Linux ltrace Guide

Complete beginner-friendly guide to ltrace on Linux, covering Arch Linux, CachyOS, and other distributions including library call tracing, function calls, and debugging.

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Table of Contents

1. ltrace Installation
2. ltrace Basics
3. Tracing Library Calls
4. Filtering
5. Troubleshooting

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ltrace Installation

Install ltrace

Arch/CachyOS:

# Install ltrace
sudo pacman -S ltrace

Debian/Ubuntu:

sudo apt install ltrace

Fedora:

sudo dnf install ltrace

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ltrace Basics

Trace Command

Basic usage:

# Trace command
ltrace ls

# Shows library function calls

Trace Process

Running process:

# Trace running process
ltrace -p PID

# -p = PID (traces process by PID)

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Tracing Library Calls

Library Functions

View calls:

# Show library calls
ltrace ls

# Shows:
# - printf()
# - malloc()
# - strcmp()
# - etc.

Summary

Statistics:

# Summary statistics
ltrace -c ls

# -c = count (shows summary)

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Filtering

Filter Functions

Specific functions:

# Filter functions
ltrace -e malloc ls

# -e = trace (only malloc() calls)

Multiple Filters

Multiple functions:

# Multiple filters
ltrace -e malloc,free ls

# Traces multiple functions

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Troubleshooting

ltrace Not Found

Check installation:

# Check ltrace
which ltrace

# Install if missing
sudo pacman -S ltrace

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Summary

This guide covered ltrace usage, library call tracing, and debugging for Arch Linux, CachyOS, and other distributions.

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Next Steps

• strace Guide - System call tracing
• Process Management - Process monitoring
• Debugging - Debugging tools
• ltrace Documentation: man ltrace

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This guide covers Arch Linux, CachyOS, and other Linux distributions. For distribution-specific details, refer to your distribution's documentation.