This document details the incompatibilites between this version of bash, bash-2.01, and the previous widely-available version, bash-1.14. These were discovered by alpha and beta testers, so they will likely be encountered by a significant number of users. 1. Bash now uses a new quoting syntax, $"...", to do locale-specific string translation. Users who have relied on the (undocumented) behavior of bash-1.14 will have to change their scripts. For instance, if you are doing something like this to get the value of a variable whose name is the value of a second variable: eval var2=$"$var1" you will have to change to a different syntax. This capability is directly supported by bash-2.0: var2=${!var1} This alternate syntax will work portably between bash-1.14 and bash-2.0: eval var2=\$${var1} 2. One of the bugs fixed in the YACC grammar tightens up the rules concerning group commands ( {...} ). The `list' that composes the body of the group command must be terminated by a newline or semicolon. That's because the braces are reserved words, and are recognized as such only when a reserved word is legal. This means that while bash-1.14 accepted shell function definitions like this: foo() { : } bash-2.0 requires this: foo() { :; } This is also an issue for commands like this: mkdir dir || { echo 'could not mkdir' ; exit 1; } The syntax required by bash-2.0 is also accepted by bash-1.14. 3. The options to `bind' have changed to make them more consistent with the rest of the bash builtins. If you are using `bind -d' to list the readline keybindings in a form that can be re-read, use `bind -p' instead. If you were using `bind -v' to list the keybindings, use `bind -P' instead. 4. The `long' invocation options must now be prefixed by `--' instead of `-'. (The old form is still accepted, for the time being.) 5. There was a bug in the version of readline distributed with bash-1.14 that caused it to write badly-formatted key bindings when using `bind -d'. The only key sequences that were affected are C-\ (which should appear as \C-\\ in a key binding) and C-" (which should appear as \C-\"). If these key sequences appear in your inputrc, as, for example, "\C-\": self-insert they will need to be changed to something like the following: "\C-\\": self-insert 6. A number of people complained above having to use ESC to terminate an incremental search, and asked for an alternate mechanism. Bash-2.0 allows ^J to terminate the search without accepting the line. Use ^M to terminate the search and accept the line, as in bash-1.14. 7. Some variables have been removed: MAIL_WARNING, notify, history_control, command_oriented_history, glob_dot_filenames, allow_null_glob_expansion, nolinks, hostname_completion_file, noclobber, no_exit_on_failed_exec, and cdable_vars. Most of them are now implemented with the new `shopt' builtin; others were already implemented by `set'. Here is a list of correspondences: MAIL_WARNING shopt mailwarn notify set -o notify history_control HISTCONTROL command_oriented_history shopt cmdhist glob_dot_filenames shopt dotglob allow_null_glob_expansion shopt nullglob nolinks set -o physical hostname_completion_file HOSTFILE noclobber set -o noclobber no_exit_on_failed_exec shopt execfail cdable_vars shopt cdable_vars 8. `ulimit' now sets both hard and soft limits and reports the soft limit by default (when neither -H nor -S is specified). This is compatible with versions of sh and ksh that implement `ulimit'. The bash-1.14 behavior of, for example, ulimit -c 0 can be obtained with ulimit -S -c 0 It may be useful to define an alias: alias ulimit="ulimit -S"