ftp.uv.es/2014.11.ftp.uv.es.tar/ftp.uv.es/pub/msdos/compresores/tar/pdtar.doc

Text File | 1993-06-30 | 14KB | 596 lines

                           _p_d_t_a_r





_D_E_S_C_R_I_P_T_I_O_N


_p_d_t_a_r is an extensive rewriting  of gnu tar (public  domain)
that  provides  for  direct  transfer  of  tar  format files
between SCO Xenix and MSDOS systems.

_p_d_t_a_r options  are both  a subset  and a  superset of  those
provided by Xenix tar.

_U_S_A_G_E


_p_d_t_a_r [-options] [file(s)]

_O_P_T_I_O_N_S


_p_d_t_a_r options are of three forms.

-x

the option x is invoked.

-xNN

the option x is invoked with an associated parameter  set to
the numerical value NN.

-x string

the option x is called  with an associated string  parameter
set to string.

NOTE _p_d_t_a_r does NOT support tar style options  where certain
     flags point to the nth argument.








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_F_U_N_C_T_I_O_N_S


NOTE Use the -h option described  below to verify your  ver-
     sion of _p_d_t_a_r against this documentation. If there is a
     difference, the -h will give the latest options.

[0-9]Take options  for a  default file.   On Xenix  this  is
     /etc/default/tar and under MSDOS /default/tar.

NOTE You must  create your own  MSDOS default file  in Xenix
     format to use this under MSDOS.

-A   Do NOT use absolute names if present (strip leading /).

-c   Create an archive.

-C   Change to a named directory. For example, given

     _p_d_t_a_r -cvf archive.tar . -C ../goodies

     _p_d_t_a_r will archive files  in the current directory  and
     its subdirectories (if any). It will then do a chdir to
     ../goodies  and  archive  all  files  in  it  and   its
     subdirectories.  Files taken from ../goodies  will have
     the form ./file rather than ../goodies/file. Copy under
     MSDOS files that were linked under **IX.

-E   Estimate the number of floppies needed.

-f   The following argument is the archive or device name.

NOTE For MSDOS device  names are given  as a:, b:,  c:, etc.
     _p_d_t_a_r does  NOT  recognize  or  use  the  disk  drivers
     supplied with  MSDOS 3.x.  For  example, if you  have a
     second drive with multiple  drivers that you  reference
     as e:, f:, etc.   depending on density and  tracks, for
     _p_d_t_a_r, you must call the drive b:.

NOTE

NOTE

NOTE _p_d_t_a_r begins writing  a track  0, if  you specify  your
     hard disk as the output device, it will  probably TRASH
     YOUR HARD DISK. Testing whether this is really the case
     is left up to the user as an exercise.

-F   The following argument is the name of a file containing
     a list of  files (or  directories) to be  placed in  or
     extracted from an archive.



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-G   Extracts multiple generations. If a file in the archive
     has the same name  but different modification time  AND
     different size from the current file, the  archive file
     is extracted under the name xxxxxxxx.ggg where xxxxxxxx
     is a  (possibly) modified version  of the  current name
     and ggg is a unique number beginning at 000.

-h   Prints a summary listing of the available functions and
     options.

NOTE This function is operating-system selective.

-knn Specify the archive size (for fixed length  devices) in
     kilobytes. Acceptable values for nn are 360, 720, 1200.

NOTE _p_d_t_a_r actually  operates  in  terms  of  512  character
     blocks, and it is this value that is used for reporting
     archive sizes.

-m   Do NOT restore modification times for extracted files.

-n   Not a  tape or  a  pipe (seeks  can  be used  to  speed
     skips). This is implied by the -k option.

-N   If the local  file is newer  than the archive  file, do
     NOT extract the archive file.

-p   Do not restore the original permissions but rather  use
     the default permission generated by umask().

NOTE SCO  Xenix  documentation  claims  the  -p   option  is
     necessary for restoration of the original  permissions.
     This is backasswards from the way the  program actually
     operates.

-Pnn Strip the leading nn parts of the archive path name.

-T   Do NOT adjust MSDOS times. See below.

-t   Produce a table of contents.

-x   Extract from the archive.

-U   Do NOT  mask MSDOS  permissions  to 0755.   See  "MSDOS
     PERMISSIONS" below.

-Z   Unlink each file as it is added to the archive.

     This option is potentially dangerous.





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*    Any other names on the command line are taken  as files
     (or directories) to be placed  in or extracted from  an
     archive.  During extraction named files  or directories
     limits the extraction to matched items.

NOTE A common error  in this  context is failure  to give  a
     properly literal string  for a desired file  name.  For
     example, if an archive  was made from  a list (such  as
     that produced by find) with names of the form

     ./path/name

     then a restrictive list must be of the form

     ./path

     or

     ./path/name

     Due allowance must be made for the impact of the -A and
     -P options  in  creating  a  restrictive  list  for  an
     extraction.

NOTE A single dash (-) given as a file name implies stdin or
     stdout as appropriate.

NOTE The MSDOS version does NOT currently expand  wildcards.
     If  you are  using the  MKS Toolkit  shell,  names con-
     taining  wildcards  will   be  expanded  but   argument
     truncation is probable.

NOTE Case IS ignored in MSDOS file specifications.

NOTE Directory names  given in a  -F list ARE  expanded.  Be
     careful with the following construct:

     find . -print > filelist

     If the current directory has subdirectories, "filelist"
     will have those directory names plus the files in those
     directories. _p_d_t_a_r will expand the directory names with
     the result  that two  or more copies  of the  files are
     added to the  archive.  The proper  form for  producing
     such a list (unless you want redundancy) is

     find . -type f -print > filelist







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_M_S_D_O_S _T_I_M_E_S


MSDOS and UNIX use  different conventions for giving  a time
and date stamp to files.   Although Turbo C and other  MSDOS
compilers provide functions that mimic **IX  file functions,
a problem remains  because a given  long integer value  (the
way tar  records times)  represents different  "clock" times
for MSDOS and **IX.

_p_d_t_a_r deals  with the  time problem  by comparing  the  **IX
representation of  1989:01:01 with  the MSDOS  version.  The
difference is used to adjust the file time stored in the tar
header. In particular

(a)  an archive made  under MSDOS has header  times adjusted
     so that when the archive  is extracted under **IX,  the
     files will have the same clock times as they  did under
     MSDOS.

(b)  an archive  extracted  under  MSDOS  has  header  times
     adjusted so that the extracted files will have the same
     clock time as they did under **IX.

The **IX version of _p_d_t_a_r  does NOT change times.  The  time
adjustment mechanism may be  turned off with the  -T option.
Generally, even for archives  used entirely under MSDOS,  it
should be left on.

_M_S_D_O_S _P_E_R_M_I_S_S_I_O_N_S


MSDOS  has an  even more  brain-dead permission  system than
**IX.

With archives  created under  **IX, _p_d_t_a_r  lets the  chmod()
function in  Turbo C  map the **IX  permissions to  those of
MSDOS.

With archives  created under  MSDOS, _p_d_t_a_r  gives all  files
permission 0755 unless the -U option is used.  In  this case
the original  MSDOS  permissions are  retained.   With  this
option in  effect, the  usual MSDOS  file is  extracted with
permission 0600 under **IX.


_M_S_D_O_S _N_A_M_E_S







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**IX names are modified, if necessary, to produce acceptable
MSDOS names. The modification rules are:

(1)  Truncate file names to 8 characters.

(2)  Change  any illegal  characters in  file names  to 'z'.
     Translate any periods (other than for a suffix) to '_'.

(3)  Truncate suffixes to 3 characters.

_F_O_R_M_A_T_T_I_N_G _D_I_S_K_S


_p_d_t_a_r works with either Xenix or MSDOS format disks.

Under Xenix, _p_d_t_a_r (and Xenix  tar) will write a proper  tar
format file to either Xenix or MSDOS format.  This  disk can
be read under Xenix with tar  or _p_d_t_a_r and under MSDOS  with
_p_d_t_a_r.

Under MSDOS,  _p_d_t_a_r WITH  THE RAW IO  OPTION can  use either
Xenix or MSDOS  format disks  to write a  proper tar  format
file that can be read with either tar or _p_d_t_a_r under Xenix.

Under MSDOS, _p_d_t_a_r WITHOUT the raw io option writes standard
MSDOS disk files. These can only be processed under MSDOS by
_p_d_t_a_r.

Once a MSDOS format disk has been written with  _p_d_t_a_r rawio,
it will NOT be acceptable for  use as a standard MSDOS  disk
unless you reformat it.

Note carefully the differences between the following cases.

1    _p_d_t_a_r -cvf a:archive.tar -F filelist

     produces an archive on a MSDOS disk in MSDOS format. To
     read this under Xenix you need

     doscp -r a:archive.tar archive.tar

     tar -xvf archive.tar

2    _p_d_t_a_r -cvf a: -k 360 -F filelist

     produces an archive  in Xenix format  (even if the  raw
     disk has been formatted for MSDOS).  To read this under
     Xenix you need only give

     tar -0xv




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     extract the contents.

The converse of this operation  also works for moving  files
to MSDOS from Xenix.


_P_O_R_T_A_B_I_L_I_T_Y


_p_d_t_a_r compiles and runs on the following systems:

4.3 BSD (Sun Workstations)

SCO Xenix (80286 machines)

MSDOS 3.x (AT-class machines)

The code should be portable to any machine with a reasonable
approximation of **IX stdio libraries.

_T_A_P_E_S


_p_d_t_a_r has not been tested with tapes.

_B_L_O_C_K_I_N_G _F_A_C_T_O_R


_p_d_t_a_r uses a variable blocking  scheme ranging from one  (1)
to twenty (20) 512 character blocks.

_E_X_T_E_N_T_S

_p_d_t_a_r follows the SCO  Xenix scheme for splitting  files too
large to fit on a single floppy.

_L_I_N_E _T_E_R_M_I_N_A_T_I_O_N _C_O_N_V_E_N_T_I_O_N_S


_p_d_t_a_r makes  no attempt  to adjust  for the  different  line
terminations of  **IX (LF) and  MSDOS (CRLF).   The Kinmonth
_B_i_b_l_i_o_f_i_l_e system includes a program for this purpose (_u_d_l).
This program can distinguish between text and  binary files,
converting only the former. Unless otherwise specified, con-
verted files retain their preconversion  modification times.
Usage is simple:

_u_d_l -u -f list






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converts  all  text  files  in  list  to  UNIX  conventions.
Changing -u to -d converts  all text files in list  to MSDOS
conventions.

If the  -N (extract  only newer  files) option  of _p_d_t_a_r  is
used,   the  following   sequence  results   in   the  least
processing.

pdtar -Nxf archive > list

pdtar -xf archive

_u_d_l -u -f list

_B_U_G_S


*    Interrupt handling needs improvement.

*    No  good  provision  is  made  for  read/write  errors,
     especially full disks under MSDOS.

     Due to  bugs in MSDOS  or the Turbo  C library,  a full
     disk produces a diagnostic about "file not found."

*    **IX -> MSDOS file conversion could be improved.

*    Wildcards in  file names  are not  expanded when  using
     command.com under MSDOS.

_C_O_P_Y_R_I_G_H_T


SCO Xenix is a product of the Santa Cruz Operation.

MSDOS is  a trademark of  Microsoft, a company  dedicated to
proving that you do not have to have a good product to  make
big bucks.

Turbo C is a  trademark of Borland International,  a company
dedicated to proving that you can lose money with good  pro-
ducts.

The MKS  Toolkit is  a product of  Mortice Kern  Systems and
worth every penny, US or Canadian!

Portions of this program are  dependent on code released  to
the Public Domain by John Gilmore.  The author's  release is
cited below.





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The remainder of the code is (c) 1988 by Earl H.   Kinmonth,
History   Department,  University   of   California,  Davis,
California, 95616.

916-752-1636/916-752-0776

ucbvax!ucdavis!ucdked!cck

NON-COMMERCIAL, NON-MILITARY use permitted.

[Original release in GNU tar code.]

I am the author of all  the code in this program.  I  hereby
place it in the public domain.  If you modify it, or port it
to another system, please send me back a copy, so I can keep
a master source.

 John Gilmore
 Nebula Consultants
 1504 Golden Gate Ave.
 San Francisco, California, USA  94115
 [phone]  voice
 hoptoad!gnu  data
 [e-mail] data

Hoptoad talks to  sun, ptsfa, well, lll-crg,  ihnp4, cbosgd,
ucsfcgl, pyramid.



























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