Print rest of the fields in awk

Question

Suppose we have this data file.

john 32 maketing executive
jack 41 chief technical officer
jim  27 developer
dela 33 assistant risk management officer
         


        

Answer 1

Reliably with GNU awk for gensub() when using the default FS:

$ gawk -v delNr=2 '{$0=gensub("^([[:space:]]*([^[:space:]]+[[:space:]]+){"delNr-1"})[^[:space:]]+[[:space:]]*","\\1","")}1' file
john maketing executive
jack chief technical officer
jim  developer
dela assistant risk management officer

With other awks, you need to use match() and substr() instead of gensub(). Note that the variable delNr above tells awk which field you want to delete:

$ gawk -v delNr=3 '{$0=gensub("^([[:space:]]*([^[:space:]]+[[:space:]]+){"delNr-1"})[^[:space:]]+[[:space:]]*","\\1","")}1' file
john 32 executive
jack 41 technical officer
jim  27
dela 33 risk management officer

Do not do this:

awk '{sub($2 OFS, "")}1'

as the same text that's in $2 might be at the end of $1, and/or $2 might contain RE metacharacters so there's a very good chance that you'll remove the wrong string that way.

Do not do this:

awk '{$2=""}1' file

as it adds an FS and will compress all other contiguous white space between fields into a single blank char each.

Do not do this:

awk '{$2="";sub("  "," ")}1' file

as it hasthe space-compression issue mentioned above and relies on a hard-coded FS of a single blank (the default, though, so maybe not so bad) but more importantly if there were spaces before $1 it would remove one of those instead of the space it's adding between $1 and $2.

One last thing worth mentioning is that in recent versions of gawk there is a new function named patsplit() which works like split() BUT in addition to creating an array of the fields, it also creates an array of the spaces between the fields. What that means is that you can manipulate fields and the spaces between then within the arrays so you don't have to worry about awk recompiling the record using OFS if you manipulate a field. Then you just have to print the fields you want from the arrays. See patsplit() in http://www.gnu.org/software/gawk/manual/gawk.html#String-Functions for more info.