NAME read20 - read a tape produced by the TOPS-20 Dumper Program SYNOPSIS read20 [-f tapefile] [-t] [-x] [-v] [-c] [-T] [-g] [-e expression] [-S ssnums...] [-F filenums...] [string...] DESCRIPTION Read20 reads tapes produced by the TOPS-20 backup and archival program DUMPER, producing directory listings and extracting files. The -t option specifies a directory list- ing, and the -x option specifies extraction. Both actions can be specified. If no string, -e, -F, or -S option is given, every file on the tape is processed. Otherwise, every file with a name that either contains string ..., matches (as in ed(1)) the regular expression expression, or is selected by the -S and -F options will be processed. The last two options are used to select files by saveset number and file number. This is useful when extracting from an archive tape. The most- recently specified saveset number is associated with the specified file numbers. The TOPS-20 filenames are lower- cased before any matching. Note that string is not a gen- eralized pattern, but is just a simple string that is matched against all the characters in the filenames. Spe- cial characters (such as '<' and '>') must be quoted to get past the shell. The UNIX filename of an extracted file is generated from the TOPS-20 filename by stripping off the device name, translat- ing the TOPS-20 directory syntax to a relative directory in UNIX format, and stripping off the generation number, unless the -g flag is given. Directories will be built as needed with protection 775, but any existing directory or its con- tents will not be changed (unless an extracted file replaces one of the same name). The directory listing prints out for every file -- a ``flags'' field which indicates if the file is archived (A), offline (O), or invisible (I) -- the size in TOPS-20 pages (for offline files the size before archiving) -- the number of bytes in the file -- the bytesize (number of bits per byte) of the file -- the octal TOPS-20 file protection -- the time and date the file was last modified -- the full pathname of the file. If the -v flag is given, two additional fields are printed at the left: -- the saveset number -- the file number Read20 only extracts text files and 8-bit files. In text files, unless the -c flag is given, carriage returns preced- ing linefeeds are removed. The file length as printed by the `t' option is not adjusted to account for this. Read20 decides whether or not a file is text by examining the bytesize of the file. If the file has 7-bit bytes, it is assumed to be a text file. If it has 8-bit bytes, it is extracted at 4 bytes/word, including null bytes. If the file has any other bytesize, requests to extract it are ignored. Occasionally, text files have a bytesize of 36 or 0 instead of the proper bytesize of 7. The -T flag forces these files to be considered as text files. Alternate tape devices or files may be specified with the -f flag. The special filename `-' signifies the standard input. On non-Berkeley Unix systems, name collisions can occur when the first 14 characters of extracted files are the same. If this is the case, use the -n <number> option. This will cause the Unix filenames to be numeric, starting with the number following the -n. The mapping from the original TOPS-20 to the numeric Unix filenames is written to the file `` Logfile '' in the current directory. FILES /dev/rmt8 - default tapefile. AUTHOR Jim Guyton, The Rand Corporation Jay Lepreau, University of Utah BUGS Files which span tape boundaries are handled poorly. To extract such a file, extract each piece and then combine the files under UNIX. Directory descriptor blocks on the tape are not interpreted. Offline files usually show up in directory listings with a zero bytesize.