BASH: How do I grep on a variable?

[Zurtex]

Hi, I've been running code which very frequently calls books.csv. e.g:

grep -i horror books.csv > temp

Except, I'm trying to move away from using temporary files or frequently calling books.csv to improve efficiency. So I tried something like

bookfile=$(cat books.csv)
grep -i horror $bookfile

Needless to say, it explodes (giving me about 40 lines of grep [data here] no such file or director), that's before I even try and save my grep output as a variable. Don't suppose anyone knows what path I need to be taking?

 

[mathmate]

bookfile=$(cat books.csv)

would expand to the contents of the file, which when executed with

grep -i horror $bookfile

will try to grep from files represented by the content of the csv file, in which case most probably the files don't exist.

If you want to use a parameter to represent the csv file, you could try:

bookfile=books.csv
grep -i horror $bookfile

or better still, if you want to grep from all .csv files (if you have many of them)

bookfiles=`ls *.csv`
grep -i horror $bookfiles

 

[Zurtex]

Oh that's cool, I'll try it out

I also got another solution:

bookfile=$(cat books.csv)
printf "%s\n" "$bookfile" | grep -i horror