Description:

The mkdir creates directories with the specified names.

Options:

Description:

The rmdir removes empty directories. If any DIRECTORY argument does not refer to an existing empty directory, it is an error.

Options:

Description:

Change the current working directory to dirName.

Description:

The ls command program lists information about files (of any type, including directories). Options and file arguments can be intermixed arbitrarily, as usual.

For non-option command-line arguments that are directories, by default ls lists the contents of directories.

Options:

Description:

The cp command copies files (or, optionally, directories). The copy is completely independent of the original. You can either copy one file to another, or copy arbitrarily many files to a destination directory.

If the last argument names an existing directory, cp copies each SOURCE file into that directory (retaining the same name). Otherwise, if only two files are given, it copies the first onto the second. It is an error if the last argument is not a directory and more than two non-option arguments are given.

By default, cp does not copy directories (see -r below).

The cp command generally refuses to copy a file onto itself, with the following exception: if--force --backup is specified with SOURCE and DEST identical, and referring to a regular file, cp will make a backup file, either regular or numbered, as specified in the usual ways.

Options:

Description:

The mv command moves or renames files (or directories). If the last argument names an existing directory, mv moves each other given file into a file with the same name in that directory. Otherwise, if only two files are given, it renames the first as the second. It is an error if the last argument is not a directory and more than two files are given.

Options:

Description:

The rm command removes each given FILE. By default, it does not remove directories.

Options:

Description:

The cat command copies each FILE (means standard input), or standard input if none are given, to standard output.

Options:

Description:

The more command is a filter for paging through text one screen length at a time.

Options:

Description:

The less command is a program similar to more, but which allows backward movement in the file as well as forward movement.

Options:

Description:

The head command prints the first part (10 lines by default) of each FILE; it reads from standard input if no files are given.

If more than one FILE is specified, head prints a one-line header consisting of ==> FILE NAME <== before the output for each FILE.

Options:

Description:

The tail command prints the last part (10 lines by default) of each FILE.

If more than one FILE is specified, tail prints a one-line header consisting of ==> FILE NAME <== before the output for each FILE.

Options:

Description:

The tailf command will print out the last 10 lines of a file and then wait for the file to grow, tailf is extremely useful for monitoring log files on a laptop when logging is infrequent and the user desires that the hard disk spin down to conserve battery life.

Description:

In the simplest case, diff compares the contents of the two files from-file and to file. A file name of - stands for text read from the standard input. As a special case, diff compares a copy of standard input to itself.

Options:

Description:

The GREP command searches the input files for lines containing a match to a given pattern list. When it finds a match in a line, it copies the line to standard output (by default), or does whatever other sort of output you have requested with options. GREP expects to do the matching on text. Since newline is also a separator for the list of patterns, there is no.way to match newline characters in a text.

Options:

Description:

This manual page documents the GNU version of cut. The cut command prints sections of each line of each input file, or the standard input if no files are given. A filename of - means standard input. The sections to be printed are selected by the options.

Options:

Description:

Utility for updating access/modification times of a file to current system time or other specified time, but also useful for creating a new file. The command touch zzz will create a new file of zero length, named zzz , assuming that zzz did not previously exist. Time-stamping empty files in this way is useful for storing date information, for example in keeping track of modification times on a project.

The touch command is equivalent to : >> newfile or >> newfile (for ordinary files).

Options:

Description:

The we command counts the number of bytes, whitespace-separated words, and newlines in each given FILE, or standard input if none are given or for a FILE of ' - '.

The wc prints one line of counts for each file, and if the file was given as an argument, it prints the file name following the counts.

Options:

Description:

The sort command sorts, merges, or compares all the lines from the given files, or standard input if none are given or for a FILE of ' - '. By default, sort writes the results to standard output.

The sort command has three modes of operation: sort (the default), merge, and check for sortedness.

The following options change the operation mode:

Options:

Description:

It prints to stdout the full path of the executables that would have been executed when this argument had been entered at the shell prompt.

Description:

The whatis command searches a set of database files containing short descriptions of system commands for keywords and displays the result on the standard output. Only complete word matches are displayed.

The whatis database is created using the command /usr/sbin/makewhatis.

Description:

Description whereis locates source/binary and manuals sections for specified files. The supplied names are first stripped of leading pathname components and any (single) trailing extension.

Description:

All files accessible in a Unix system are arranged in one big tree, the file hierarchy, rooted at / These files can be spread out over several devices. The mount command serves to attach the file system found on some device to the big file tree. Conversely, the umount(8) command will detach it again.

The standard form of the mount command, is mount -t type device dir This tells the kernel to attach the file system found on device (which is of type type) at the directory dir. The previous contents (if any) and owner and mode of dir become invisible, and as long as this file system remains mounted, the pathname dir refers to the root of the file system on device.

The file /etc/fstab, may contain lines describing what devices are usually mounted where, using which options. This file is used in three ways:

The command mount -a [-t type] (usually given in a bootscript) causes all file systems mentioned in fstab (of the proper type) to be mounted as indicated, except for those whose line contains the noauto keyword. Adding the -F option will make mount fork, so that the filesystems are mounted simultaneously.

When mounting a file system mentioned in fstab, it suffices to give only the device, or only the mount point.

Normally, only the superuser can mount file systems. However, when fstab contains the user option on a line, then anybody can mount the corresponding system.

Thus, given a line /dev/cdrom /cd iso9660 ro, user, noauto, unhide any user can mount the iso9660 file system found on his CDROM using the command.

mount /dev/cdrom or mount /cd

For more details, only the user that mounted a filesystem can unmount it again. If any user should be able to unmount, then use users instead of user in the fstab line.

Description:

The umount command detaches the file system(s) mentioned from the file hierarchy. A file system is specified either by giving the directory where it has been mounted, or by giving the special device on which it lives.

Description:

The find command is an extremely useful command for finding particular groups of files, find descends the directory tree beginning at each pathname and locates the files that meet the specified conditions. The default pathname is the current directory.

Options:

Description:

The fdformat command does a low level format on a floppy disk. The generic floppy devices, /dev/fd0 and /dev/fd1 , will fail to work with fdformat when a non-standard format is being used, or if the format has not been autodetected earlier.

Options:

Description:

The mke2fs command is used to create a Linux second extended file system on a device (usually a disk partition).

Options:

Description:

The mkbootdisk command creates a boot floppy appropriate for the running system. The created boot disk looks for the root filesystem on the device suggested by /etc/fstab. The only required argument is the kernel version put onto the boot floppy.

Description:

Init is the parent of all processes. Its primary role is to create processes from a script stored in the file /etc/inittab. This file usually has entries, which cause init to spawn gettys on each line that users can log in. It also controls autonomous processes required by any particular system. New entries can be added to this file at any time. However, init still waits for one of the above three conditions to occur. To provide for an instantaneous response.