11.1 Allowing Nondecimal Input Data

If you run gawk with the ‘--non-decimal-data’ option, you can have nondecimal constants in your input data:

$ echo 0123 123 0x123 |
> gawk --non-decimal-data '{ printf "%d, %d, %d\n",
>                                         $1, $2, $3 }'
-| 83, 123, 291

For this feature to work, write your program so that gawk treats your data as numeric:

$ echo 0123 123 0x123 | gawk '{ print $1, $2, $3 }'
-| 0123 123 0x123

The print statement treats its expressions as strings. Although the fields can act as numbers when necessary, they are still strings, so print does not try to treat them numerically. You may need to add zero to a field to force it to be treated as a number. For example:

$ echo 0123 123 0x123 | gawk --non-decimal-data '
> { print $1, $2, $3
>   print $1 + 0, $2 + 0, $3 + 0 }'
-| 0123 123 0x123
-| 83 123 291

Because it is common to have decimal data with leading zeros, and because using this facility could lead to surprising results, the default is to leave it disabled. If you want it, you must explicitly request it.

CAUTION: Use of this option is not recommended. It can break old programs very badly. Instead, use the strtonum() function to convert your data (see section Octal and Hexadecimal Numbers). This makes your programs easier to write and easier to read, and leads to less surprising results.