Truss (Unix)

 is a system tool available on some Unix-like operating systems. When invoked with an additional executable command-line argument, makes it possible to print out the system calls made by and the signals received by this executable command-line argument. As of version , is not part of the Single UNIX Specification (POSIX).
The command was originally developed by Roger Faulkner and Ron Gomes as part of the development of Procfs for System V Release 4. While several names were considered, “” was chosen for being non-ambiguous and easily pronounceable, with multiple meanings, including as an abbreviation for "TRace Unix Syscalls and Signals" or in the sense of “If your program doesn’t work, put it in a truss.”