Grep error due to expanding variables with spaces

Question

I have a file called "physics 1b.sh". In bash, if I try

x="physics 1b"
grep "string" "$x".sh

grep complains:

grep:  physics 1b: No such file or directory.

However, when I do

grep "string" physics\ 1b.sh

It works fine. So I guess the problem is something to do with the variable not being expanded to include the backslash that grep needs to recognize the space. How do I get this to work?

Using bash 3.2, mac os 10.6.

Edit:
Never mind, the problem was that x was set to " physics 1b", but when I did echo $x to check the contents, bash chopped off the spaces in the front so I couldn't tell that it was different. The first way above actually works.

Note that there is a space in front of '` physics 1b`' in the error from grep; are you sure it didn't mention .sh on the end of the file name? — Jonathan Leffler, Mar 30 '10 at 07:12

score 9 · Accepted Answer · answered Mar 30 '10 at 06:53

9

Put the entire argument in double-quotes:

grep "string" "$x.sh"

answered Mar 30 '10 at 06:53

Marcelo Cantos

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That shouldn't be necessary, even without the edit to the question, though it is often the best way to deal with the issue. – Jonathan Leffler Mar 30 '10 at 07:09

score 2 · Answer 2 · answered Mar 30 '10 at 06:54

2

use this in your script.

grep "string" "${x}.sh"

answered Mar 30 '10 at 06:54

Vijay

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score 0 · Answer 3 · answered Mar 30 '10 at 06:57

0

another way

grep "string" "${x}.sh"

answered Mar 30 '10 at 06:57

ghostdog74

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Grep error due to expanding variables with spaces

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