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sort - Sort-Merge Files

$sort [ –cmu  ] [ –ofile ] [ –yk ] [ –zn ] [ –dfiMnr] [ –btc ]
         [ +pos1 –pos2  ]] [ files ]

Description:

The sort command sorts lines from files.

Options:

–b	ignore leading tabs and spaces
–c	check that the input is in sorted order
–d	sort in dictionary order; only letters, digits, and white-space are significant in comparisons
–f	sort upper and lower case letters together
–i	ignore non-printable characters
–m	merge already sorted files
–M	sort as months. The first three non-blank characters are converted to upper case and compared. (implies –b)
–n	sort by numerical value; blanks, minus signs, and decimal points can also be given (implies –b)
–ofile	send output to file (default standard output)
–r	reverse the sorting order
–tc	set the field separator to c
–u	display only one occurrence of duplicate lines
–y[k]	use k kilobytes of memory to sort (default max)
–zn	use n bytes of buffer for long lines
files	read standard input if files is – or no files given
+pos1 [ –pos2]	sort from pos1 to pos2. If pos2 is not specified, sort from pos1 to the end of line. The format for pos1 and pos2 is: m[.n] [bdfinr]
	m	m fields from start of line (default 0)
	n	n characters from start of field (default 0)
	bdfinr	option applies to the specified key only

tr - Translate Characters

$tr [ –cds ] [ string1 ] [ string2 ]

Description:

The tr command copies standard input to output and translates characters from string1 to characters in string2.

Options:

–c	translate characters not in string1
–d	delete characters in string1 from input
–s	truncate repeated characters from string2

Strings:

[a–z]	specifies a range of characters from a to z
[cn*]	specifies n repetitions of c. If the first digit in n is 0, n interpreted as octal. (default decimal)

uniq - Report Duplicate Lines

$uniq [ –udc [ +n ] [ –n ] ] [ file1 [ file2 ] ]

Description:

The uniq command removes duplicate adjacent lines from file1 and places the output in file2.

Options:

–c	display a count of duplicate lines also
–d	display only duplicate lines once
–u	display only unique lines from the original file
–n	skip first n fields from start of line
+n	skip first n characters from the start of field

wc - Count Characters, Lines and Words

$wc [ –clw ] [ files ]

Description:

The wc command counts the characters, lines, or words in the specified files. A total count for all files is kept.

Options:

–c	display number of characters (default all options)
–l	display number of lines
–w	display number of words
files	read standard input if no files are specified

EXAMPLE COMMANDS

# Execute multiple commands on one line
        % pwd ; ls tmp ; echo "Hello world"
# Run the find command in the background
        % find . -name tmp.out -print &
# Connect the output of who to grep
        % who | grep fred
# Talk to fred if he is logged on
        % ( who | grep fred ) && talk fred
# Send ls output to ls.out
        % ls > ls.out
# Send find standard output and standard error to find.out
        % find / -atime +90 -print >& find.out
# Append output of ls to ls.out; do not check if ls.out exists
        % ls >>! ls.out
# Send invite.txt to dick, jane, and spot
        % mail dick jane spot < invite.txt
# List file names that begin with z
        % ls z*
# List two, three, and four character file names
        % ls {??, ???, ????}
# List file names that begin with a, b, or c
        % ls [a-c]*
# List the files in sam's home directory
        % ls ~sam
# Create an alias for the ls –lR command
        % alias lsl "ls -lR"
# Reexecute last command
        % !!
# Reexecute the last more command
        % !more
# Reexecute the last command, changing adm to sys
        % ^sys^adm
# Reexecute last find command, changing tmp to core
        % !find:*:s/tmp/core
# Set NU to the number of users that are logged on
        % set NU=`who | wc -l`
# Set TOTAL to the sum of 4 + 3
        % @ TOTAL=4 + 3
# Set LBIN to /usr/lbin
        % set LBIN=/usr/lbin
# Unset variable LBIN
        % unset LBIN
# Add /usr/lbin to the path variable
        % set path=($path /usr/lbin)
# Disable filename substitution
        % set noglob
# Display $HOME set to /home/anatole
        % echo '$HOME set to' $HOME
# Display the number of positional parameters
        % echo "There are $#argv positional parameters"
# Display the value of positional parameter 2
        % echo $argv[2]
# Display the number of words in path
        % echo $#path
# Bring background job 3 into the foreground
        % fg %3
# Stop the find job
        % stop %find
# Display all information about current jobs
        % jobs -l
# Terminate job 5
        % kill %5
# Increment variable X
        % @ X=X++
# Set variable X to 20 modulo 5
        % @ X=20 % 5
# Set diagnostic mode
        % csh -x
# Run the dbscript in noexec mode
        % csh -n dbscript
# Display the current directory stack
        % dirs
# Put /usr/spool/uucppublic on the directory stack and cd to it
        % pushd /usr/spool/uucppublic
# Check for new mail every 2 minutes
        % set mail=(120 ~/newmail)
# Set prompt to the command number and current directory
        % set prompt=!`pwd`
# Check if VAR is set to null
        % if ($?VAR) echo "VAR set ok"
# Check if VAR is set to ABC
        % if ($VAR == "ABC" ) echo "VAR set to ABC"
# Check if xfile is empty
        % if (-z xfile ) echo "xfile is empty"
# Check if tmp is a directory
        % if ( -d tmp ) echo "tmp is a directory"
# Check if file is readable and writable
        % if (-r file && -w file ) echo "file ok"
# Set a trap to ignore interrupts
        % onintr -
# Set the file size creation limit to 10 Mbytes
        % limit filesize 10m
# Remove the limitation on the cputime resource
        % unlimit cputime
# Read and execute the commands in .runlog
        % source .runlog
# Disable core dumps
        % limit coredumpsize 0m
# Display the last 10 commands
        % history -r 10
# Add group write permission to the file creation mask
        % umask 013
# Display the first and third fields from file
        % awk '{print $1, $3}' file
# Display the first seven characters of each line in tfile
        % cut –c1–7 tfile
# Display the first and third fields from the /etc/passwd file
        % cut –f1,3 –d":" /etc/passwd
# Display lines in names that begin with A, B, C, or Z
        % egrep '[A–C,Z]*' names
# Display lines from dict that contain four character words
        % egrep '....' dict
# Display password entries for users with the Korn shell
        % grep ":/bin/ksh$' /etc/passwd
# Display number of lines in ufile that contain unix; ignore case
        % grep –c 'unix' ufile
# Display the lengths of field 1 from file
        % nawk '{TMP=length($1); print $TMP}' file
# Display the first ten lines of tfile
        % nawk '{for (i=1; i<10; i++) printf "%s\n", \ getline}' tfile
# List the contents of the current directory in three columns
        % ls | paste d" " – – –
# Display file with all occurrences of The substituted with A
        % sed 's/The/A/g' file
# Display your user name only
        % id | sed 's/).*//' | sed 's/.*(//'
# Display file with lines that contain unix deleted
        % sed '/unix/d' file
# Display the first 50 lines of file
        % sed 50q file
# Sort the /etc/passwd file by group id
        % sort -t":" -n +3 -4 /etc/passwd
# Translate lower case letters in file to upper case
        % cat file | tr a-z A-Z
# Display adjacent duplicate lines in file
        % uniq –d file
# Display the numbers of characters and words in file
        % wc –l file
# Display the number of .c files in the current directory
        % ls *.c | wc -l

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