CHAPTER 11 Unix Command Summary
Command/Syntax | What it will do |
---|---|
awk/nawk [options] file | scan for patterns in a file and process the results |
cat [options] file | concatenate (list) a file |
cd [directory] | change directory |
chgrp [options] group file | change the group of the file |
chmod [options] file | change file or directory access permissions |
chown [options] owner file | change the ownership of a file; can only be done by the superuser |
chsh (passwd -e/-s) username login_shell | change the user's login shell (often only by the superuser) |
cmp [options] file1 file2 | compare two files and list where differences occur (text or binary files) |
compress [options] file | compress file and save it as file.Z |
cp [options] file1 file2 | copy file1 into file2; file2 shouldn't already exist. This command creates or overwrites file2. |
cut (options) [file(s)] | cut specified field(s)/character(s) from lines in file(s) |
date [options] | report the current date and time |
dd [if=infile] [of=outfile] [operand=value] | copy a file, converting between ASCII and EBCDIC or swapping byte order, as specified |
diff [options] file1 file2 | compare the two files and display the differences (text files only) |
df [options] [resource] | report the summary of disk blocks and inodes free and in use |
du [options] [directory or file] | report amount of disk space in use |
echo [text string] | echo the text string to stdout |
ed or ex [options] file | Unix line editors |
emacs [options] file | full-screen editor |
expr arguments | evaluate the arguments. Used to do arithmetic, etc. in the shell. |
file [options] file | classify the file type |
find directory [options] [actions] | find files matching a type or pattern |
finger [options] user[@hostname] | report information about users on local and remote machines |
ftp [options] host | transfer file(s) using file transfer protocol |
grep [options] 'search string' argument egrep [options] 'search string' argument fgrep [options] 'search string' argument | search the argument (in this case probably a file) for all occurrences of the search string, and list them. |
gzip [options] file gunzip [options] file zcat [options] file | compress or uncompress a file. Compressed files are stored with a .gz ending |
head [-number] file | display the first 10 (or number of) lines of a file |
hostname | display or set (super-user only) the name of the current machine |
kill [options] [-SIGNAL] [pid#] [%job] | send a signal to the process with the process id number (pid#) or job control number (%n). The default signal is to kill the process. |
ln [options] source_file target | link the source_file to the target |
lpq [options] lpstat [options] | show the status of print jobs |
lpr [options] file lp [options] file | print to defined printer |
lprm [options] cancel [options] | remove a print job from the print queue |
ls [options] [directory or file] | list directory contents or file permissions |
mail [options] [user] mailx [options] [user] Mail [options] [user] | simple email utility available on Unix systems. Type a period as the first character on a new line to send message out, question mark for help. |
man [options] command | show the manual (man) page for a command |
mkdir [options] directory | make a directory |
more [options] file less [options] file pg [options] file | page through a text file |
mv [options] file1 file2 | move file1 into file2 |
od [options] file | octal dump a binary file, in octal, ASCII, hex, decimal, or character mode. |
passwd [options] | set or change your password |
paste [options] file | paste field(s) onto the lines in file |
pr [options] file | filter the file and print it on the terminal |
ps [options] | show status of active processes |
pwd | print working (current) directory |
rcp [options] hostname | remotely copy files from this machine to another machine |
rlogin [options] hostname | login remotely to another machine |
rm [options] file | remove (delete) a file or directory (-r recursively deletes the directory and its contents) (-i prompts before removing files) |
rmdir [options] directory | remove a directory |
rsh [options] hostname | remote shell to run on another machine |
script file | saves everything that appears on the screen to file until exit is executed |
sed [options] file | stream editor for editing files from a script or from the command line |
sort [options] file | sort the lines of the file according to the options chosen |
source file . file | read commands from the file and execute them in the current shell. source: C shell, .: Bourne shell. |
strings [options] file | report any sequence of 4 or more printable characters ending in <NL> or <NULL>. Usually used to search binary files for ASCII strings. |
stty [options] | set or display terminal control options |
tail [options] file | display the last few lines (or parts) of a file |
tar key[options] [file(s)] | tape archiver--refer to man pages for details on creating, listing, and retrieving from archive files. Tar files can be stored on tape or disk. |
tee [options] file | copy stdout to one or more files |
telnet [host [port]] | communicate with another host using telnet protocol |
touch [options] [date] file | create an empty file, or update the access time of an existing file |
tr [options] string1 string2 | translate the characters in string1 from stdin into those in string2 in stdout |
uncompress file.Z | uncompress file.Z and save it as a file |
uniq [options] file | remove repeated lines in a file |
uudecode [file] | decode a uuencoded file, recreating the original file |
uuencode [file] new_name | encode binary file to 7-bit ASCII, useful when sending via email, to be decoded as new_name at destination |
vi [options] file | visual, full-screen editor |
wc [options] [file(s)] | display word (or character or line) count for file(s) |
whereis [options] command | report the binary, source, and man page locations for the command named |
which command | reports the path to the command or the shell alias in use |
who or w | report who is logged in and what processes are running |
zcat file.Z | concatenate (list) uncompressed file to screen, leaving file compressed on disk |