For an executable file or command exec, running this will list all system calls:
$ ptrace exec
To display specific system calls use -e option:
$ strace -e open exec
To save the output to a file use the -o option:
$ strace -o output exec
To find the system calls an active program uses, use the -p option while specifying the pid [how to get pid] :
$ sudo strace -p 1115
To generate a statistics report of all the system calls used, use option -c:
$ strace -c exec