BASH: can grep on command line, but not in script

Question

Did this million times already, but this time it's not working I try to grep "$TITLE" from a file. on command line it's working, "$TITLE" variable is not empty, but when i run the script it finds nothing

*title contains more than one word

echo "$TITLE"
cat PAGE.$TEMP.2 | grep "$TITLE"

what i've tried:

echo "cat PAGE.$TEMP.2 | grep $TITLE"

to see if title is not empty and file name is actually there

Solution 1

Are you sure that $TITLE does not have leading or trailing whitespace which is not in the file? Your fix with the string would strip out whitespace before execution, so it would not see it.

For example, with a file containing 'Line one':

/home/user1> TITLE=' one '
/home/user1> grep "$TITLE" text.txt
/home/user1> cat text.txt | grep $TITLE
Line one

Try echo "<$TITLE>", or echo "$TITLE"|od -xc which sould enable you to spot errant chars.

Solution 2

This command

echo "cat PAGE.$TEMP.2 | grep $TITLE"

echoes a string that starts with 'cat'. It does not run a command. You would want

echo "$( cat PAGE.$TEMP.2 | grep $TITLE )"

although that is identical in functionality to the simpler

cat PAGE.$TEMP.2 | grep $TITLE

And as pointed out by others, there is no need to pipe a single file using cat; grep can read from files just fine:

grep "$TITLE" "PAGE.$TEMP.2"

(Your default behavior should be to quote parameter expansions, unless you can show it is incorrect to do so.)

Comments

[Šimon Tóth]

Have you actually tried to grep the file with the value? Maybe the title really isn't in the file.

[cdarke]

But the first time you had quotes around the "$TITLE", the second time you don't.

[Crazy_Bash]

WORKED! thanks man! od -xc helped me, great tool. i added tr -d '\r\n\' and that fixed the problem.