+Note also the list of incompatibilities in the README file. +
+ ++When the shell is invoked with the base name of a script, for example as +`zsh scriptname', previous versions of zsh have used the name directly, +whereas other shells use the value of $PATH to find the script. The +option PATH_SCRIPT has been added to provide the alternative behaviour. +This is turned on where appropriate in compatibility modes. +
+ ++Parameter expansion has been enhanced to provide the ${NAME:OFFSET} and +${NAME:OFFSET:LENGTH} syntax for substrings and subarrays present in +several other shells. OFFSET always uses zero-based indexing. The only +clash with existing zsh syntax occurs if OFFSET begins with an +alphabetic character or `&', which is not likely. +
+ ++The (D) flag in parameter expansion abbreviates directories in the +substituted value. The (q-) flag does minimal shell quotation of arguments +for maximum human readability of the result. +
+ ++The (Z) flag in parameter expansion is an enhanced version of the (z) +flag that takes an argument indicating how the string to be split +is treated. (Z:c:) parses comments as strings; (Z:C:) parses comments +and strips them; (Z:n:) treats newlines as ordinary whitespace: (z) +has always treated unquoted newlines as shell delimiters and turned them +into semicolons, though this was not previously documented. +
+ ++Numeric expansion with braces has been extended so that a step may be +given, as in {3..9..2}. The step may be negative as may the start and +end of the range (this is also new). +
+ ++The glob qualifier P can be used to add a separate word before each +match. For example, *(P:-f:) produces the command line +`-f file1 -f file2 ...'. +
+ ++Regular expression matches now use the same variables for storing matched +components as shell pattern matching. The function system now provides the +function regexp-replace for replacing text using regular expressions. The +zle widget functions replace-string, replace-string-again, if defined with +regex in the name (e.g. "zle -N replace-regexp replace-string"), perform +regular expression matches. In replacement text \& and \1 have the +standard meaning. +
+ ++The completion system now has a style path-completion. Setting this to +false inhibits completion of paths before the current path component, +e.g. /u/b/z no longer completes to /usr/bin/zsh. This is useful on systems +where this form of completion is pathologically slow due to network +performance. +
+ ++With the MULTIBYTE option, the line editor now highlights bytes in the +input that are not part of a valid character in the current locale in hex +as <XX> for hex digits X; highlighting is controlled by the "special" +keyword in the zle_highlight array. These can be distinguished from +unprintable Unicode characters which also use "special" highlighting as the +latter are always two or four bytes long, e.g. <XXXX>, <XXXXXXXX>. +
+ ++zle_highlight also controls highlighting of a removable completion +suffix, e.g. the "/" automatically appended to directories. This uses +the keyword "suffix". +
+ ++The line editor now sets the variable ZLE_LINE_ABORTED if there is +an error when editing the line. The following code can be used +to create a bindable editor widget to restore the aborted line: + recover-line() { LBUFFER=$ZLE_LINE_ABORTED RBUFFER=; } + zle -N recover-line +and then either bind recover-line to a key sequence or use +`M-x recover-line <RET>'. +
+ ++The parameter ZLE_STATE, available in user-defined line editor widgets, +gives information on the state of the line editor. Currently this is +whether the line editor is in insert or overwrite mode. +
+ ++The new shell option HIST_LEX_WORDS causes history lines read in from +a file to be split in the same way as normal shell lines, instead of +simply on whitespace. It's an option as although the result is more +accurate it can take a long time when the history size is large. +
+ ++The shell option MONITOR can be set in non-interactive shells, and also in +subshells (as created by surrounding commands with parentheses), turning on +job control for that subshell. The initial behaviour of a subshell is +still to turn job control off, however if the new POSIX_JOBS option is set +MONITOR remains active in subshells. +
+ ++The new shell option POSIX_CD, active in emulations of POSIX-based shells, +makes the cd builtin POSIX-compatible. +
+ ++The POSIX_JOBS option already referred to has various other +compatibility enchancements. +
+ ++The new shell option POSIX_STRINGS makes a null character in $'...' +expansion terminate the string, as is already the case in bash. This is +not particularly useful behaviour but may become a POSIX requirement. +
+ ++The new shell option POSIX_TRAPS causes the EXIT trap to behave in the same +way as in other shells, i.e. it is only run when the shell exits. +
+ ++The new shell option SOURCE_TRACE causes the shell to report files +containing shell code that the shell executes directly, i.e. startup files +or files run with the `source' or `.' builtins. +
+ ++The shell option SUN_KEYBOARD_HACK has been supplemented by a more general +mechanism: the KEYBOARD_HACK variable defines the character to be ignored. +
+ ++The module zsh/system has a new "zsystem" builtin whose subcommands perform +system level tasks. Currently "zsystem flock" performs advisory file +locking (for aficionados, this uses the fcntl() system call so works over +the network on Linux). This is a particularly convenient way of locking +files for the length of a subshell. "zsystem supports flock" provides a +test for this feature. +
+ ++There is now a function system for recording and restoring recently +entered directories in a persistent fashion, with support in completion +and (if explicitly installed) dynamic directory expansion. See the +entry for cdr in the zshcontrib manual page. +