Output format: -a column alignment COLUMN for printing syscall results (default 40) -i print instruction pointer at time of syscall -o file send trace output to FILE instead of stderr -q suppress messages about attaching, detaching, etc. -r print relative timestamp -s strsize limit length of print strings to STRSIZE chars (default 32) -t print absolute timestamp -tt print absolute timestamp with usecs -T print time spent in each syscall -x print non-ascii strings in hex -xx print all strings in hex -y print paths associated with file descriptor arguments -yy print ip:port pairs associated with socket file descriptors
Statistics: -c count time, calls, and errors for each syscall and report summary -C like -c but also print regular output -O overhead set overhead for tracing syscalls to OVERHEAD usecs -S sortby sort syscall counts by: time, calls, name, nothing (default time) -w summarise syscall latency (default is system time)
Filtering: -e expr a qualifying expression: option=[!]all or option=[!]val1[,val2]... options: trace, abbrev, verbose, raw, signal, read, write -P path trace accesses to path
Tracing: -b execve detach on execve syscall -D run tracer process as a detached grandchild, not as parent -f follow forks -ff follow forks with output into separate files -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)
Startup: -E var remove var from the environment for command -E var=val put var=val in the environment for command -p pid trace process with process id PID, may be repeated -u username run command as username handling setuid and/or setgid
Miscellaneous: -d enable debug output to stderr -v verbose mode: print unabbreviated argv, stat, termios, etc. args -h print help message -V print version
