trace

I am trying to start using erlang:trace/3 and the dbg module to trace the behaviour of a live production system without taking the server down. The documentation is opaque (to put it mildly) and there don't appear to be any useful tutorials online. What I spent all day trying to do was capture what was happening in a particular function by trying to apply a trace to module:function using dbg:c and dbg:p but with no success at all... Does anyone have a succinct explanation of how to use trace in a live Erlang system? If you would prefer a graphical tracer then try erlyberly . It allows you to

In a shell script, how do I echo all shell commands called and expand any variable names? For example, given the following line: ls $DIRNAME I would like the script to run the command and display the following ls /full/path/to/some/dir The purpose is to save a log of all shell commands called and their arguments. Is there perhaps a better way of generating such a log? Tom set -x or set -o xtrace expands variables and prints a little + sign before the line. set -v or set -o verbose does not expand the variables before printing. Use set +x and set +v to turn off the above settings. On the first

I am looking for a tool like ltrace or strace that can trace locally defined functions in an executable. ltrace only traces dynamic library calls and strace only traces system calls. For example, given the following C program: #include <stdio.h> int triple ( int x ) { return 3 * x; } int main (void) { printf("%d\n", triple(10)); return 0; } Running the program with ltrace will show the call to printf since that is a standard library function (which is a dynamic library on my system) and strace will show all the system calls from the startup code, the system calls used to implement printf, and