Nested backticks in bash script not working

Question

I'm trying the following in a bash script:

COUNT=`cat "$NEWLIST" | wc -l | awk \' { print $1 } \` `

where NEWLIST is a string containing a list of files, one per line. But I get this error:

command substitution: line 74: unexpected EOF while looking for matching `''

Why is that failing? How do I use nested backticks?

(basically I'm trying to strip whitespace from the result of wc, but I'd also like to know how to use nested backticks anyways)

score 8 · Answer 1 · answered Mar 22 '11 at 01:04

8

That's one reason you should use $() instead of backticks.

Also, there's no need for cat or AWK:

COUNT=$(wc -l < "$NEWLIST")

answered Mar 22 '11 at 01:04

Dennis Williamson

Thanks. I was originally using awk because in my Mac OSX terminal, wc was producing leading whitespace. But it seems to be gone with the above expression. – mark Mar 22 '11 at 05:49

score 2 · Answer 2 · answered Mar 21 '11 at 23:24

2

That second "escaped backtick" should actually be a single quote, just like the first one. Also, be careful with the $1 there.

answered Mar 21 '11 at 23:24

score 2 · Accepted Answer · answered Mar 21 '11 at 23:24

2

You're mixing ' and `

COUNT=`cat "$NEWLIST" | wc -l | awk ' { print $1 } ' `

answered Mar 21 '11 at 23:24

Erik

3 Answers3