From: CRDGW2::CRDGW2::MRGATE::"SMTP::CRVAX.SRI.COM::RELAY-INFO-VAX" 27-JUL-1989 11:47 To: MRGATE::"ARISIA::EVERHART" Subj: Re: Anyone have a UNIX-Like CD for VMS Received: From KL.SRI.COM by CRVAX.SRI.COM with TCP; Thu, 27 JUL 89 07:13:20 PDT Received: from ucbvax.Berkeley.EDU by KL.SRI.COM with TCP; Thu, 27 Jul 89 07:10:08 PDT Received: by ucbvax.Berkeley.EDU (5.61/1.37) id AA23632; Thu, 27 Jul 89 06:57:26 -0700 Received: from USENET by ucbvax.Berkeley.EDU with netnews for info-vax@kl.sri.com (info-vax@kl.sri.com) (contact usenet@ucbvax.Berkeley.EDU if you have questions) Date: 27 Jul 89 13:49:53 GMT From: robert@arizona.edu (Robert J. Drabek) Organization: U of Arizona CS Dept, Tucson Subject: Re: Anyone have a UNIX-Like CD for VMS Message-Id: <12874@megaron.arizona.edu> References: <8907242012.AA00554@ucbvax.Berkeley.EDU> Sender: info-vax-request@kl.sri.com To: info-vax@kl.sri.com In article <8907242012.AA00554@ucbvax.Berkeley.EDU>, TNIELAND@FALCON.BERKELEY.EDU (Ted Nieland) writes: > Does anyone have a UNIX-Like CD for VMS? I have several > users who a very used to UNIX and would like to a CD command > that works the same. The last CD posted here was not UNIX > compatible. I know I have heard of some, but I need to get > a hold of one. > > TNIELAND@AAMRL.AF.MIL The following is very Unix compatible. The only caution is (like most of these programs) it doesn't verify that the directory exists, so it is like "set default" it that way. It understands devices and can go up and down any number of levels. Actually understands both Unix and VMS names! "cd ?" gives a quick help message with examples. { - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - A Pascal program to set the default device and directory. Similar to the "cd" (change directory) command of Unix. Accepts both VMS and UNIX directory names. Examples of commands are: cd sub cd dev: cd /a/b cd dev:sub cd [a.b.c] cd dev:/a/b/c cd ../../sub cd dev:[a.b.c] cd It must be used as a foreign command which can be created with: $ CD :== $CSC_DISK:[CSC.BIN]CD.EXE (use your own drive/directory names) Author: Robert J. Drabek May 1989 Department of Computer Science The University of Arizona Tucson, Arizona 85721 Inspired by my own very old CD.COM and by a program written in Pascal by Rotan Hanrahan, February 1989, Dept of Comp Sci, UCD, Dublin Ireland, 1989 which in turn was based on CD.COM which appeared in Pageswapper, March 1982. This program is really much different than the above mentioned inspirations. No history stack is included. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - } program cd(output); const ALLOWED_DIR_DELIMITER = '/'; REAL_DIR_DELIMITER = '.'; HELP_COM = '?'; SET_ERROR = '%CD-F-NODIR, could not change directory to '; MAXPARM_ERROR = '%CD-F-MAXPARM, too many parameters - reenter command with fewer parameters'; type word_type = 0..65535; text_range = 1 .. 255; string = varying[255] of char; { - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - } procedure LIB$Get_Foreign(var Cmd_Line: varying [n] of char); extern; procedure LIB$Set_Logical(%Descr LogNam: varying [n] of char; %Descr Valu: varying [m] of char); extern; procedure LIB$Sys_TrnLog(%Descr LogNam: varying [n] of char; var RetLen: [word] word_type; var Result: varying [m] of char); extern; procedure SYS$SetDDir(newdir: [Class_S] packed array [x..n:Integer] of char; var RetLen: [word] word_type; var CurAdr: [Class_S] packed array [a..b:Integer] of char); extern; { - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - } { do_help Help the novice. } procedure do_help(var disk, directory : string); begin writeln('Current device : ', disk); writeln('Current directory : ', directory); writeln; writeln('Commands:'); writeln(' CD Go to Sys$Login'); writeln(' CD .. Go to parent directory'); writeln(' CD / Go to root directory'); writeln(' CD directory_specification Go to specified directory'); writeln(' CD ? Get help'); writeln; writeln('Specification can be a mixture of VMS and Unix styles, for example :'); writeln(' "cd sub" "cd dev:"'); writeln(' "cd /a/b" "cd dev:sub"'); writeln(' "cd [a.b.c]" "cd dev:/a/b/c"'); writeln(' "cd ../../sub" "cd dev:[a.b.c]"'); writeln(' "cd"') end; { do_help } { fix Modifies the input string to look like a correct VMS directory name even if originally it looked like a Unix name. } procedure fix(var S : string); var i : Integer; begin if S = '/' then S := '[000000]'; { Handle the first `..' pair. } if length(S) >= 2 then if (S[1] = '.') and (S[2] = '.') then S[2] := '-'; { Handle the remaining `..' pairs. } i := index(S, '..'); while i > 0 do begin if length(S) > i + 2 then S := substr(S, 1, i - 1) + '-' + substr(S, i + 2, length(S) - i - 1) else S := substr(S, 1, i - 1) + '-'; i := index(S, '..') end; { Change Unix slashes to VMS dots. } for i := 1 to length(S) do if S[i] = ALLOWED_DIR_DELIMITER then S[i] := REAL_DIR_DELIMITER; { Since we allow silliness like /[a.b], we may need to strip off the leading character. } if length(S) >= 2 then if (S[1] = '.') and (S[2] = '[') then S := substr(S, 2, length(S) - 1); { Finally, bracket the directory name. } if S[1] = '.' then S[1] := '['; if S[1] = '[' then if S[length(S)] <> ']' then S := S + ']' end; { fix } { parse Create the device and directory names from the command line and the current path. Expects the device and directory names to be set to the empty string upon entry. Returns FALSE if the command line appears incorrect. } function parse(var command_line, original_directory, device, directory : string) : boolean; var i : integer; return : boolean; dummy : [word] word_type; untrans_device, trans_device : string; begin return := TRUE; { Must extract the first word on the line, minus any preceeding spaces } command_line := command_line + ' !'; i := 1; while command_line[i] = ' ' do { Skip spaces } i := i + 1; if command_line[i] = '!' then command_line := '' else begin {Get 1st word on line} command_line := substr(command_line, i, length(command_line) - i + 1); i := index(command_line, ' '); if i <> length(command_line) - 1 then return := FALSE else command_line := substr(command_line, 1, i - 1) end; if return <> FALSE then begin { First, we need to create a new device name if there is a colon. } i := index(command_line, ':'); if i <> 0 then begin { create a new device name } { Eliminate leading slashes since they are acceptable. } if command_line[1] = ALLOWED_DIR_DELIMITER then begin command_line := substr(command_line, 2, length(command_line) - 1); i := i - 1 end; untrans_device := substr(command_line, 1, i - 1); LIB$Sys_TrnLog(untrans_device, dummy, trans_device); command_line := substr(command_line, i + 1, length(command_line) - i); if trans_device = untrans_device then { No translation occured. } device := untrans_device + ':' else if length(trans_device) > 2 then begin if substr(trans_device, length(trans_device) - 1, 2) = '.]' then { This came from Rotan's code and I am not sure about all of it. } device := untrans_device + ':' else if trans_device[length(trans_device)] = ']' then begin i := index(trans_device, ':'); if i > 0 then begin device := substr(trans_device, 1, i); directory := substr(trans_device, i + 1, length(trans_device) - i) end else device := untrans_device + ':' end else device := untrans_device + ':' end { of length(trans_device) > 2 } end; { Second, let's create a directory name. } if length(command_line) > 0 then begin fix(command_line); if command_line[1] <> '[' then command_line := '[.' + command_line + ']'; LIB$Sys_TrnLog(command_line, dummy, directory) end end; parse := return end; { parse } { can_cd Verifies that the proposed device/directory combination is accessible; returns FALSE if an error was discovered. } function can_cd(var device, directory, original_directory : string) : boolean; begin { haven't yet discovered the right way to check possible failure } can_cd := TRUE end; { can_cd } { do_cd Modify the Sys$Disk logical name to point to the new device. Use the system call Sys$SetDDir to set the default directory. } procedure do_cd(var device, directory, original_directory : string); begin if length(device) > 0 Then { No point in changing it to ""! } LIB$Set_Logical('SYS$DISK', device); if length(directory) > 0 Then { No point in changing it to ""! } SYS$SetDDir(directory.body, original_directory.length, original_directory.body) end; { do_cd } { - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - } var original_device : string; original_directory : string; new_device : string; new_directory : string; command_line : string; dummy_len : [word] word_type; begin { main - cd } new_device := ''; original_device := 'UnknownDisk'; LIB$Sys_TrnLog('SYS$DISK', dummy_len, original_device); new_directory := ''; SYS$SetDDir(new_directory.body, original_directory.length, original_directory.body); LIB$Get_Foreign(command_line); if length(command_line) = 0 then begin LIB$Sys_TrnLog('SYS$LOGIN', dummy_len, command_line); LIB$Sys_TrnLog(command_line, dummy_len, command_line); if parse(command_line, original_directory, new_device, new_directory) then begin if can_cd(new_device, new_directory, original_directory) then do_cd(new_device, new_directory, original_directory) else writeln(output, SET_ERROR, new_device, new_directory) end end else if command_line = HELP_COM then do_help(original_device, original_directory) else if parse(command_line, original_directory, new_device, new_directory) then if can_cd(new_device, new_directory, original_directory) then do_cd(new_device, new_directory, original_directory) else writeln(output, SET_ERROR, new_device, new_directory) else begin writeln(output, MAXPARM_ERROR); writeln(output); do_help(original_device, original_directory) end end. { main - cd } { - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - } -- Robert J. Drabek Department of Computer Science The University of Arizona Tucson, AZ 85721