A poor man's profiler

poormansprofiler.sh

#!/bin/bash
# A poor man's profiler
# Code adapted from https://poormansprofiler.org

set -eu

if [ "$#" -ne 2 ]; then
    echo "Usage: $0 <program> <nsamples>"
    exit 0
fi

filter() {
    # Collapse stack traces and arrange in order of decreasing occurrence
    awk -f poormanstraces.awk | sort | uniq -c | sort -rn
}

# If pidof doesn't find a process ID for the given program name, it exits with
# status 1, causing this script to exit as well (set -e).
pid=$(pidof "$1")
nsamples=$2
sleeptime=0
logfile="${1}_${pid}.log"

for _ in $(seq 1 "$nsamples"); do
    gdb -ex "thread apply all bt" -batch -p "$pid"
    sleep $sleeptime
done | tee "$logfile" | filter

poormanstraces.awk

# Collapse stack traces collected with gdb
# Code adapted from https://poormansprofiler.org

# Begin with empty stack trace
BEGIN { s = "" }

# Every thread prints the previous thread's stack trace
/^Thread/ { if (s != "") { print s; s = "" } }

# Build up stack trace, starting with current frame
/^\#/ { if (s != "") { s = s " | " $4 } else { s = $4 } }

# Must not forget to print the last thread's stack trace
END { print s }

ShellChecked