strace is a tool that shows you the system calls and signals called by a program. It is a very useful tool, especially to check what files and libraries are opened, read or written by a program.
$ sudo apt install strace
$ strace ./foobar
You will see that strace prints out every system call made by the program, with its input arguments and its output. However, since this verbose listing is printed to the console, you will find it difficult to view the actual output of the program or to interact with it.
$ strace -o strace.log ./foobar
$ strace -f -o strace.log ./foobar
$ strace -e trace=open -o strace.log ./foobar $ strace -e trace=open,close -o strace.log ./foobar
$ strace -e trace=file -o strace.log ./foobar
The other categories include process, network, signal, ipc, desc and memory. See the strace manpage for more details on these categories.
$ strace -e signal=sigkill,sigint -o strace.log ./foobar
The full list of signals can be seen in
man 7 signal.
$ strace -P /home/joe/somefile -o strace.log ./foobar
Note that strace is clever enough to show all calls related to the file descriptor produced by the particular path too.
$ strace -v -o strace.log ./foobar
$ strace -s 100 -o strace.log ./foobar
$ strace -a 100 -o strace.log ./foobar
$ strace -y -o strace.log ./foobar
Tried with: strace 4.11 and Ubuntu 16.04