Truss like command under Linux to monitor and diagnostic the system calls

In Linux, the strace command is similar to the truss command in Unix, and is used to monitor and diagnose system calls made by a process. It can be used to trace the execution of a program, including the system calls it makes and the signals it receives.

To use the strace command, simply type strace followed by the name of the program you want to trace:

strace program

This will display a trace of the system calls made by the program as it executes. For example:

execve("/usr/bin/program", ["program"], 0x7fffdc8d6e30 /* 62 vars */) = 0
brk(NULL)                               = 0x555555554000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=118495, ...}) = 0
mmap(NULL, 118495, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f57b2c37000
close(3)                                = 0
...

You can also use options to customize the output of the strace command. For example, the -c option can be used to summarize the system call statistics, and the -f option can be used to trace child processes created by the program:

strace -c -f program

For more options and usage examples, you can refer to the strace man page by typing man strace at the command prompt.