Print smallest integer from file using awk custom function?

MR ZenWiz mrzenwiz at gmail.com
Sat Jan 9 17:09:51 UTC 2016


 On Fri, Jan 8, 2016 at 6:23 AM, asad <a.alii85 at gmail.com> wrote:
> `awk` function looks like this in a file name `fun.awk`:
>
>     {
>
>     print f()
>     }
>     function f()
>
>     {
>
>
>     if(NR==1){s=$0}
>
>
>     if($0<p)
>
>     {s=$0}
>
>     {p=$0}
>
>      { return s}
>
>     }
>
> The contents of `awk.write`:
>
>     1
>     23
>     32
>
> The `awk` command is:
>
>     awk -f fun.awk awk.write
>
>
> but it print x3 times. why?
>
It is a bit tricky to tell what this is supposed to do since your
formatting has no black delineations.

However, your function will parse this way:

if (NR == 1) { s = $0; }   # if there are no other records, save $0 in s

if ($0 < p) { s = $0; }   # if the new value $0 is less than the
uninitialzied variable p, save $0 in s
{ p = $0; }   # save $0 in p (why?)
{ return s; }  # return the current value of the s

1. [Style/clarity] You don't need black delimiters "{" and "}" around
single line statements, though you can use them.  They make reading
for actual blocks, like function bodies, tricky. A semicolon will do
(and should be used for clarity to the reader).

2. [Style/clarity] You don't need to return global variables from
subroutines, you can just use them.

3. [Function] You print the return value of function t for every input
line.  If you just want a single output, put the print statement in an
END block.

HTH
MR



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