How to make extra stdin input in awk ?

khaan · 07-27-2007, 05:31 AM

Hi,

I am quite new at using awk and did not managed to get the following thing working:

I want to read and process some data (with some output redirection), and under given circumstances ask the user a question "and what to do with that ?", wait for an answer, do the appropriate action and resume the processing.

I found a sample program on the internet for reading standard input, but it generates a syntax error for me (line 2):

Code:

BEGIN { printf "Enter your name: "
	getline < "-"
	print  
}

Any help would be appreciated!

colucix · 07-27-2007, 09:29 AM

Which version of gawk do you have on your system? You can try to put parentheses at line 2, as in:

Code:

BEGIN { printf "Enter your name: "
	getline < ("-")
	print  
}

an explanation of this is in the "GAWK: Effective AWK Programming" guide (a must read for awk programmers) page 50.

khaan · 07-30-2007, 02:23 AM

Well, I first wanted to make my code run on the university server. It does not have gawk. It is a solaris with an old awk I could not version. I just have the last change of its man page going back to 2000.

Anyway, thank you for your help, I'll try the snipet at home as soon as I can.

colucix · 07-30-2007, 05:04 AM

Ok. However, take in mind that on most Solaris an extended version of awk called nawk is installed by default. I don't know exactly what are the differences and the portability issues between nawk and gawk, but on Solaris itself you have another chance. Good luck!