Quick Linux Tip #58 - How to Profile Memory Usage in a Bash Script

Question: My bash script has a memory leak somewhere. How do I profile it?

Try: /usr/bin/time -v bash ./my_script.sh 2>&1 | grep -E 'Maximum|CPU|Elapsed|Voluntary'

Info: /usr/bin/time (GNU binary, not the shell builtin) with -v tracks detailed resource usage. Peak memory usage is shown under Maximum resident set size (Maximum RSS).

Examples:

• $ /usr/bin/time -v ./program 2>time.log  # Log detailed resource statistics
• $ /usr/bin/time -f '%M KB peak, %e sec, %P CPU' ./script.sh  # Custom resource output
• $ valgrind --tool=massif ./program  # Memory profiling for compiled binaries

Note: The shell builtin time provides less detailed information, so /usr/bin/time is useful when you need GNU resource statistics. A high RSS value in a script can indicate that it is holding large files, arrays, or other data in memory. For a true memory-leak investigation, use a dedicated memory profiler such as Massif rather than relying on peak RSS alone.