

DELTA (1)                      9/14/81                       DELTA (1)


NAME 
       delta - make a TCS delta

SYNOPSIS 
       delta revision history [newhistory]

DESCRIPTION 
       Delta  integrates the current "revision" of a file into its TCS
       "history"  file  or  into  a  "newhistory"  file.   Differences
       between  this  version  and the preceeding version are computed
       and the TCS file will be able to reproduce either  version  (or
       earlier versions) by means of the GET command. 
       
       The  user  is  requested  to  provide  a reason-for-change when
       prompted by "History?".   Multiple  lines  may  be  entered  to
       describe changes and terminated by '.' on a line by itself. 

FILES 
       A  scratch  file is created during processing, then copied onto
       the "history".  If a "newhistory" is given, the result will  be
       moved there instead. 

SEE ALSO 
       ADMIN, GET. 
       "The  Source  Code  Control  System,  by Marc J. Rochkind, ____IEEE
       ____________Transactions  __on  ________Software  ___________Engineering,  Vol.  SE-1,  No.   4,
       December 1975

EXAMPLES
       delta newversion program.tcs
            Insert    the    "newversion"    of   program   into   the
            TCS-maintained history, kept on "program.tcs"  (which  was
            originally created with "admin"). 

       delta newversion program.tcs new.tcs
            Insert    the    "newversion"    of   program   into   the
            TCS-maintained history, but this time put  the  output  on
            "new.tcs" instead of "program.tcs". 

       Use  "get"  to  retrieve  this,  or  other  versions,  from the
       TCS-maintained file. 

DIAGNOSTICS 
       Usage: delta revision history [newhistory]
                 Correct  calling  format  is  provided  when   called
                 without arguments. 
                 
       TCS Version Number corrupted. 
       Unexpected EOF on history-info scan. 
       Unexpected EOF on history-data scan. 
                 The  TCS code seems to be present but garbled.  Refer
                 to a guru. 
                 
       Sudden death in input
                 An end-of-file  was  detected  while  requesting  the
                 "reason for change". 


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DELTA (1)                      9/14/81                       DELTA (1)


                 
       Revision file is empty
                 Perhaps an incorrect filename was given. 
                 
       History file is empty
                 The  first  formal version is entered by means of the
                 ADMIN command. 
                 
       Files are too big to handle
                 The DIFF  algorithm  table-size  has  been  exceeded.
                 Current   version  supports  files  of  approximately
                 15000-lines. 
                 
       Cannot locate TCS history file. 
                 Unable to read  filename  specified  as  the  history
                 file. 
                 
       Temp file error: (filename)
                 The   tempoary   file   created   during   processing
                 disappeared unexpectedly. 
                 
AUTHORS 
       An Algorithm for Differential File Comparison by  J.W.Hunt  and
       M.D.McIlroy  (BTL  Computing  Science  Technical  Report  #41).
       Original code by Wil Baden;  converted  from  MORTRAN  by  Dave
       Murray.   Modifications  and  conversion  to  BTL-SCCS style by
       Neil Groundwater at Analytic Disciplines Inc. 

BUGS/DEFICIENCIES 
       File permissions are NOT manipluated  to  restrict  users  from
       disturbing the maintained files. 
       
       Version  numbering  ranges  from  1.1  to 1.N where N is a very
       large number.  Provision  to  increment  the  "primary"  number
       upon demand is scheduled. 
       
       Branching capabilities are scheduled to be implemented. 





















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