Comparison of PC-DCL vs. Open DCL Lite

PC-DCL Cons (for the most part):

• PC-DCL does not have some "important to me" facilities that Accelr8 Open DCL Lite does have, eg, the following listed in decreasing order of importance to me:
  • no DIFF or SEARCH command,
  • no /EXCLUDE switch on any command,
  • no /WIDTH or /SELECT=SIZE on DIRECTORY command,
  • no /CREATED or /MODIFIED on any command.
  I depend on all of these.
• Lines with TABs in them are oftentimes detected as bad syntax. This is very annoying.
• CREATE file doesn't seem to create ASCII text files in DOS format, but instead in Unix format.  However, can easily convert to DOS format by following the CREATE command with:
       $ gsar -ud just_created_file new_dos_format_file
  as long as UnxUtils are in the PATH.  Also, UnxUtils' SED or GAWK could be used to convert to DOS format.
• DEFINE logical can not handle complicated syntax involving multiple lexicals and/or symbols like I've already defined for Open DCL Lite logicals. This is extremely limiting!!
• DEFINE symbol can not handle complicated syntax involving multiple lexicals and/or symbols like I've already defined for Open DCL Lite symbols. This is extremely limiting!!
• DEFINE SYS$OUTPUT does not behave as expected.
  The sequence:
  • DEFINE SYS$OUTPUT some_file_name,
  • miscellaneous commands which output to SYS$OUTPUT,
  • DEASSIGN SYS$OUTPUT,
  seems to:
  • always output to SYS$OUTPUT.lis, and
  • have locking problems sometimes after the DEASSIGN.
  This is unacceptably limiting to me, since I depend on DEFINE SYS$OUTPUT occasionally.
• DELETE doesn't seem to be able to delete an empty directory.
  It doesn't recognize the *.DIR files, even though they are visible with DIRECTORY as lines containing the string: <DIR>.
• DIFFERENCES is not implemented at all.
  Must rely on Open DCL Lite's DIFFERENCES, Microsoft's FC, UnxUtils DIFF oriented utilities, ComponentSoftware's CSDiff, or some other difference utility.
• DIRECTORY can not be used to display directory files using the *.DIR syntax (like in OpenVMS and Open DCL Lite).  Instead the directory files appear in PC-DCL DIRECTORY listings as lines containing the string: <DIR> -- somewhat similar to how they appear in WinXP's DIR listing.
• DIRECTORY file1,file2,etc syntax -- to display a list of several individual files -- not handled.
• DIRECTORY /DOTFILES /SELECT=SIZE..., /WIDTH switches are missing.
• EXIT has major deficiencies.
  
  • An EXIT which follows the invocation of an external command file (via @) seems to require some other line between the command file invocation and the exit command. A blank line with a single dollar sign, a comment line, a label (and probably most other statements) will serve this purpose.
  • If an EXIT follows a procedure with nested IFs, then some subsequent EXIT inside of an unreached ELSE clause may cause unexpected procedure exit.
  • EXIT does not display VMS-style error messages like Open DCL Lite does, eg, for:
         $ exit 2
         $ exit 8
         $ exit 16
            ...etc...
    
• F$GETSYI returns far fewer values compared to Open DCL Lite.
• F$SEARCH does not work with VMS filespecs..
  And it does not return the full filespec, but instead leaves off the directory spec.
  So it's nowhere near as useful as it should be.
• IFs, especially nested IFs, behave in un-OpenVMS ways.
  • Nested IFs do not work like OpenVMS and Open DCL Lite. They use a different syntax apparently, so many, even mildly complicated, scripts developed for OpenVMS or Open DCL Lite will not work without heavy adaptation. Beware of using PC-DCL with any procedures containing nested IFs.
  • PC-DCL seems to unexpectedly execute certain statements within THEN or ELSE clauses which should not logically be executed. I've encountered this with executing an EXIT inside a "should not be executed" ELSE clause, and a DCL Lite SHELL command inside a "should not be executed" THEN clause. Additionally, I've seen an @ invocation of another command file being incorrectly executed in a then clause which is otherwise skipped. Usually these problems can be worked around by fiddling with the arrangement of the IFs, adding GOTOs, pulling the @ invocation outside of all then/else clauses (except that it seems to work in the THEN clause of an inline IF ... THEN), adding "earlier than would normally be used" EXITs, etc. This problem with PC-DCL makes the programming ugly and hard to read at times, and is one of the main reasons for not using PC-DCL as your primary DCL implementation.
  • IF clause expressions sometimes fail when 3 separate comparison clauses are ORed or ANDed together. For example,
         if (a .eqs. b) .or. (a .eqs. b) .or. (a .eqs. c)
         then do_my_stuff
    croaks with an "Invalid syntax" error. Sometimes they fail, sometimes they don't.
  These nested IF problems, in and of themselves, are reasons for me to not use PC-DCL as my preferred DCL implementation.  But I do have to admit that Michel Valentin himself -- in his HELP / Miscelaneous / "What is PC-DCL ?" topic -- says PC-DCL is suitable for simple DCL command files.
• It's help facility has several problems:
  • It doesn't operate hierarchically the same way that OpenVMS DCL and Accelr8 Open DCL Lite do.
  • It seems to be incomplete sometimes.
  • It's readability is hampered by being right justified (at least part of the time).
  • It displays (at least some) pages as if a /PAGE qualifier had been issued to pause the display after each page. This can be considered both an advantage or a disadvantage. I consider it primarily a disadvantage, since there is not a switch to enable/disable it.
  • It always clears the screen.
  • The command
         $ HELP subject *
    does not work to display all help on that subject.
• A logical which has been defined with another logical, when followed by a colon then filespec, does not always work in situations where it does work in OpenVMS DCL and Accelr8 Open DCL Lite. For example, using this logical definition for PCDCLHELP:
       $ define pcdclhelp sys$dcl:[help]
  neither of these two commands will list any of the directory's help files:
       $ dir pcdclhelp:*.hlp
       $ dir pcdclhelp:open.hlp
  though the following does list all the directory's help files:
       $ dir pcdclhelp:
  This contrasts with the case where the PCDCLHELP logical is defined by:
       $ define pcdclhelp "C:[Progra~1.PCDCL.help]"
  where all three of the above DIR commands work.
• Deleting a local symbol with DELETE/SYMBOL xxxx will delete all symbols, both local and global, which contain the same xxxx substring at the beginning of their string name.
  For example,
       $ show symbol xxxx
       $ xxxx111 == "This_Is_Global_String_1"
       $ xxxx222 :== This is global string 2
       $ xxxx := I-am-ZEE-local-STRINGEE
       $ show symbol xxxx
       xxxx111 == This_Is_Global_String_1
       xxxx222 == THIS IS GLOBAL STRING 2
       xxxx == I-AM-ZEE-LOCAL-STRINGEE
       $ delete/symbol xxxx
       $ show symbol xxxx
       $ show symbol xxxx111
       $ show symbol xxxx222
  OpenVMS DCL and Accelr8 Open DCL Lite do not delete more than one symbol at a time.
• **** CHECK THIS OUT FURTHER THEN UPDATE ****
  It can not handle all 3 filespec formats -- VMS, Windows (backslash) and Unix (forward slash) -- simultaneously in a single command, judging from its dcl.ini. PC-DCL can only be in VMS filespec mode or Windows/Unix filespec mode, but not both at the same time. For example, you couldn't do a copy where the source was in VMS format, but the destination was in Windows format.
• **** CHECK THIS OUT FURTHER THEN UPDATE ****
  There is apparently no difference between the := and :== string assignment operators. They both apparently put the result in the global symbol table.
• RECALL /ALL doesn't have a way of clearly showing all the commands in only the present PC-DCL session like DCL Lite can (though PC-DCL's RECALL /ALL is, in general, much better than DCL Lite's).
• RENAME names all output files in upper case, even when filenames with lower case characters are enclosed in double quotes.
• SEARCH is not implemented at all.
  Must rely on Open DCL Lite's SEARCH, Microsoft's FIND or FINDSTR, UnxUtils' GREP oriented utilities or GSAR, ActivePerl's SEARCH.BAT, Digital Mars' GREP [not free], or some other search utility.
• Command line overflow usually inhibits PC-DCL's excellent line editing capability..
  In those cases, DCL Lite is far better, since with DCL Lite you can at least edit the "wrapped around" line(s).
  • Using a window of maximum width is a useful, partial workaround for the PC-DCL "command line overflow inhibits line editing" problem.
  • But if the command fits on a single line, then PC-DCL line editing is far superior to Open DCL Lite's.
• It apparently doesn't automatically process all files, since there is an /ALL switch on some commands to enable processing hidden and system files.
• SHOW LOGICAL has a couple deficiencies:
  
  • It will not display wildcarded logicals, eg, SHOW LOG SYS* or SHOW LOG INI*, either by including the asterisk or leaving it off. That's inconvenient. It requires using SHOW LOG to display the entire list of logicals.
  • It will not display all logicals when SHOW LOG * is used (though it will display the entire list via the simpler SHOW LOG command, and that's easy to adapt to).
• SHOW SYMBOL has deficiencies:
  
  • It does not display alphabetically.
  • It does not display a symbol when defined as the null string.
  • It does not display correctly when certain asterisk wildcard formats are used (eg, *ID* to show all symbols that contain ID anywhere in the symbol -- at the beginning, in the middle, or at the end).
  • It does not show the asterisk when the asterisk is used to define a minimal length match (eg, TOD*AY == "DIR/SINCE" to define TOD as the minimal length of the TODAY command).
• It's SHOW TERMINAL and SET TERMINAL commands do not operate like OpenVMS's DCL. For example, SET TERMINAL /PAGE is not available, and SHOW TERMINAL is completely different.
• TYPE SYS$INPUT can not be used as an easy way to display multiple lines.
  This is unfortunate and is another reason why I can't use PC-DCL as my default DCL implementation, since I have a very large amount of HELP documentation that uses the TYPE SYS$INPUT facility.
• /BY_OWNER switch is not implemented.
• Only single equivalence names are allowed per logical in PC-DCL (whereas OpenVMS DCL and Accelr8 Open DCL Lite allow multiple equivalence names per logical).
• My classy CHD implementation (using CHDL.DCL) can not be used because of its extensive use of nested IFs which PC-DCL isn't mature enough to handle. This, in and of itself, is enough for me to decide to not use PC-DCL as my default, everyday shell. But, my simpler CHDL_PCDCL.DCL substitute (for PC-DCL only) does work for lots of the most common directory changes.