backtrace - Linux

Overview

The backtrace command generates a stack trace of a running program or process, showing the function calls that led to the current context. This information can be invaluable for debugging errors or understanding code execution flow.

Syntax

backtrace [OPTIONS] [pid]

Options/Flags

  • -a, –all: Print all frames, including those in shared libraries.
  • -c, –count N: Print only the last N frames.
  • -f, –file: Print the file and line number for each frame.
  • -i, –ignored N: Ignore the first N frames (main and wrapper functions).
  • -o, –output FILE: Write output to specified file.
  • -s, –symbols: Resolve symbols to demangled function names.
  • -t, –threads: Print stack traces for all threads in the process.
  • -v, –verbose: Print additional information, such as arguments and local variables.

Examples

  • Print the last 10 stack frames for the current process: 
    backtrace -c 10
  • Print the full stack trace for process with PID 1234: 
    backtrace 1234
  • Resolve symbols in the stack trace of all threads: 
    backtrace -st
  • Write the stack trace to a file: 
    backtrace -o stack.txt

Common Issues

  • Missing symbols: If symbols are not resolved (-s flag), you may get addresses instead of function names. Ensure that the necessary debug symbols are available.
  • Truncated stack trace: The stack trace may be truncated if the process has exceeded ulimit -c. Increase the limit to allow for more frames.

Integration

  • Use backtrace with tools like gdb for in-depth debugging.
  • Integrate backtrace into scripts or pipelines to automate error reporting.

Related Commands

  • gdb: A powerful debugger that can display stack traces and inspect memory.
  • strace: A tool that traces system calls and can provide context for stack frames.