Shell Programming and Scripting

Hi..

I have data file.. and I could able to print using cat and awk

like this

Code:

cat filename
awk '{print $1 "\t" $2 "\t" $3}' filename

but I want to receive input from user like this

Code:

echo -n " how many columns you want to display : "
read abc

suppose if I give all, it should display all column, and suppose if I give 1,4,5,8,3

it should display only 1st, 4th,5th,8th,3rd column...

How can I do this...

I have one more problem,

I have one script...using for loop for that.. like this

Code:

for file in *.txt ; do
----------
---------
---------
done

if for loop executed successfully, I want to display

Code:

echo -e "Operation successful"

if not I want to display

Code:

echo -e "Check user input,operation unsuccessful"

please go through attached file

You seem to want tab separated output. Is the input tab separated, too? If not, what is the format of your input file?

Is it an error if one or more input lines don't contain a field your want to print?

This looks like you try to reinvent the "cut" program. But "cut" already exists, so it seems rather pointless. Have a look at the man page of cut.

I hope this helps.

bakunin

Actually I just tried to print using tab, my requirement is not tab separated.
I just want to receive input from user that, which column u wants to print..
if user gives input as all it has to display all column,
suppose if user gives input like this.. 1,2,3,5,7 it has to display these columns as given in a order....

---------- Post updated at 01:42 AM ---------- Previous update was at 01:41 AM ----------

Please Mr. Don Cragun have a look on attachment..

So, if the requirement is not tab separated output fields, what is the requirement for the output field separator?

I looked at your attachment. The last character of the last field on each line is a carriage return. So, any request to print field 8 followed by any other field will overwrite data sent to a video output device. This can easily be seen if you pipe the output through od -c. Will you remove these spurious carriage returns from your input files before feeding them into the script you're requesting, or does the script have to do that too?

Other than the fact that your fields have variable numbers of spaces instead of a single character as the field separator, you haven't said why cut won't do what you need. If you strip off leading spaces on each line and convert other occurrences of one or more spaces to a single space or tab, I don't see why cut won't do what you need.

Let me explain with my requirement

Assume this is my input file

Code:

      1.006   5.488193    27.9850    4.23149     1.7454     0.2259    34.0687      1.000 
      2.012   5.488272    27.9851    4.23844     1.7719     0.2071    34.0689      2.000 
      3.018   5.488225    27.9847    4.25130     1.7509     0.2158    34.0685      3.000 
      4.024   5.488208    27.9851    4.24312     1.7681     0.2201    34.0679      4.000 
      5.030   5.488127    27.9840    4.23286     1.7955     0.2403    34.0677      5.000 
      6.035   5.488064    27.9829    4.24553     1.8051     0.2633    34.0678      6.000

space separated...containing 8 columns,
suppose if user input is all then display all 8 column

if user input is 1,3,4,5,6
then cut or copy 1,3,4,5,6 column from file and display on monitor

Moderator's Comments:

edit by bakunin: Please view this code tag video for how to use code tags when posting code and data.

Brilliant application of cut!