Append to a variable in awk

Fatipati

3/3/24, 9:34 PM

When using bash I can append to a variable with +=. I want to do something similar in awk. What can I use ?

  rl="?(+)*([$dgt])?([.,])+([$dgt])"
  rl+="?([eE]?([-+])+([$dgt]))"

156

2 + 0

awk

Score:1

Ubuntu

steeldriver

3/3/24, 9:53 PM

String variables in awk are concatenated simply by writing them side-by-side. So:

rl="?(+)*([$dgt])?([.,])+([$dgt])"
rl = rl "?([eE]?([-+])+([$dgt]))"

(the intervening whitespace is optional).

See String Concatenation.

BTW if you are trying to pass a shell variable $dgt into your awk program, don't do it like that - use something like -v dgt="$dgt" on the command line and then rl = sprintf("?(+)*([%s])?([.,])+([%s])", dgt, dgt) to write it into the string. You could even consider using sprintf to do the concatenation:

rl = sprintf("?(+)*([%s])?([.,])+([%s])", dgt, dgt)
rl = sprintf("%s?([eE]?([-+])+([%s]))", rl, dgt)

+ 0

Score:0

Ubuntu

Gilles Quenot

3/3/24, 9:38 PM

Dunno what means your regex attempts, anyway try this:

$ awk '{var="foo"$1;print var}' <<< bar
foobar

+ 0

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