Directing cat or grep command in variable

Shell Programming and Scripting
1

Hi,

I still have the problem with directing information from cat or grep to a variable.

For instance:

XMSG "$(date +%Y_%m_%d)_error_report.txt" "$(cat "$(date +%Y_%m_%d)_error_report.txt")" &

Works! The text received by cat is directed to my function.

If it is written like this, my variable var is empty

var=$(cat "$(date +%Y_%m_%d)_error_report.txt")

Same effect here:

var=$(grep "sdhdjhf" text.txt)

Can anybody please explain why the redirection does not work?

2

I would doubt on the multiple lines that cat file and grep something file would return :slight_smile:

Or non-existence of the file in case of cat and nothing found in case of grep

3

It oughta work. Seems to work here with this test scenario. Similar to previous response, two likely causes would be "file is empty" or "grep didn't find anything".

$cat temp.sh
echo "Line 1"  > lines.x
echo "Line 2" >> lines.x
x=`cat lines.x`
echo x = $x
y=$(cat lines.x)
echo y = $y
rm lines.x

$./temp.sh
x = Line 1 Line 2
y = Line 1 Line 2