Debugging a Program With dbx

Chapter 18

Using dbx With the Korn Shell

The dbx command language is based on the syntax of the Korn Shell (ksh 88), including I/O redirection, loops, built-in arithmetic, history, and command-line editing. This chapter lists the differences between ksh-88 and dbx command language.

If no dbx initialization file is located on startup, dbx assumes ksh mode.

This chapter is organized into the following sections:

• ksh-88 Features Not Implemented
• Extensions to ksh-88
• Renamed Commands

ksh-88 Features Not Implemented

The following features of ksh-88 are not implemented in dbx:

• set -A name for assigning values to array name
• set -o particular options: allexport bgnice gmacs markdirs noclobber nolog privileged protected viraw
• typeset -l -u -L -R -H attributes
• backquote (`...`) for command substitution (use $(...) instead)
• [ [ expr ] ] compound command for expression evaluation
• @(pattern[|pattern] ...) extended pattern matching
• co-processes (command or pipeline running in the background that communicates with your program)

Extensions to ksh-88

dbx adds the following features as extensions:

• $[ p -> flags ] language expression
• typeset -q enables special quoting for user-defined functions
• csh-like history and alias arguments
• set +o path disables path searching
• 0xabcd C syntax for octal and hexadecimal numbers
• bind to change Emacs-mode bindings
• set -o hashall
• set -o ignore suspend
• print -e and read -e (opposite of -r, raw)
• built-in dbx commands

Renamed Commands

Particular dbx commands have been renamed to avoid conflicts with ksh commands.

• The dbx print command retains the name print; the ksh print command has been renamed kprint.
• The ksh kill command has been merged with the dbx kill command.
• The alias command is the ksh alias, unless in dbx compatibility mode.
• addr/fmt is now examine addr/fmt.
• /pattern is now search pattern
• ?pattern is now bsearch pattern.