script question
 

hello i want to search the startposition of some text but i have some problem with inserting the variable into the awk statement
the textlijn variable is filled with some text



textlijn=`head -n $file_length2 pics.txt | tail -n 1`


startpos=`expr awk 'BEGIN { print index("'$textlijn'", "changeModelePic") }' + 0 `
here is something fishy but what=====^^^^^^^^

thanx in advance
greeting bert

fishy? did you trying learning awk in the first place? you need to explicitly pass variables into a an awk script:

acid_kewpie i am just starting
can you give me more information on the code you provided or point me in the right way ( example)

thx for replying

The "-v" option to awk has to come before the actual awk program. It lets you associate a variable name with a given value inside the program. For example:

This tells awk that inside the program you give it, the variable "magic" will have the value "xyzzy".

Incidently, the reason your technique will not work is because the awk program itself is the part of the command line in single quotes. Single quotes on the command line turn off the meanings of most special characters like $. You cannot expand variables in single quotes.

You can also use ENVIRON inside an awk program:

This lets you access shell variables.

carl.waldbieser thx
thats realy clear explaind
the rest i will find out myself
thx Bert

btw here is the solution ( if someone need it in the future)
startpos=`awk -v magic="$textlijn" 'BEGIN { print index(magic, "changeModelePic") }'`

Re: script question
 

The answer is to learn how to do shell quoting properly, then you won't have to mess about with awk variables.
I haven't tested this, let me know if and how it doesn't work and I'll fix it.