Trace file access

Find files the process tries to open but cannot find

strace -e trace=openat -e trace=file myapp 2>&1 | grep 'ENOENT'
tool
strace13 commands
tags
stracelinuxdebug

More strace commands

  • Trace network syscalls
    strace -e trace=network,socket curl https://example.com 2>&1 | grep -v '^---'

    Capture all network-related syscalls

  • Syscall count summary
    strace -c -f -S time -p <pid>

    Aggregate syscall counts/time across forks, sorted by time; pinpoints the costly call

  • Decode fds with timing
    strace -yy -T -tt -e trace=%file -p <pid>

    Show paths/sockets behind fds plus per-call duration and timestamps for file ops

  • Stack trace per syscall
    strace -k -e trace=openat -f -p <pid>

    Print user stack on each openat to find which code path opens a file; needs debug symbols

  • Syscall fault injection
    strace -f -e inject=openat:error=ENOENT:when=3 -p <pid>

    Force the 3rd openat to fail with ENOENT to test error handling; chaos testing without code

all 13 strace commands