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Diffstat (limited to 'README')
| -rw-r--r-- | README | 102 |
1 files changed, 92 insertions, 10 deletions
@@ -5,16 +5,11 @@ THE Z SHELL (ZSH) Version ------- -This is version 5.0.7 of the shell. This is a stable release. -There are minor new features as well as bug fixes since 5.0.6. - -Note in particular there is a security fix to disallow evaluation of the -initial values of integer variables imported from the environment (they -are instead treated as literal numbers). That could allow local -privilege escalation, under some specific and atypical conditions where -zsh is being invoked in privilege elevation contexts when the -environment has not been properly sanitized, such as when zsh is invoked -by sudo on systems where "env_reset" has been disabled. +This is version 5.0.8 of the shell. This is a stable release. +There are no significant new features since 5.0.7, but there +are many bugfixes and some significant internal improvements, notably +a more predictable effect for keyboard interrupts and proper parsing +of $(...) expressions. Installing Zsh -------------- @@ -35,6 +30,93 @@ Zsh is a shell with lots of features. For a list of some of these, see the file FEATURES, and for the latest changes see NEWS. For more details, see the documentation. +Incompatibilites between 5.0.7 and 5.0.8 +---------------------------------------- + +Various arithmetic operations have changed, in particular with respect +to the choice of integer or floating point operations. The new +behaviour is intended to be more consistent, but is not compatible with +the old. + +1) Previously, the modulus operation, `%', implicitly converted the +operation to integer and output an integer result, even if one +or both of the arguments were floating point. Now, the C math +library fmod() operator is used to implement the operation where +one of the arguments is floating point. For example: + +Old behavour: + +% print $(( 5.5 % 2 )) +1 + +New behaviour: + +% print $(( 5.5 % 2 )) +1.5 + + +2) Previously, assignments to variables assigned the correct type to +variables declared as floating point or integer, but this type was +not propagated to the value of the expression, as a C programmer +would naturally expect. Now, the type of the variable is propagated +so long as the variable is declared as a numeric type (however this +happened, e.g. the variable may have been implicitly typed by a +previous assignment). For example: + +Old behaviour: + +% integer var +% print $(( var = 5.5 / 2.0 )) +2.75 +% print $var +2 + +New behaviour: + +% integer var +% print $(( var = 5.5 / 2.0 )) +2 +% print $var +2 + + +3) Previously, the FORCE_FLOAT option only forced the use of floating +point in arithmetic expressions for integer constants, i.e. numbers +typed directly into the expression, but not for variables. Hence +an operation involving only integer variables (or string variables +containing integers) was not forced to be performed with floating point +arithmetic. Now, operations involving variables are also forced to +floating point. For example: + +Old behaviour: + +% unsetopt FORCE_FLOAT +% print $(( 1 / 2 )) +0 +% integer i=1 j=2 +% print $(( i / j )) +0 +% setopt FORCE_FLOAT +% print $(( 1 / 2 )) +0.5 +% print $(( i / j )) +0 + +New behaviour: + +% unsetopt FORCE_FLOAT +% print $(( 1 / 2 )) +0 +% integer i=1 j=2 +% print $(( i / j )) +0 +% setopt FORCE_FLOAT +% print $(( 1 / 2 )) +0.5 +% print $(( i / j )) +0.5 + + Incompatibilities between 5.0.2 and 5.0.5 ----------------------------------------- |