CODEWITHSUNDEEP
linuxawkpadding
user59036
user59036

Reputation: 203

How to pad dates with 0's in a data file?

I have a data file contain the following columns

Current Date     FirstName    LastName
 8/31/2014         AAA          BBB
 8/31/2014         CCC          DDD

What I want to do is extract the date in the CurrentDate column, convert it and put it into a new column with just the year and the month.

Like this:

CurrentMonth  CurrentDate     FirstName    LastName
 201408       8/31/2014         AAA          BBB
 201408       8/31/2014         CCC          DDD

I tried with awk command

awk -F $'\t' 'BEGIN {OFS=FS} { { split($1, val,"/") } print val[3] val[1],$0}' > outputFile

However the above command gives me 20148 rather than the 201408. 

CurrentMonth  CurrentDate     FirstName    LastName
 20148       8/31/2014         AAA          BBB
 20148       8/31/2014         CCC          DDD

How do I pad 0's into the date?

Upvotes: 1

Views: 72

Answers (2)

BMW
BMW

Reputation: 45243

with printf function in awk, use %02s

Here is the code

awk 'BEGIN{print "CurrentMonth  CurrentDate     FirstName    LastName"} 
     NR>1{split($1,a,"/"); printf "%s%02s\t\t%s\n",a[3],a[1],$0}' infile

CurrentMonth  CurrentDate     FirstName    LastName
201408       8/31/2014         AAA          BBB
201408       8/31/2014         CCC          DDD

Upvotes: 0

nneonneo
nneonneo

Reputation: 179422

Just use printf:

awk -F $'\t' 'BEGIN {OFS=FS} { { split($1, val,"/") } printf "%04d%02d\t%s\n", val[3], val[1],$0}'

printf in awk works much the same as printf in C; you can find the specifications for the format language on any C reference site (e.g. here). Briefly, in a format specification like %04d, % introduces a format operator, 0 means pad with zeros, 4 means the width to print out, and d means "print as a decimal number".

This awk script yields

201408  8/31/2014   AAA BBB
201408  8/31/2014   CCC DDD

Upvotes: 1

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