curl command different from curl assigned to variable, in bash

Question

I'm getting a slightly different result when I run curl as a command than when I put its output in a variable and then read said variable.

1

x=`curl http://www.movies.com/rss-feeds/top-ten-box-office-rss 2> /dev/null`; echo $x

2

curl http://www.movies.com/rss-feeds/top-ten-box-office-rss 2> /dev/null

The differences between them are that when I do 2, I get everything and it is all formatted, and that, when I use option 1, besides being all one block, I miss all of the following (for each movie):

<pubDate>Tue, 04 Mar 2014 08:00:00 GMT</pubDate>
      <source url="http://www.movies.com">Movies.com Top 10 Box Office</source>
    </item>
    <item>
      <title><![CDATA[10. Ride Along - $2.0M]]></title>

I saw a similar question here (In ShellScript Assign Variable Based on Curl Output), but when I tried the proposed solution I get the same difference. Reading (and trying) flags doesn't help.

Apologies for the really beginner question.

Barmar · Accepted Answer · 2014-03-11 02:10:06Z

2

Use:

echo "$x"

to prevent word-splitting of $x.

In general, you should quote variables unless you know that they don't contain whitespace or wildcards, or you explicitly want those characters to be processed.

answered Mar 11, 2014 at 2:10

Barmar

789k57 gold badges555 silver badges669 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

John1024 · Accepted Answer · 2014-03-11 02:15:49Z

1

With echo $x (version 1), the contents of x are placed on the command line as arguments to echo and interpreted according to shell rules, and then echoed to the terminal. Use echo "$x" to prevent this.

With that one change, the two methods will produce output that is differs only by one character: the final newline. That character is removed by the shell when processing backticks. man bash documents this:

Bash performs the expansion by executing command and replacing the command substitution with the standard output of the command, with any trailing newlines deleted. Embedded newlines are not deleted, but they may be removed during word splitting.

edited Mar 11, 2014 at 2:15

answered Mar 11, 2014 at 2:10

John1024

115k15 gold badges152 silver badges183 bronze badges

Collectives™ on Stack Overflow

curl command different from curl assigned to variable, in bash

2 Answers 2

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related