intro unix/linux 11
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Transcript of intro unix/linux 11
Lesson 11-Locating, Printing, and Archiving User Files
Overview
Creating a long file.
Splitting long files.
Locating files with find.
Printing a file.
Archiving files.
Creating a Long File
The “ls –R ~” command is used to list all the files contained
in the user’s home directory.
The “cut –c range of characters ~/file name” command is
used to read a particular number of characters from each
line in a file.
The “cat –n file name” command is used to add numbers to
the left of all lines in a copy of the file.
Splitting Long Files
The “split” utility is used to read a long file and break up
the contents into a series of small files of specified size.
Each small file has an extension starting with “aa” and
going through the alphabet as far as needed to hold a copy
of the whole file.
Splitting Long Files
Splitting Long Files into Pieces
Splitting Long Files
Reassembling the files:
The “cat filename*” command is used to read all the small files
and output data that matches the original long file.
The last part of the file names, such as “aa”, “ab”, etc., is in
ASCII order.
The ASCII order is used by the shell for the filenames when it
replaces the * in the command line.
Locating File with Find
The “find” utility is used to locate a particular file in several
directories.
The find utility displays the output and any error message
that is appropriate.
The pathnames of files and information about directories
that cannot be examined because of their assigned
permissions are also displayed by the find utility.
Locating File with Find
The command to be given is “find ~ -name filename –
print”.
The “~” specifies the target starting point directory.
The “–print” specifies that the full pathname of each
occurrence of the file(s) matching the selection criterion
should be output to the screen.
Locating File with Find
Locating files by owner.
Locating and acting on files by owner.
Locating additional options.
Acting on all files in a directory tree.
Locating Files by Owner
The “ls –ld /directory name/$USER” command is used to
determine if the user has a directory with the same name
as the login name in a particular directory.
The “find” utility can also be used to identify files owned by
a particular user.
The output of the find utility can be redirected to a file or a
printer.
Locating Files by Owner
Command Line Interpretation find Utility
Locating and Acting on Files by Owner
The find utility can also be used to remove located files,
change file permissions, or employ any shell file-
manipulation command.
The “-exec” option is used with the utility to execute any
command utilizing the file names that are selected.
Locating and Acting on Files by Owner
Using the find Utility to Locate Files by Owner
Locating Additional Options
Additional Options
Acting on all Files in a Directory Tree
The find utility can be used as an agent to go through the
directory tree recursively and execute another utility on all
files.
The utility shows a user to search through the specified
directory trees, based on a variety of criteria, and perform
actions on the located files.
Printing a File
Printing the output of a pipeline.
Printing multiple copies.
Adding a title line to the banner page.
Checking the status of print jobs.
Canceling a print request.
Printing the Output of a Pipeline
A pipe can be used to connect the output of a utility as an
input to the print utility.
The “col –bx” and the “colcrt” utilities are used to remove
control characters that are of value to the terminal.
Printing Multiple Copies
Any of the following commands can be used to print
multiple copies of a file:
lp –n (number of copies to be printed in numeric value) file
name.
lpr -# (number of copies to be printed in numeric value) file
name.
Adding a Title Line to the Banner Page
A banner page, also called the burst page, contains
information about the printer and the user issuing the print
request.
The “lp –t‘numbers file’ file name” or the “lpr –Pprinter –
J’numbers file’ file name” command can be used to add a
title and print the file.
Adding a Title Line to the Banner Page
The “lp –dprinter –ttitle filename” or the “lpr –Pprinter –
J’title’ filename” are the two formats of the print
commands.
Checking the Status of Print Jobs
All print requests are administered by a spooler.
A spooler is a program that receives print requests from
multiple users and sends jobs one at a time to the printer.
The spooler makes it possible for the system to process
simultaneous print job requests for several users.
The “lpstat” or the “lpq –Pprinter username” command can
be use to examine the queue.
Canceling a Print Request
The “cancel” or the “lprm” command can be used to
remove jobs from the queue.
On a Linux system, all printing jobs owned by the user are
removed from the queue.
On a UNIX system, the “–u” option is used to indicate jobs
owned by the user.
Archiving Files
Archiving files on floppy disks.
Creating archives with tar.
Archiving Files on Floppy Disks
Copying a file to and from a floppy:
Mtools is a set of programs that facilitate the copying of files to a
floppy drive without going through the process of mounting the
drive.
The “mcopy” command is used to copy a file to and from a floppy.
The command requires two arguments the file name from the
current directory, and a:, which is an agreed name for the floppy.
Archiving Files on Floppy Disks
Copying a file to and from a floppy (continued):
Multiple files can be copied by using the * sign in place of a
particular filename.
Attributes such as permissions are not included in the copy.
When a file is copied from a floppy, the permissions for the
newly copied file may not match its original permissions.
When the mcopy command creates a new file on the system,
the default permissions for the new file are applied.
Archiving Files on Floppy Disks
Removing files and directories from a floppy:
The “mdel” command is used to delete files.
The mdel command requires an argument, the name of the
file(s) to be deleted.
The “mdeltree” command is used to delete directories.
This command requires one argument, the name of the
directory to be deleted.
Archiving Files on Floppy Disks
Formatting a floppy disk:
The “mformat” command is used to format a floppy.
The floppy is formatted in the DOS format.
Creating Archives with tar
The “tar” (tape archiving) utility is used extensively for
making archive files on most systems.
The utility can be used to create a single file, called archive,
which contains the files in a directory tree and all
information about each file.
Creating Archives with tar
The command used to create a tar archive is “tar –cvf
filename.tar”.
The command instructs tar to create an archive in verbose
mode and use a file to hold the archive.
The dot (.) is the source directory, from which all files are
archived.
The “tar –tf filename” can be used to list the contents of the tar
archive.
Creating Archives with tar
Extracting files from an archive:
The extension “.tar” is called a “tarball”.
A tarball can be moved, mailed, or placed on portable media.
The “tar –xvf filename.tar” is used to extract the directory tree
from the archive.
The command provides instructions to extract the structure
from the archive in verbose mode, from a file.
Summary
The split utility is used to break the contents of a long file
into a series of small files.
The lp and the lpr utilities manage files directed to the
printer.
The find utility searches through a directory tree for files
based on specific criteria, and then takes action on each
identified file.
Summary
The mtools utility facilitates the copying of files to and from
a floppy drive using a DOS-formatted floppy.
The tar utility is used to make an archive of a directory tree
or a file.
The archive can be stored on permanent media, sent to a
remote machine, or just used to move a structure from one
location in a system to another.