Automatically cancel binary execution when certain output is detected

use a coprocess:

coproc CO { yourcommand; }while read -ru ${CO[0]} linedo    case "$line" in        *somestring*) kill $CO_PID; break ;;    esacdone

Note that if the command buffers its output, as many commands do when writing to a pipe, there will be some delay before the string is detected.

You could use awk:

program | awk '/pattern/{exit}1'

If you also want to print the line containing the pattern, say:

program | awk '/pattern/{print;exit}1'

For example:

$ seq 200 | awk '/9/{print;exit}1'123456789

EDIT: (With reference to your comment, whether the program would stop or not.) Following is a script that would execute in an infinite loop:

n=1while : ; do  echo $n  n=$((n+1))  sleep 1done

This script foo.sh was executed by saying:

$ time bash foo.sh | awk '/9/{print;exit}1'123456789real    0m9.097suser    0m0.011ssys     0m0.011s

As you can see, the script terminated when the pattern was detected in the output.

EDIT: It seems that your program buffers the output. You could use stdbuf:

stdbuf -o0 yourprogram | awk '/pattern/{print;exit}1'

If you're using mawk, then say:

stdbuf -o0 yourprogram | mawk -W interactive '/pattern/{print;exit}1'