Reading data from a file using awk

Question

I am new at shell scripting and I am trying to read data from a txt file which is in the following format.

A: 1, 2, 3, 4

B: 1,2; 3, 4

Here is my code:

awk -F':/,/;/ ' '{ echo $2 $3 $4 $5 $5 }' -f 'testread.txt'

I just need the numbers from the text file. Thanks.

Answer 1

The easiest way is probably just to make your field separator "anything that isn't numeric".

[ghoti@pc ~]$ cat input.txt 
A: 1, 2, 3, 4
B: 1,2; 3, 4
[ghoti@pc ~]$ awk -F'[^0-9]+' '{$1=$1; print;}' input.txt 
 1 2 3 4
 1 2 3 4
[ghoti@pc ~]$ 

The $1=$1 bit is just to force awk to rewrite $0 using the default output field separator.

Update:

More explicit output:

[ghoti@pc ~]$ awk -F'[^0-9]+' '{printf("1=%s 2=%s 3=%s 4=%s 5=%s\n", $1, $2, $3, $4, $5);}' input.txt 
1= 2=1 3=2 4=3 5=4
1= 2=1 3=2 4=3 5=4
[ghoti@pc ~]$ 

Answer 2

There are several issues with your command.

1. The argument for the -F option is a regular expression that specifies your desired delimiters. To select colons, commas, or semicolons as your delimiters, you need to use pipes, not slashes. Alternatively, you could use a bracket expression.

2. The AWK statement to output text is print, not echo.

3. The -f option is to specify a file containing an AWK program, not an input file. You don't need -f to specify an input file.

You want something more like this:

awk -F '[:,;]' '{ print $2 $3 $4 $5 }' testread.txt