I will give an example of running the strace utility, which allows you to track what a process or command is doing at a given moment.
Simple launch:
strace COMMAND
strace -ff COMMAND
Writing the result to a file, with an increase in the length of the line to 512 (default 32):
strace -o /tmp/strace.txt -s 512 COMMAND
Monitoring an already running process:
strace -p PID
To display time before each line:
strace -t -p PID
strace -tt -p PID
strace -ttt -p PID
For example, to make sure a process or command is accessing a specific file:
strace -P /home/ixnfo/test.txt -p PID
strace -P /home/ixnfo/test.txt echo "test" >> /home/ixnfo/test.txt
View Help:
man strace
See also my article:
How on Linux to learn the process PID and terminate it