awk send email if

Question

With the following litte awk script, I get an email notification. But I want to get this email only if $1 is greater or equal than 100.

At which position must I put the if statement? I tried many versions without success. Following my script:

awk '

BEGIN{print "Subject:SASL Spam\nFrom:Server.de <test@emailer.com>\nTo:test@emailer.com"}

END{printf("%s\015\n", $1" | "$2)}

' /home/web0/html/tools/uptime/sasl.txt | /usr/lib/sendmail -t test@emailer.com

Answer 1

You can do like this (I shortened it a bit for readabillity):

{ awk 'BEGIN{...} END{...} END{if($1<100){exit(1)}}' file || exit; } > >(sendmail -t ...)

• awk is called in a compound command.
  • if($1<100) checks for the value
  • exit(1) aborts further execution of code inside awk and returns the exit code 1
• || exit this is executed when the awk command returns false (exit code higher than 0). The shell is then exited and no more commands are executed. I don'0t use the pipe | here because that will open a subshell and this subshell is then exited and the next command is executed anyway.
• >(sendmail -t ...) the output is sent to sendmail (if not yet exited).

---

The whole command would then look like:

{ awk 'BEGIN{print "Subject:SASL Spam\nFrom:Server.de <test@emailer.com>\nTo:test@emailer.com"}
  END{printf("%s\015\n", $1" | "$2)} END{if($1<100){exit(1)}}' \
/home/web0/html/tools/uptime/sasl.txt || exit; } > >(/usr/lib/sendmail -t test@emailer.com)

Answer 2

So this uses a single awk statement to prepare an email containing data only from the lines in the source file start with a number >=100, if none of them meet this condition then no email is sent, which is I think what you are trying to achieve. It also makes sure that the first field is numeric in case there is some unexpected text there which might confuse the numeric comparison:

awk '
{
  if ($1~/^[0-9]*$/ && $1>=100) {
    if (BEENHERE!=1) print "Subject:SASL Spam\nFrom:Server.de <test@emailer.com>\nTo:test@emailer.com\n"
    printf("%s\015\n", $1" | "$2); BEENHERE=1
  }
}' /home/web0/html/tools/uptime/sasl.txt  | \
/usr/lib/sendmail -t test@emailer.com