new column to a tab delimited file, with as predefined value

Question

How can I add a new column to a tab delimited file, at the end of the file, containing the same values for each row.

For example:

infile.txt

Name    Age Address Sex
X   12  adrs1   M
Y   15  adrs2   F
Z   10  adrs3   M

I want to add another coloumn 'School' containing same values'st.xaviers ' for each row

outfile.txt

Name    Age Address Sex School
X   12  adrs1   M   st.xaviers  
Y   15  adrs2   F   st.xaviers
Z   10  adrs3   M   st.xaviers

I have tried awk '{print $0, "School"} to add the column. How can I add the 'st.xaviers' to each row in column "School" ?

Now, if this is part of shell script, and I have a predefined variable School=st.xaviers.

How Can I add $School values to the Column 'School' in outfile.txt

Answer 1

I swear the very same question was asked and answered a couple of weeks ago... but I can't find it.

The recipe is:

• check if the first column is "Name", and print the line a TAB and "School" when it is; done, skip to the next line
• all the othern, non-empty lines ($1 exists) must be printed with a following TAB and "st.xaviers"

Such as:

awk -vschool="$School" '$1=="Name" { print $0 "\tSchool"; next}; $1 {print $0 "\t" school}'

or

export School
awk '$1=="Name" { print $0 "\tSchool"; next}; $1 {print $0 "\t" ENVIRON["School"]}'

The former one defines an awk variable using -v, the latter peeks into its environment after export allows it to see School.

Answer 2

If you allow Perl as a superset of awk:

perl -p -i -e 's/Sex$/Sex\tSchool/ or s/$/\tst.xaviers/'

I imagine a similar construction is possible in awk (or sed) too.