How to execute (./myscript) inside awk or bash script?

Question

I would like to run a script within an awk command.
I have a code ./myscript that calculates the likelihood between two entities; the results are listed in listfile.txt.
The input for ./myscript is a file with two columns generated randomly.
The purpose here is to know what input file (values) is the best for the calculation.
If the condition (0.01<$8<0.5) is not verified, the code keep running until it gives the best (random input)
I did try this, but it doesn't keep executing the code
./rand_input_generator
./myscript

rms=` awk ' NR==1 {print $8}' listfile.txt`
echo $rms

awk 'BEGIN {
rrr=$rms;
min=0.01;
max=0.5;
    while(rrr > max) {
    while(rrr < min) {
    system("./rand_input_generator");
    system("./myscript.cmd");
}
}
} '

I seems like it doesn't go into a loop at all. any suggestions please?

eewanco · Accepted Answer

I think I see your dilemma. Try this:

function getvalue()
{
    local -a rms
    ./rand_input_generator
    ./myscript

    # No need for invoking gawk -- use bash array
    read -a rms < listfile.txt
    # Output eighth column/word
    echo ${rms[7]}
    # Echo to stderr/terminal
    echo ${rms[7]} 1>&2
}

rrr=$(getvalue)
min=0.01;
max=0.5;

# Let awk do the comparison, and print out "true" command or "false" command,
# evaluate the command, and loop based on return code
while $(awk -v rms="${rrr}" -v min="${min}" -v max="${max}" 'BEGIN {if (rms < min || rms > max) print "true"; else print "false"}'); do
    # Refresh the value
    rrr=$(getvalue)
done

In reality awk is really a string-processing language, not a math language, so I'd recommend this change to the last three lines if you have bc:

# Call bc to evaluate expression, returning 1 or 0 based on result, and check
while [[ $(echo "(${rrr} < ${min}) || (${rrr} > ${max})" | bc) -eq 1 ]]; do
    rrr=$(getvalue)
done

shilch · Answer

Use awk's system function. The return value is the exit code.
!($8 >= 0 && $8 <= 0.05) { system("./myscript") }

Alex · Answer

Use awk's system() function:
Here an example
awk '{printf("%s ",$1); system("myscript " $2)}' file

the example is from this site https://unix.stackexchange.com/questions/72935/using-bash-shell-function-inside-awk

How to execute (./myscript) inside awk or bash script?

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