IRIX Base Documentation 2001 May

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bbbbrrrruuuu((((1111)))) bbbbrrrruuuu((((1111)))) NNNNAAAAMMMMEEEE bru - backup and restore utility SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS bbbbrrrruuuu mmmmooooddddeeeessss [ ccccoooonnnnttttrrrroooollll ooooppppttttiiiioooonnnnssss ] [ sssseeeelllleeeeccccttttiiiioooonnnn ooooppppttttiiiioooonnnnssss ] files DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN _B_r_u is a UUUUNNNNIIIIXXXX filesystem backup utility with significant enhancements over other more common utilities such as _t_a_r, _c_p_i_o, _v_o_l_c_o_p_y, and _d_d. Some of _b_r_u's capabilities include: o Full or incremental backup with quick and easy restoration of files. o Multiple physical volumes per archive. o Data integrity assurance via checksum computation on every archive block. o Ability to properly save and restore directories, symbolic links, block special files, and character special files. o Comparison of archives with current directory hierarchy. o Ability to recover files from corrupted archives or damaged media with minimal data loss. o No inherent maximum archive buffer size. o Improved performance through random access archive I/O when available. o Automatic byte or half word swapping as necessary when reading archives produced on other machines. o Recognition of filename generation patterns in the same form as the shell for files read from an archive. When _f_i_l_e_s are specified on the command line then the actions to be performed are limited to those _f_i_l_e_s. If a named file is a directory then it and all its descendents are used. If no _f_i_l_e_s are specified then the default for writing archives is all files in and below the current directory. The default for reading archives is selection of all files in the archive. If ``-'' is given instead of _f_i_l_e_s then the standard input is read to obtain the file list. This is useful in conjunction with the _f_i_n_d command to provide finer control over files selected for backup. Obviously this mode is only valid when _b_r_u is not also reading its archive from the standard input. If you are doing backups non-interactively (for example, via _c_r_o_n, be sure to read the description of the ----BBBB option below. DDDDEEEEFFFFAAAAUUUULLLLTTTTSSSS Various default parameters, such as archive device name and size, archive buffer size, controlling terminal name, etc. are system dependent. These defaults, along with version, variant, and other miscellaneous internal information may be discovered via the ----hhhh mode. _b_r_u assumes the default tape device to be ////ddddeeeevvvv////ttttaaaappppeeee if no tape device is PPPPaaaaggggeeee 1111 bbbbrrrruuuu((((1111)))) bbbbrrrruuuu((((1111)))) specified using the ----ffff option. For this to work correctly, ////ddddeeeevvvv////ttttaaaappppeeee should be linked to the actual tape device, for ex. ////ddddeeeevvvv////mmmmtttt////ttttppppssss0000dddd6666.... Also there should be an appropriate entry for ////ddddeeeevvvv////mmmmtttt////ttttppppssss0000dddd6666 in the ////eeeettttcccc////bbbbrrrruuuuttttaaaabbbb file. MMMMOOOODDDDEEEESSSS One or more of the following modes must be specified. The order of execution, from highest priority to lowest, is eeeecccciiiittttxxxxddddgggghhhh. ----cccc CCCCrrrreeeeaaaatttteeee a new archive. Forces a new archive to be created regardless of whether one currently exists. Writing starts at the first block. ----dddd DDDDiiiiffffffffeeeerrrreeeennnncccceeeessss between archived _f_i_l_e_s and current _f_i_l_e_s are detected and reported. May be specified more than once, as ----dddddddd ----dddddddddddd or ----dddddddddddddddd to control level of difference checking. When specified as ----dddd _b_r_u reports when it discovers that a regular file's size (st_size) or contents (when compared as byte streams) has changed since the archive was made. When specified as ----dddddddd _b_r_u reports additional differences in modification date (st_mtime) access mode (st_mode), number of links (st_nlink) for non-directory files, differences in the contents of symbolic links, owner id (st_uid), and group id (st_gid). When specified as ----dddddddddddd _b_r_u reports additional differences in host device (st_dev), major/minor device (st_rdev) for special files, and time of last access (st_atime) for regular files. When specified as ----dddddddddddddddd _b_r_u reports all differences except time of last status change (st_ctime is not resettable), major/minor device numbers for non-special files (meaningless), and size differences for directory files (may have empty entries). The ----dddddddddddddddd mode is generally only meaningful during a verification pass with full backups of quiescent filesystems. ----eeee EEEEssssttttiiiimmmmaaaatttteeee media requirements for archive creation with same arguments. Prints estimated number of volumes, number of files to be archived, total number of archive blocks, and total size of archive in kilobytes. If the media size is unknown, unspecified, or set to 0 via the ----ssss flag or the _b_r_u_t_a_b file, it is assumed to be infinite. The ----ZZZZ flag may also be given. If used, every file that would be backed up will be compressed to a temporary file, which may slow down the estimation considerably. When ----ZZZZ,----cccc and ----eeee are all used, each file will be compressed twice, once during the estimation pass, and once while writing to the archive. PPPPaaaaggggeeee 2222 bbbbrrrruuuu((((1111)))) bbbbrrrruuuu((((1111)))) ----gggg Dump archive info block in a form more easily parsed by programs implementing a complete filesystem management package. Performs no other archive actions. Note: when used with ----tttt, and the rewind tape device, this information is printed after the file list. This option will not work when used with ----tttt if the norewind tape device is used, since _b_r_u expects to be positioned at the beginning of the tape archive after the tape device is closed. When a number of _b_r_u archives are written to the same tape, a sequence like that below will work correctly (where # is the position of a particular archive set), listing first the label information, and then the files in the same archive. mt fsf # bru -vgf /dev/nrtape mt bsf 1 bru -vtf /dev/nrtape ----hhhh Print hhhheeeellllpppp summary of options. Also prints some internal information such as version number and default values for archive pathname, media size, archive buffer size, etc. ----iiii IIIInnnnssssppppeeeecccctttt archive for internal consistency and data integrity. When ----vvvvvvvv option is also given, prints information from archive header block. ----tttt List ttttaaaabbbblllleeee of contents of archive. When used with the ----vvvv option will give a verbose table of contents in the same format as the ``ls -l'' command. When used with the ----vvvvvvvv option will also indicate what files are linked to other files, and where symbolic links point to. ----xxxx EEEExxxxttttrrrraaaacccctttt named _f_i_l_e_s from archive. If an archived file is extracted (see ----uuuu option) then the access mode, device id (special files only), owner uid, group uid, access time, and modification time are also restored. If the ----CCCC flag is given (see below), then the owner uid and group uid will be changed to that of the current user. Nonexistent directories are recreated from archived directories if possible, otherwise they are created with appropriate defaults for the current user. Extracted or created directories are initially empty. CCCCOOOONNNNTTTTRRRROOOOLLLL OOOOPPPPTTTTIIIIOOOONNNNSSSS Many of the control options are similar in function to their _t_a_r or _c_p_i_o equivalents. Sizes are specified in bytes. The scale factors MMMM, kkkk, or bbbb, can be used to indicate multiplication by 2**20, 1024, or 512 respectively. Thus ``10k'', ``20b'', and ``10240'' all specify the same number of bytes. PPPPaaaaggggeeee 3333 bbbbrrrruuuu((((1111)))) bbbbrrrruuuu((((1111)))) ----aaaa Do not update the aaaacccccccceeeessssssss times of disk files that have been read while performing other actions. Normally _b_r_u restores the access and modification times of disk files after they have been read to the access and modification times to whatever they were before the read operation. Restoring the times prevents defeat of the mechanism used to track down and remove ``dead'' files that haven't been accessed in any meaningful way recently. Note that this has the side effect that backup programs such as _d_u_m_p(1m) will backup the file, since the _c_t_i_m_e of the file will have been modified; use of ----aaaa is therefore recommended when using _d_u_m_p as your system backup utility. Use of ----aaaa will also slightly speed up backups, since the inode will not be written. ----bbbb _b_s_i_z_e Use _b_s_i_z_e as the archive input/output bbbbuuuuffffffffeeeerrrr size. The minimum is the size of an archive block (2k or 2048 bytes) and the maximum is determined by available memory and I/O device limitations. If _b_s_i_z_e is not an even multiple of 2048 bytes, it will be rounded up. Normally this option is only required with the ----cccc mode since _b_r_u writes this information in the archive header block. If specified, _b_s_i_z_e overrides any existing default value (generally 20k), whether built in or read from the archive header. ----BBBB Useful in shell scripts where _b_r_u is run in the bbbbaaaacccckkkkggggrrrroooouuuunnnndddd with no operator present or not possible, such as when there is no controlling terminal, causing an open of ////ddddeeeevvvv////ttttttttyyyy to fail. Under these conditions, _b_r_u simply terminates with appropriate error messages and status, rather than attempting interaction with the terminal. With this option, _b_r_u will exit, rather than try to open the controlling terminal. In this case, the entire backup must fit on a single tape or other media, as there is no way to ask for a media change. ----CCCC Change the owner (cccchhhhoooowwwwnnnn) and group of each extracted file to the owner uid and group gid of the current user. Normally, _b_r_u will restore the owner and group to those recorded in the archive. This flag causes bru to follow the system default, with extracted files having the same owner and group as the user running _b_r_u, including Root. The ----CCCC option is useful with archives imported from other systems. In general, it should not be used by the operator or system administrator when restoring saved files. Use the ----ttttvvvv option to see the owner and group of files stored in the archive. ----DDDD This option is not implemented, but is still accepted for backward compatibility with scripts that may use it. ----ffff _p_a_t_h Use _p_a_t_h as the archive ffffiiiilllleeee instead of the default. If the _p_a_t_h is ``-'' then _b_r_u uses the standard input for archive reading or standard output for archive writing, as appropriate. If the path is PPPPaaaaggggeeee 4444 bbbbrrrruuuu((((1111)))) bbbbrrrruuuu((((1111)))) remote then it needs to be specified as [_u_s_e_r@]_s_y_s_t_e_m:/_d_e_v/??? The <user@> part of the path is optional, and if none is specified then the user's login is used. The login has to be equivalently mapped to the remote machine if it has a password. ----FFFF FFFFaaaasssstttt mode. In fast mode, checksum computations and comparisons are disabled. This mode is useful when the output of one _b_r_u is piped to the input of another _b_r_u, or when the data integrity of the archive transmission medium is essentially perfect. Archives recorded with fast mode enabled must also be read with fast mode. Also, be aware that some of the automatic features of _b_r_u, such as automatic byte swapping, are not functional in fast mode. ----jjjj Convert aaaabbbbssssoooolllluuuutttteeee pathnames to "." relative pathnames. This option applies only to the ----xxxx mode. ----XXXX Echo relative pathnames as absolute pathnames. This option only valid when used in conjunction with the -x, -j and -v options. ----LLLL _s_t_r LLLLaaaabbbbeeeellll the archive with the specified string _s_t_r. _S_t_r is limited to 63 characters and is usually some meaningful reminder pertaining to the archive contents. ----llll Ignore unresolved lllliiiinnnnkkkkssss. Normally bru reports problems with unresolved links (both regular and symbolic links). This option suppresses all such complaints. ----mmmm Do not cross mmmmoooouuuunnnntttteeeedddd filesystem boundaries during expansion of explicitly named directories. This option applies only to directories named in _f_i_l_e_s. It limits selection of directory descendents to those located on the same filesystem as the explicitly named directory. This option currently applies only to the ----cccc and ----eeee modes. ----pppp PPPPaaaassssssss over files in archive by reading rather than seeking. Normally _b_r_u will use random access capabilities if available. This option forces reading instead of seeks. ----RRRR RRRReeeemmmmooootttteeee files are to be eeeexxxxcccclllluuuuddddeeeedddd from the archive (unless explicitly listed on the command line; remote directories on the command line are backed up as a directory, but files, subdirectories, etc. therein will not be backed up). Filesystems such as the _p_r_o_c(4) filesystem are considered to not be local, based on the information returned by the _s_t_a_t_v_f_s(2) system call. ----ssss _m_s_i_z_e Use _m_s_i_z_e as the media ssssiiiizzzzeeee. The effective media ssssiiiizzzzeeee will be computed from _m_s_i_z_e since it must be integral multiple of the input/output buffer size (see the ----bbbb option). Normally this option is only required with the ----cccc or ----eeee flags since _b_r_u writes this information in the archive header block. If specified, _m_s_i_z_e PPPPaaaaggggeeee 5555 bbbbrrrruuuu((((1111)))) bbbbrrrruuuu((((1111)))) overrides any existing default value, whether built in, read from the _b_r_u_t_a_b file, or read from the archive header. If set to 0, the tape is assumed to be infinite in length, and the archive is written until an error occurs, at which time a new volume is prompted for. ----vvvv Enable vvvveeeerrrrbbbboooosssseeee mode. May be specified more than once, as ----vvvvvvvv, ----vvvvvvvvvvvv, or ----vvvvvvvvvvvvvvvv, to get even more verbosity. ----wwww WWWWaaaaiiiitttt for confirmation. _B_r_u will print the filename, the action to be taken, and wwwwaaaaiiiitttt for confirmation. Any response beginning with 'y' will cause the action to complete. Any other response will abort the action. ----ZZZZ Use 12-bit LZW file compression. This is not the default because not all versions of _b_r_u know how to deal with compressed files. When the ----vvvv option is also selected, the compression ratio for each file is printed as a percentage. When this flag is used in conjunction with the ----tttt option on an archive that contains compressed file, the actual archive file sizes and names are printed, rather than the original values before archiving. Files are compressed into a temporary file in a directory given by the BRUTMPDIR environment variable. If not given, /usr/tmp is used. ----KKKK Required to archive files larger than 2 Gigabytes. _BBBB_rrrr_uuuu will issue a warning and skip such files if the _----_KKKK flag is not specified. Must be used in conjunction with the _----_ZZZZ flag. If _BBBB_rrrr_uuuu can compress the file to a size smaller than 2 Gigabytes, the file will be archived. Otherwise, a warning will be issued and the file will be skipped. FFFFIIIILLLLEEEE SSSSEEEELLLLEEEECCCCTTTTIIIIOOOONNNN OOOOPPPPTTTTIIIIOOOONNNNSSSS The file selection options control which files are selected for processing. Note that some options are only valid with specific modes. ----nnnn_d_a_t_e Select only files nnnneeeewwwweeeerrrr than _d_a_t_e, where this is based on the file modification time (see _ssss_tttt______mmmm_tttt_iiii_mmmm_eeee in _ssss_tttt_aaaa_tttt(2)); the inode modification time is not checked. The _d_a_t_e is given in one of the forms: DD-MMM-YY[YY][,HH:MM:SS] EX: 12-Mar-84,12:45:00 MM/DD/YY[YY][,HH:MM:SS] EX: 3/12/84 MMDDHHMM[YY[YY]] EX: 0312124584 pathname EX: /etc/lastfullbackup The time of day is optional in the first two forms. If present, it is separated from the date with a comma. If YY is less than 39, it is assumed to be in the range 2000-2039. Otherwise, if less than 100, it is assumed to be in the range 1940-1999. The resulting year must be in the range 1970-2038. If _d_a_t_e is really the pathname of a file, then the modification date of that file will be used instead. This is useful in automated backups when a dummy file is ``touched'' to save the PPPPaaaaggggeeee 6666 bbbbrrrruuuu((((1111)))) bbbbrrrruuuu((((1111)))) date of last backup. ----oooo _u_s_e_r Select only files oooowwwwnnnneeeedddd by _u_s_e_r. _U_s_e_r may be specified in one of three ways: o As an ascii string corresponding to a user name in the password file. o As the pathname of a file in which case the owner of that file is used. o As a numeric value (decimal). ----uuuu _f_l_a_g_s When used in conjunction with ----xxxx mode, causes files of type specified by _f_l_a_g_s to be uuuunnnnccccoooonnnnddddiiiittttiiiioooonnnnaaaallllllllyyyy selected regardless of modification times. Normally _b_r_u will not overwrite (supersede) an existing file with an older archive file of the same name. Files which are not superseded will give warnings if vvvveeeerrrrbbbboooosssseeee mode level 2 (----vvvvvvvv) or higher is enabled. Possible characters for _f_l_a_g_s are: bbbb select block special files cccc select character special files dddd select directories llll select symbolic links pppp select fifos (named pipes) rrrr select regular files Selection of directories only implies that their attributes may be modified. Existing directories are never overwritten, this option merely allows their attributes to be set back to some previously existing state. Selection of symbolic links only implies that the contents of the link will be modified. It is currently impossible to change access time, modification time, or the file mode of a symbolic link. EEEEXXXXAAAAMMMMPPPPLLLLEEEESSSS Create (----cccc) a new archive of all files under ``/usr/src'', writing archive to file (----ffff) ``/dev/rmt0'' using multiple tapes with a maximum size (----ssss) of 30 megabytes per tape. bru -c -f /dev/rmt0 -s 30M /usr/src Create (----cccc) a new archive on the default device in the first pass, archiving all files in and below the current directory which have been created or modified (----nnnn) since 3 P.M. on 14-Jan-84. Then do a second pass to verify that there are no differences (----dddd) between the archive and current files. Each file is listed (----vvvv) as it is processed. bru -cvd -n 14-Jan-84,15:00:00 PPPPaaaaggggeeee 7777 bbbbrrrruuuu((((1111)))) bbbbrrrruuuu((((1111)))) Archive all files owned (----oooo) by user ``user1'' using the default archive device. find / -user user1 -print | bru -c - bru -c -o user1 / Copy a directory hierarchy from ``/usr/u1'' to ``/usr/u2''. (cd /usr/u1; bru -cf - ) | (cd /usr/u2; bru -xf -) Extract (----xxxx) the regular file ``/usr/guest/myfile'' unconditionally (----uuuurrrr) from an archive on file (----ffff) ``/dev/rf0''. Since the device size was recorded in the header block, it need not be specified. Note that option arguments do not need to be separated from their corresponding option flag by whitespace. bru -x -ur -f/dev/rf0 ./usr/guest/myfile Extract (----xxxx) all C source files in ``/usr/src/cmd'' that have names beginning with characters 'a' through 'm'. Wait (----wwww) for confirmation before extracting each file. bru -xw '/usr/src/cmd/[a-m]*.c' Inspect (----iiii) a previously created archive on the default device, dumping the contents of the header block for inspection (----vvvvvvvvvvvv) and verifying internal consistency and data integrity of the archive. bru -ivvv Back up the entire root filesystem without crossing mounted (----mmmm) filesystem boundaries. The archive will be written to file (----ffff) ``/dev/rmt0'' using an I/O buffer size (----bbbb) of 10k bytes. cd / bru -cvm -f /dev/rmt0 -b 10k DDDDIIIIAAAAGGGGNNNNOOOOSSSSTTTTIIIICCCCSSSS Most diagnostics are reasonably informative. The most common have to do with meaningless combinations of options, incompatible options, hitting memory or device limits, unresolved file links, trying to archive or restore something to which access is normally denied, or problems with media errors and/or archive corruption. DDDDEEEEVVVVIIIICCCCEEEE TTTTAAAABBBBLLLLEEEE _B_r_u contains an internal table of known devices and their characteristics. This table is dynamically loaded from a data file specified by the environment variable BBBBRRRRUUUUTTTTAAAABBBB, or from /_e_t_c/_b_r_u_t_a_b, or from an internal default description if neither of the preceding is found. PPPPaaaaggggeeee 8888 bbbbrrrruuuu((((1111)))) bbbbrrrruuuu((((1111)))) The format of the _b_r_u data file for loadable devices is as follows. Note that the table MUST contain at least one entry and the first entry is the default archive device. Also, the table should contain an entry for the standard input and output, with a name of "-". Entries consist of a device name field, followed by one or more capabilities fields. Entries may span more than one line by escaping the newline at the end of the line with a '\' character ('\' is last character on line before newline). All whitespace (tabs, blanks, newlines, formfeeds) between fields is ignored. The device name field must be the first field in the entry and has the following form: <device name>|<device name>| ... |<device name> example: /dev/rmt[0-2]|/dev/mt[0-2] where each device has the same capabilities as the other devices specified (a class of devices). Regular expressions as described in _r_e_g_e_x_p(3) may be used. Each capability field is of the form: <capability name>=<value> or <boolean flag> example: size=640K REOPEN pwerr=EIO Note that there can be no whitespace between the capability name and the value. Note that a size of 0 is treated specially, see the ----ssss flag description above. Numeric values may be given in absolute form or with a trailing scale factor of: b or B Blocks (512 bytes) k or K Kilobytes (1024 bytes) m or M Megabytes (1024 * 1024 bytes) Error numbers may be given in absolute or symbolic form, as defined in <errno.h>. Currently used capabilities include: Name Type Meaning ______________________________________________________________________ size numeric media size in bytes if known, zero otherwise seek numeric minimum seek resolution, zero if no seeks allowed prerr numeric errno for partial reads pwerr numeric errno for partial writes zrerr numeric errno for zero reads zwerr numeric errno for zero writes PPPPaaaaggggeeee 9999 bbbbrrrruuuu((((1111)))) bbbbrrrruuuu((((1111)))) frerr numeric errno for read of unformatted media fwerr numeric errno for write of unformatted media wperr numeric errno for write protected media reopen boolean close and reopen archive upon media switch noreopen boolean no close and reopen archive upon media switch tape boolean archive device is a tape drive rawtape boolean archive device is a "raw" tape drive used primarily with devices that support multiple block sizes norewind boolean closing does not automatically rewind advance boolean read/writes advance media even when errors occur For instance, an excerpt from /_e_t_c/_b_r_u_t_a_b for SCSI tapedrives is: /dev/r*mt/tps[0-9]d[1-7]nr* \ size=0K seek=0 \ prerr=EIO pwerr=EIO zrerr=ENOSPC zwerr=ENOSPC frerr=0 fwerr=0 \ wperr=EROFS norewind reopen tape rawtape advance # /dev/r*mt/tps[0-9]d[1-7]* \ size=0K seek=0 \ prerr=EIO pwerr=EIO zrerr=ENOSPC zwerr=ENOSPC frerr=0 fwerr=0 \ wperr=EROFS reopen tape rawtape advance # This entry is a generic entry for stdin and stdout. - size=0 seek=0 prerr=0 pwerr=0 zrerr=0 zwerr=0 frerr=0 fwerr=0 wperr=0 The internal table that is used if no file can be found is: /dev/tape* \ size=0k seek=0 \ prerr=EIO pwerr=EIO zrerr=ENOSPC zwerr=ENOSPC frerr=0 fwerr=0 \ wperr=EROFS reopen tape rawtape advance /dev/nrtape* \ size=0k seek=0 \ prerr=EIO pwerr=EIO zrerr=ENOSPC zwerr=ENOSPC frerr=0 fwerr=0 \ wperr=EROFS norewind reopen tape rawtape advance SSSSIIIIGGGGNNNNAAAALLLL HHHHAAAANNNNDDDDLLLLIIIINNNNGGGG _B_r_u normally catches both interrupt (SIGINT) and quit (SIGQUIT). When interrupt is caught during archive creation or extraction, _b_r_u completes its work on the current file before cleaning up and exiting. This is the normal way of aborting _b_r_u. When a quit signal is caught an immediate exit is taken. Note that during file extraction, a quit signal may leave the last file only partially extracted. Similarly, a quit signal during archive writing may leave the archive truncated. When either interrupt or quit is caught at any other time an immediate exit is taken. PPPPaaaaggggeeee 11110000 bbbbrrrruuuu((((1111)))) bbbbrrrruuuu((((1111)))) EEEERRRRRRRROOOORRRR RRRREEEECCCCOOOOVVVVEEEERRRRYYYY When properly configured for a given software/hardware environment, bru can recover from most common errors. For example, attempts to use unformatted media are detected, allowing substitution of formatted media. Random blocks in an archive can be deliberately overwritten (corrupted) without affecting _b_r_u's ability to recover data from the rest of the archive. When I/O errors are detected, retries are performed automatically. Out of order sequencing on multi-volume archive reads is detected, allowing replacement with the correct volume. DDDDIIIIRRRREEEECCCCTTTTOOOORRRRIIIIEEEESSSS When creating non-incremental archives _b_r_u automatically archives all directories necessary to fully restore any file from the archive. During extraction, any required directories which do not already exist are restored from the archive if possible, otherwise they are created with appropriate defaults for the current user. The net result is that restoration from incremental archives (which may not contain all necessary directories), or incremental restoration from full archives (which may skip directories needed later), may result in creation of directories with the default attributes. WWWWIIIILLLLDDDDCCCCAAAARRRRDDDDSSSS When rrrreeeeaaaaddddiiiinnnngggg archives _b_r_u recognizes filename generation patterns in the same format as the shell. This allows greater flexibility in specifying files to be extracted, compared, or listed. As a special extension to shell type expansion, the sense of the match is reversed for patterns that begin with '!'. Note that the patterns may have to be quoted to prevent expansion by the shell. Also note that patterns are processed independently, without regard for any other patterns that may or may not be present. In particular, "/bin/a* /bin/b*" is equivalent to "/bin/[ab]*", but "/bin/!a* /bin/!b*" is equivalent to "/bin/*", nnnnooootttt "/bin/![ab]*". BBBBYYYYTTTTEEEE////WWWWOOOORRRRDDDD SSSSWWWWAAAAPPPPPPPPIIIINNNNGGGG While reading archives produced on other machines, _b_r_u automatically attempts to perform byte and/or word swapping as necessary. If no device table is specified, _b_r_u automatically uses the no-swap tape device, which provides higher performance and compatibility with non-byte swapped tapes from other systems. The IRIS 3000 series does not support non-byte swapped tapes, but the automatic byte-swapping capabilities of _b_r_u will deal with this problem. RRRREEEEMMMMOOOOTTTTEEEE TTTTAAAAPPPPEEEE DDDDRRRRIIIIVVVVEEEESSSS _B_r_u allows the use of remote tape drives for the archive device (via the ----ffff option). A remote tape drive filename has the form [_u_s_e_r@]_s_y_s_t_e_m:/_d_e_v/??? where _s_y_s_t_e_m is the remote system, the optional _u_s_e_r is the login name to PPPPaaaaggggeeee 11111111 bbbbrrrruuuu((((1111)))) bbbbrrrruuuu((((1111)))) use on the remote system if different from the current user's login name, and ////ddddeeeevvvv////???????????? is the tape drive to use (1600 BPI or 800 BPI, raw or blocked, rewinding or non-rewinding, etc.). In all cases, the user must have the appropriate permissions on the remote system. (See also the CCCCAAAAVVVVEEEEAAAATTTTSSSS section, below.) EEEEXXXXIIIITTTT CCCCOOOODDDDEEEESSSS _B_r_u always returns meaningful status as follows: 0 Normal exit, no errors or warnings. 1 Warnings (or interrupted). 2 Errors (or quit signal). SSSSEEEEEEEE AAAALLLLSSSSOOOO cpio(1), rmt(1M), tar(1), attr(1), xfsdump(1). UUUUNNNNIIIIXXXX SSSSYYYYSSSSTTTTEEEEMMMM IIIINNNNCCCCOOOOMMMMPPPPAAAATTTTIIIIBBBBIIIILLLLIIIITTTTIIIIEEEESSSS _B_r_u recognizes special file types that may be allowed on one type of UUUUNNNNIIIIXXXX system, but not on another. For instance, on a 4.2 BSD system, _b_r_u will extract fifos as plain files (mode 0666, as modified by the _u_m_a_s_k), and issue an appropriate error message. Usually, _b_r_u will issue two messages. The first message will be the more descriptive of the two. Currently, the only different UUUUNNNNIIIIXXXX systems that _b_r_u fully understands are System V, 4.2 BSD, and Pyramid's OSx. CCCCAAAAVVVVEEEEAAAATTTTSSSS Pathnames are limited to 127 characters in length. This could become a chronic problem. Implementation differences complicate the algorithms for automatic detection of end of file on devices. The algorithms can be fooled, hence the ----ssss option. Special files moved to a machine other than their original host will generally be useless and possibly even dangerous. This goes double for symbolic links. When extracting files from archives, patterns used to match directories may result in some unnecessary directories being extracted. For example, if the pattern is ``a/*/c'', and the directory ``a/b'' is encountered in the archive, the directory file ``a/b'' will be extracted since it will be needed when (and if) the file ``a/b/c'' is encountered. When in doubt, use the ----wwww option. In order to be able to efficiently archive needed directories, _b_r_u builds an image of the directory tree for _f_i_l_e_s using dynamically allocated memory. Since there may be at most 5120 characters passed on the command line, it is very unlikely that _b_r_u will run out of memory while building the tree from command line arguments. This is not true of file lists read from the standard input, particularly on machines with limited address space. PPPPaaaaggggeeee 11112222 bbbbrrrruuuu((((1111)))) bbbbrrrruuuu((((1111)))) Information about file linkages is also kept in memory. Some linkages may be lost if memory is exhausted. Since _b_r_u is owned by root and runs with ``set user id'' to allow it to create directories and special files, it makes every attempt to prevent normal users from archiving or extracting files they would normally not have access to. There may be loopholes. Also note that anyone with physical or electronic access to an archive, and knowledge of the archive structure, can recover any of its contents by writing their own file extraction program. Files within directories which have filesystems mounted on them will not be properly archived until the filesystem is unmounted, since the mounted filesystem hides them. This is not generally a problem. Explicitly naming both a directory and one of its descendents will cause the descendent to be archived twice, unless they are on separate filesystems and the ----mmmm flag is used. Explicitly naming a file more than once is ineffective. When reading from the raw magnetic tape file (rmtxxx) _b_r_u automatically attempts to adjust the I/O buffer size to match that used to record the archive. Under certain circumstances it may fail and require help via the ----bbbb option. Using remote tape drives can be slow. Extended Attributes such as file ACL's, capability sets, and MAC labels are not archived or restored using bru. See _aaaa_tttt_tttt_rrrr(1) for more information about Extended Attributes and see _xxxx_ffff_ssss_dddd_uuuu_mmmm_pppp(1m) or _tttt_aaaa_rrrr(1M) with the _----_MMMM option for a method to back them up. PPPPaaaaggggeeee 11113333