Entering the Bash Debugger¶
Invoking the Debugger Initially¶
The simplest way to debug your program is to run bashdb
. Give
the name of your program and its options and any debugger options:
$ cat /etc/profile
if [ "${PS1-}" ]; then
if [ "`id -u`" -eq 0 ]; then
PS1='# '
else
PS1='$ '
fi
fi
fi
if [ -d /etc/profile.d ]; then
for i in /etc/profile.d/*.sh; do
if [ -r $i ]; then
. $i
fi
done
unset i
fi
$ bashdb /etc/profile
For help on bashdb or options, use the --help
option.
$ bashdb --help
Usage:
bashdb [OPTIONS] <script_file>
Runs bash <script_file> under a debugger.
options:
...
Calling the debugger from your program¶
Sometimes it is not feasible to invoke the program from the debugger. Although the debugger tries to set things up to make it look like your program is called, sometimes the differences matter. Also the debugger adds overhead and slows down your program.
Another possibility then is to add statements into your program to call
the debugger at the spot in the program you want. To do this, you source
bashdb/dbg-trace.sh
from where wherever it appears on your filesystem.
This needs to be done only once.
After that you call _Dbg_debugger
.
Here is an Example:
source path-to-bashdb/bashdb/dbg-trace.sh
# work, work, work.
# ... some bash code
_Dbg_debugger
# start debugging here
Since _Dbg_debugger` a function call, it can be nested inside some sort of
conditional statement allowing one to be very precise about the
conditions you want to debug under. And until first call to _Dbg_debugger
,
there is no debugger overhead.
Note that _Dbg_debugger
causes the statement after the call to be stopped at.