figure it out. Any... (7 Replies)
Discussion started by: asanchez
7 Replies

7. Shell Programming and Scripting

"Simple" echo/reading variable question...

Hello, I have a simple(I think) question! Although simple, I have been unable to resolve it, so I hope someone can help! OK, here it is: 1)I have an awk script that prints something, such as: awk '{print $2}' a > x so x might hold the value of say '10' 2)Now, I just want to check to see if... (4 Replies)
Discussion started by: astropi
4 Replies

8. Shell Programming and Scripting

cmd || echo "something" - doesn't exit uppon error

Hi guys, I have a shell script where I have the following: for i in ad0 ad1 do gpart create -s gpt $i || echo "Cannot create GPT partition on "$i". Exiting ..." gpart add -s 128 -t freebsd-boot $i || echo "Cannot add freebsd-boot partition on "$i". Exiting ..." gpart add -s 4G -t... (2 Replies)
Discussion started by: da1
2 Replies

9. AIX

echo $varibla | mail -s "subject" "xxx@xxx.com" not ruuning as expected

Hi Folks, As per the subject, the following command is not working as expected. echo $variable | mail -s "subject" "xxx@xxx.com" Could anyone figure it out whats wrong with this. I am using AIX box. Regards, (2 Replies)
Discussion started by: gjarms
2 Replies

10. Shell Programming and Scripting

tcsh - understanding difference between "echo string" and "echo string > /dev/stdout"

I came across and unexpected behavior with redirections in tcsh. I know, csh is not best for redirections, but I'd like to understand what is happening here. I have following script (called out_to_streams.csh): #!/bin/tcsh -f echo Redirected to STDOUT > /dev/stdout echo Redirected to... (2 Replies)
Discussion started by: marcink
2 Replies
echo(1B)					     SunOS/BSD Compatibility Package Commands						  echo(1B)

NAME
echo - echo arguments to standard output SYNOPSIS
/usr/ucb/echo [-n] [argument] DESCRIPTION
echo writes its arguments, separated by BLANKs and terminated by a NEWLINE, to the standard output. echo is useful for producing diagnostics in command files and for sending known data into a pipe, and for displaying the contents of envi- ronment variables. For example, you can use echo to determine how many subdirectories below the root directory (/) is your current directory, as follows: o echo your current-working-directory's full pathname o pipe the output through tr to translate the path's embedded slash-characters into space-characters o pipe that output through wc -w for a count of the names in your path. example% /usr/bin/echo "echo $PWD | tr '/' ' ' | wc -w" See tr(1) and wc(1) for their functionality. The shells csh(1), ksh(1), and sh(1), each have an echo built-in command, which, by default, will have precedence, and will be invoked if the user calls echo without a full pathname. /usr/ucb/echo and csh's echo() have an -n option, but do not understand back-slashed escape characters. sh's echo(), ksh's echo(), and /usr/bin/echo, on the other hand, understand the black-slashed escape characters, and ksh's echo() also understands a as the audible bell character; however, these commands do not have an -n option. OPTIONS
-n Do not add the NEWLINE to the output. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWscpu | +-----------------------------+-----------------------------+ SEE ALSO
csh(1), echo(1), ksh(1), sh(1), tr(1), wc(1), attributes(5) NOTES
The -n option is a transition aid for BSD applications, and may not be supported in future releases. SunOS 5.10 3 Aug 1994 echo(1B)
All times are GMT -4. The time now is 09:59 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy