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Very slow Tar extraction from tape
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TP(1) General Commands Manual TP(1) NAME
tp - manipulate tape archive SYNOPSIS
tp [ key ] [ name ... ] DESCRIPTION
Tp saves and restores files on DECtape or magtape. Its actions are controlled by the key argument. The key is a string of characters con- taining at most one function letter and possibly one or more function modifiers. Other arguments to the command are file or directory names specifying which files are to be dumped, restored, or listed. In all cases, appearance of a directory name refers to the files and (recursively) subdirectories of that directory. The function portion of the key is specified by one of the following letters: r The named files are written on the tape. If files with the same names already exist, they are replaced. `Same' is determined by string comparison, so `./abc' can never be the same as `/usr/dmr/abc' even if `/usr/dmr' is the current directory. If no file argument is given, `.' is the default. u updates the tape. u is like r, but a file is replaced only if its modification date is later than the date stored on the tape; that is to say, if it has changed since it was dumped. u is the default command if none is given. d deletes the named files from the tape. At least one name argument must be given. This function is not permitted on magtapes. x extracts the named files from the tape to the file system. The owner and mode are restored. If no file argument is given, the entire contents of the tape are extracted. t lists the names of the specified files. If no file argument is given, the entire contents of the tape is listed. The following characters may be used in addition to the letter which selects the function desired. m Specifies magtape as opposed to DECtape. 0,...,7 This modifier selects the drive on which the tape is mounted. For DECtape, x is default; for magtape `0' is the default. v Normally tp does its work silently. The v (verbose) option causes it to type the name of each file it treats preceded by the function letter. With the t function, v gives more information about the tape entries than just the name. c means a fresh dump is being created; the tape directory is cleared before beginning. Usable only with r and u. This option is assumed with magtape since it is impossible to selectively overwrite magtape. i Errors reading and writing the tape are noted, but no action is taken. Normally, errors cause a return to the command level. f Use the first named file, rather than a tape, as the archive. This option is known to work only with x. w causes tp to pause before treating each file, type the indicative letter and the file name (as with v) and await the user's response. Response y means `yes', so the file is treated. Null response means `no', and the file does not take part in whatever is being done. Response x means `exit'; the tp command terminates immediately. In the x function, files previously asked about have been extracted already. With r, u, and d no change has been made to the tape. FILES
/dev/tap? /dev/mt? SEE ALSO
ar(1), tar(1) DIAGNOSTICS
Several; the non-obvious one is `Phase error', which means the file changed after it was selected for dumping but before it was dumped. BUGS
A single file with several links to it is treated like several files. Binary-coded control information makes magnetic tapes written by tp difficult to carry to other machines; tar(1) avoids the problem. deprecated TP(1)
