Strace

Description

Trace system calls and signals.

Usage

Syntax

usage: strace [-CdffhiqrtttTvVxxy] [-I n] [-e expr]...
             [-a column] [-o file] [-s strsize] [-P path]...
             -p pid... / [-D] [-E var=val]... [-u username] PROG [ARGS]
   or: strace -c[df] [-I n] [-e expr]... [-O overhead] [-S sortby]
             -p pid... / [-D] [-E var=val]... [-u username] PROG [ARGS]

Options

-c

count time, calls, and errors for each syscall and report summary

-C

like -c but also print regular output

-w

summarise syscall latency (default is system time)

-d

enable debug output to stderr

-D

run tracer process as a detached grandchild, not as parent

-f

follow forks, -ff -- with output into separate files

-i

print instruction pointer at time of syscall

-q

suppress messages about attaching, detaching, etc.

-r

print relative timestamp, -t -- absolute timestamp, -tt -- with usecs

-T

print time spent in each syscall

-v

verbose mode: print unabbreviated argv, stat, termios, etc. args

-x

print non-ascii strings in hex, -xx -- print all strings in hex

-y

print paths associated with file descriptor arguments

-h

print help message, -V -- print version

-a column

alignment COLUMN for printing syscall results (default 40)

-b execve

detach on this syscall

-e expr

a qualifying expression: option=[!]all or option=[!]val1[,val2]...

options: trace, abbrev, verbose, raw, signal, read, write

-I interruptible

1: no signals are blocked

2: fatal signals are blocked while decoding syscall (default)

3: fatal signals are always blocked (default if '-o FILE PROG')

4: fatal signals and SIGTSTP (^Z) are always blocked (useful to make 'strace -o FILE PROG' not stop on ^Z)

-o file

send trace output to FILE instead of stderr

-O overhead

set overhead for tracing syscalls to OVERHEAD usecs

-p pid

trace process with process id PID, may be repeated

-s strsize

limit length of print strings to STRSIZE chars (default 32)

-S sortby

sort syscall counts by: time, calls, name, nothing (default time)

-u username

run command as username handling setuid and/or setgid

-E var=val

put var=val in the environment for command

-E var

remove var from the environment for command

-P path

trace accesses to path

Comments

Keywords: strace