This is a list of changes that have been made since the 12/28/93 version of ksh. 1. New features in 12/28/93b a. If IFS contains two consecutive identical characters belonging to the [:space:] class, then this character is treated as a non-space delimiter so that each instance will delimit a field. For example, IFS=$'\t\t' will cause two consecutive tabs to delimit a null field. b. The getopts command has a -a name option that specifies a name that will be used for usage messages. 2. New features in 12/28/93e a. The math functions, atan2, hypot, fmod, and pow were added. b. When a shared library is loaded, if the function lib_init() is defined in the library, it is invoked the first time that the library is loaded with builtin -f library. 3. New features in 12/28/93f a. Hostnames in addition to host addresses can be given in /dev/tcp/host/port virtual file names. b. File name completion and expansion now quotes special characters in file names from both emacs and vi edit modes. 4. New features in 12/28/93g a. The pipefail option has been added. With pipefail enabled, a pipeline will not complete until all commands are complete, and the return value will be that of the last command to fail, or zero if all complete successfully. b. When an executable is found on a given path, the appropriate library path variable is prepended with a corresponding library directory. 5. New features in 12/28/93h a. The PATH search algorithm has been modified to look for a file named .fpath in each bin directory and if found, to search for functions in this directory if it cannot find the command in that directory. b. When performing pathname expansion, the shell checks to see whether each directory it reads is case sensitive or not, and performs the matching accordingly. c. The %T format for printing formatted date/time. 6. New features in 12/28/93i a. Most of the built-in commands and ksh itself are now self documenting. Running command --man will produce screen output. Running command --html produces the man page in html format. b. The getopts builtin can process command description strings to produce man pages. 7. Bugs fixed in 12/28/93a for default OPTIONS a. An expansion bug which causes portions of a word after a $((...)) expansion that contains a nested $var expansion to be lost has been fixed. b. A bug that caused a core dump when a script that did not have PWD set and did a cd inside command substitution has been fixed. c. A bug which caused a core dump on some machines when the LANG variable was assigned to has been fixed. d. A bug which incorrectly handled set disciplines that performed arithmetic evaluation when the discipline was called from the arithmetic evaluator has been fixed. e. A bug caused by an EXIT trap inside a function that was executed in a subshell was fixed. f. If foo is a function, and not a program, then command foo now reports that foo isn't found rather than invoking foo. g. The previous version incorrectly listed -A as an invocation option. The -A option is only for set. h. A bug was fixed which caused ksh to loop when execution trace was enabled and the PS4 prompt required command substitution. i. A bug which could cause the job control switch character to be disabled when a script that enabled monitor mode terminated was fixed. j. A bug in the macro expansion global replacement operator //, when the pattern began with a [ or +( has been fixed. k. A bug which prevented ~ expansion from occurring when it was terminated with a colon inside an assignment has been fixed. l. A bug in the dot command which prevented autoload functions from working has been fixed. m. A bug which caused a variable to be unset if the its value were expanded inside a set discipline has been fixed. n. Whence -a now longer reports that a defined function is undefined. o. A bug on some systems in which $0 would be incorrect in scripts invoked by name has been fixed. p. Here documents with an empty body now work. 1. A bug which disabled argument passing and resetting of options for a script invoked by name inside a function has been fixed. r. A bug in which an EXIT trap set the caller of a function would be executed if a command called inside a function was not found has been fixed. s. A bug which allowed a script to trap signals that are ignored at the time that the shell was invoked has been fixed. t. A bug which caused 2<&1- when applied to a shell built-in to leave standard input closed has been fixed. u. A bug which caused the shell to incorrectly parse $() command substitutions with nested case statements has been fixed. 8. Bugs fixed in 12/28/93b for default OPTIONS a. A bug which caused unset RANDOM to dump core has been fixed. b. A bug which prevented return for terminating a profile or ENV file has been fixed. c. A bug which prevented standard input from being directed to /dev/null for background jobs when monitor mode was turned off has been fixed. d. Statements of the form typeset -options var[expr]=value did not perform substitutions on expr as expected. e. A bug which prevented the shell from sending a HUP signal to some background jobs that were not disowned has been fixed. f. A bug which allowed a script to trap signals that are ignored at the time that the shell was invoked by exec has been fixed. g. A bug which could cause a core dump when a discipline function was unset within a discipline was fixed. h. The typeset builtin now accepts a first argument of + or - for compatibility with ksh88. i. For compatibility with ksh88, the results of expansions of command arguments will treat the extended character match characters ()|& as ordinary characters. j. A bug which caused read to fail on a file that was open for read/write with <> when the first operation was print or printf has been fixed. k. When a job is suspended, it is put on the top of the job list as required by the POSIX standard. l. The value of OPTARG when an option that required an argument but didn't have one was incorrect in the case the the option string began with a :. m. A bug which caused the terminal to get into a bad state with some KEYBD traps in vi-mode has been fixed. n. A bug which caused an invalid trap to cause a script to terminate, rather than just return an error, has been fixed. o. Backreferencing sub-expressions in patterns and replacement strings now works. p. A bug in chmod which caused the -R option to fail has been fixed. 9. Bugs fixed in 12/28/93c for default OPTIONS a. The expansion of "$@" was incorrect when $1 was the null string. b. A bug which could incorrectly report a syntax error in a backquoted expression when a $ was preceded by \\ has been fixed. c. A bug which prevented the shell from exiting after reporting an error when failing to open a script has been fixed. d. A bug that could lead to memory corruption when a large here document that required parameter or command substitution was expanded has been fixed. e. A bug that could cause a core dump on some systems after ksh detected an error when reading a function has been fixed. f. A bug which could cause a coprocess to hang when reading from a process that has terminated has been fixed. g. A bug which caused a script to terminate when set -e was on and the first command of and && or || list failed has been fixed. h. A bug with here documents inside $(...) when the delimiter word is an identifier has been fixed. i. A bug which caused $0 to display the wrong value when a script was invoked as an argument to the . command and the eval command has been fixed. j. A bug that could cause the built-in sleep to hang has been fixed. k. A bug introduces in 12/28/93b which caused the backslash to be removed when it was followed by digit inside double quotes in some instances has been fixed. l. A bug which could cause a core dump if ksh was invoked with standard input closed has been fixed. m. A bug which could cause a core dump if typeset -A was specified for an existing variable has been fixed. n. Variables that were unset but had attributes such as readonly and export were not listed with readonly, export and typeset. o. Several problems with signals have been fixed. p. A bug which prevented ulimit -t from working has been fixed. Also, a bug in which failed ulimits could cause a core dump has also been fixed. q. A bug in expansion of the form ${name/#pattern/string} and ${name/%pattern/string} has been fixed. r. A bug which caused read -r on a line that contained only blanks to get a non-null value has been fixed. s. A bug introduced in the 'a' point release in which ${x='\\'} expanded to \ when x was unset has been fixed. t. A bug which prevented a trap on EXIT from being executed when the last command in a script was a function invocation has been fixed. u. A bug which caused an interactive shell ignore input when standard error was redirected to a file with exec, and then restored with exec 2>&1 has been fixed. v. An interactive shell turns on monitor mode even when standard error has been redirected to a file. w. A bug which could cause standard input to be incorrectly positioned for the last command of a script has been fixed. y. A bug in the edit modes which allowed walking back in the history file for more than HISTSIZE commands has beed fixed. z. A bug which could cause a core dump if variable TMPDIR was changed between two command substitutions has been fixed. aa. A bug which prevented a trap on EXIT from being cleared has been fixed. 10. Bugs fixed in 12/28/93d for default OPTIONS a. The \ character was not handled correctly in replacement patterns with ${x/pattern/replace}. b. A bug with read in which the line did not end with a new-line has been fixed. c. A bug in file name generation which sometimes appended a . for filenames that ended in / has been fixed. d. If a process is waited for after a status has been returned by a previous wait, wait now returns 127. e. A bug with hist (fc) -e which prevented a command to re-executed after it had been edited has been fixed. f. A bug which prevented quoting from removing the meaning of unary test operators has been fixed. 11. Bugs fixed in 12/28/93e for default OPTIONS a. Empty command substitutions of the form $() now work. b. whence -v foo now gives the correct result after calling builtin -d foo. c. A bug in right to left arithmetic assignment for which the arithmetic expression (( y = x = 1.5 )) did not yield 1 for y when x was declared typeset -i was fixed. d. printf has been fixed to handle format containing \0 and/or \0145 correctly. In addition, characters following %b in the format string are no longer displayed when the operand contains \c. e. A bug in printf that could cause the %E format to produce unnormalized results has been fixed. f. A bug which causes some arithmetic expressions to be incorrectly evaluated as integer expressions rather that floating point has been fixed. g. Functions defined inside a subshell no longer remain defined when the subshell completes. h. The error message from sh -c ';echo foo' has been corrected. i. The format for umask -S has been changed to agree with the specification in the POSIX standard. j. A bug that caused side effects in subscript evaluation when tracing was enabled for subscripts using ++ or -- has been fixed. k. To conform to the Posix standard getopts has been changed so that the option char is set to ? when it returns with a non-zero exit status. l. The handling of \} inside ${name...} has been fixed so that the \ quotes the }. m. A bug that caused the read builtin to resume execution after processing a trap has been fixed. n. [[ -s file ]] has been fixed so that if file is open by ksh, it is flushed first. o. In some cases attributes and sizes for non exported variables weren't being reset before running a script. p. The value of TMOUT was affected by changes make to it in a subshell. q. The jobs command did not reflect changes make by sending the CONT signal to a command. r. The error message for ksh -o unknown was incorrect. s. Functions invoked as name=value name, did not use values from the calling scope when evaluating value. t. A bug in which the shell would reexecute previously executed code when a shell script or coprocess was run in the background has been fixed. u. A bug in which an empty here-document would leave a file descriptor open has been fixed. v. A bug in which $(set -A array ...) would leave a side effect has been fixed. w. A discipline function for a global variable defined within a function defined with the function keyword, incorrectly created a local variable of the same name and applied the discipline to it. 12. Bugs fixed in 12/28/93f for default OPTIONS a. A bug which would cause the secondary prompt to be displayed when a user entered a literal carriage return has been fixed. b. I bug which caused ksh read -s name to core dump was fixed. c. I bug with the expansion of \} and \] inside double quoted strings that also contained variable expansions has been fixed d. Changes in the 'e' point release caused autoload functions invoked from within command substitution to fail. This has been fixed. e. A bug in the processing of here-documents that could prevent variable substitution to occur after $(...) command substitution for long here documents has been fixed. f. A bug caused by a race condition that could cause SIGTERM to be ignored by a child process has been fixed. g. A bug which prevented the startup of a coprocess immediately after killing a running coprocess has been fixed. h. ulimit foobar, where foobar is not an arithmetic expression, now gives an error message as it did with ksh88 instead of setting the file size limit to 0. i. A bug which could cause an interactive shell to terminate when the last process of a pipeline was a POSIX function was fixed. j. A bug which could cause command substitution of a shell script to core dump has been fixed. k. A security hole was fixed in suid_exec. l. Arithmetic functions such as pow() that take more than one argument, did not work if arguments other than the first contained parenthesized sub-expression. m. The error message from a script containing an incomplete arithmetic expression has been corrected. n. A bug which caused a core dump on some machines when the value of a name reference contained a positional parameter and the name reference was not defined inside a function has been fixed. o. Arithmetic expressions now correctly handle hexidecimal constants. p. A bug in which integer variables could be expanded with a leading 10# when declared with typeset -i multiple times has been corrected. q. A bug in which IFS wasn't correctly restored when set within command substitution has been fixed. r. The _ character is now considered as part of a word with the M-f and M-b emacs directives as it was in ksh88. 13. Bugs fixed in 12/28/93g for default OPTIONS a. A bug in which a name reference could be created to itself and later cause the shell to get into an infinite loop has been fixed. b. A bug in shcomp relating to compound variables was fixed. c. A bug introduced in 'e' in which leading 0's in -Z fields caused the value to be treated as octal for arithmetic evaluation has been fixed. d. A bug when a name reference with a shorter name than the variable it references was the subject of a compound assignment has been fixed. e. A bug which in which assignment to array variables in a subshell could effect the parent shell has been fixed. f. read name?prompt was putting a 0 byte at the end of the prompt on standard error. g. A bug in [[ string1 > string2 ]] when ksh was run with -x has been fixed. k. A bug in which the escape character was not processed correctly inside {...} when brace expansion is enabled has been fixed, for example {\$foo}. l. A bug in line continuation in here-documents has been fixed. m. The default base when not specified with typeset -i is 10 in accordance with the documentation. Previously, the value was determined by the first assignment. n. A parsing bug in which a # preceded alphanumeric characters inside a command substitution caused a syntax error to be reported has been fixed. o. A bug in which a decimal constant represented as 10#ddd where ddd was more than five digits generated a syntax error has been fixed. p. A bug in here document expansion in which ${...} expansions were split across buffer boundaries has been fixed. 14. Bugs fixed in 12/28/93h for default OPTIONS a. I bug in shcomp for compilation of unary operators with [[...]] has been fixed. b. A bug in which the value of $? was changed when executing a keyboard trap has been fixed. c. The handling of SIGCHLD has been changed so that the trap is not triggered while executing trap commands to avoid recursive trap calls. d. I bug in which a local variable in a function declared readonly would generated an error when the function went out of scope has been fixed. e. I bug in which \ entered from the keyboard with the KEYBD trap enabled has been fixed. f. The error message for a misplaced ((, for example print ((3), was often garbled and has been fixed. g. I bug in the KEYBD trap in which escape sequences of the form [#~ were not being handled as a unit has been fixed. h. A bug in which ksh would consider expressions like [[ (a) ]] as syntax errors has been fixed. i. A function defined as foo() without a function body was not reported as a syntax error. j. A bug in which ksh could run out of file descriptors when a stream was repeatedly opened with exec and read from has been fixed. k. A bug introduced when fixing item n from the 'g' point release has been fixed. 15. Bugs fixed in 12/28/93i for default OPTIONS a. A bug in which a script could terminate when getopts encountered an error when invoked inside a function has been fixed. b. When a symbolic link was specified as the name of the script to invoke by name, the value of $0 was set to the real file name rather than the link name in some cases and this has been fixed. 16. Bug fixes for specific non-default option combinations. a. More signal names have been added for Solaris b. A bug fixed for the v directive in vi MULTIBYTE has been fixed. c. Code to for IFS handling of multibyte characters has been added. d. The displaying of multibyte strings in export, readonly, typeset, and execution traces has been fixed. e. A bug with type ahead and KEYBOARD traps with the MULTIBYTE option set has been fixed. f. The k-shell information abstraction database option, KIA, has been revamped for the 'e' point release. g. A bug in brace pattern expansions that caused expressions such as {foo\,bar,bam} to expand incorrectly have been fixed. h. On the U/WIN version for Window 95 and Windows NT, when a directory beginning with a letter followed by a colon is given to cd, it is assumed to be an absolute directory. i. There was a bug in the compile option that does not use fork() in which the current option settings where not propagated to sub-shells. j. A bug in setting .sh.editchar during the KEYBD trap for the MULTIBYTE option was fixed in release 'h'. k. A bug in which the precision given as an argument to printf was not working has been fixed. 17. Other changes to 12/28/93[abcdefghi] a. A couple of minor changes to make adding built-ins easier. b. Variables inside functions are now statically scoped. The previous behavior was never documented. c. A few changes have been made to the name-value library that affect built-ins that use disciplines. The changes allow disciplines to be shared by variables and should make it possible to add new disciplines without recompilation. d. The name-value library interface has undergone significant change for this revision. See the new nval.3 man page. e. Builtin functions can take a third argument which is a void*. f. The nv_scan() function can restrict the scope of a walk to the top scope. Starting in 'f', nv_scan() has an additional pointer argument that is passed to each invoked function. g. Starting with release 'f', an empty for list behave like a for list with null expansions. It produces a warning message with sh -n. h. Starting with release 'f' the code has been modified to work with EBCDIC as well as ASCII. i. Starting with the release 'g', the name-value pair library uses the cdt library rather than the hash library. j. The sh_fun() function now takes third argument which is an argument list for the invoked discipline function or built-in. k. A callback function can be installed which will give notification of file duplications and file closes. 18. Incompatibilities with 12/28/93 version. None intentional.