Calling Awk in a shell script

Question

I have this command which executes correctly if run directly on the terminal.

awk \'/word/ {print NR}\' file.txt | head -n 1

The purpose i

Answer 1

you could also pass the value as a variable to awk:

awk -v varA=$1 '{if(match($0,varA)>0){print NR;}}' $2 | head -n 1

Seems more cumbersome than the above, but illustrates passing vars.

Answer 2

You should use AWK's variable passing feature:

awk -v patt="$1" '$0 ~ patt {print NR; exit}' "$2"

The exit makes the head -1 unnecessary.

Answer 3

In the shell, single-quotes prevent parameter-substitution; so if your script is invoked like this:

script.sh word

then you want to run this AWK program:

/word/ {print NR}

but you're actually running this one:

/$1/ {print NR}

and needless to say, AWK has no idea what $1 is supposed to be.

To fix this, change your single-quotes to double-quotes:

awk "/$1/ {print NR}" $2 | head -n 1

so that the shell will substitute word for $1.

Answer 4

Replace the single quotes with double quotes so that the $1 is evaluated by the shell:

awk "/$1/ {print NR}" $2 | head -n 1