Tool List

• awk
• chmod
• compress, uncompress
• date
• diff
• grep
• gzip, gunzip, zcat
• head, tail
• lpr, lpq, lprm
• ls
• man
• pquota
• ps
• pwd
• quota
• sed
• sort
• tar
• wc

Other day-to-day UNIX commands

Few examples

• Who is online

Note that the awk language cannot be fully explained in just few examples. For those people who are interested in more aspects of awk, books on this topic can be found in any computer bookstore.

Here are some examples:

  % awk '{ print $NF : $0}'
  CSC209F is an interesting course.
  [Ctrl-d]
  5: CSC209F is an interesting course.

  % awk '/Ann/' name.list
  MarryAnne
  Ann
  DeAnne

  % finger
  Login    Name                     Host               TTY      Idle LoginTime
  ange     Angela Glinos            cheetah            console    4d Fri 09:26
  at209che Douglas I-Hsi Chen       eddie              pts/46        Tue 09:37
  jdd      John DiMarco             mammoth            pts/41      4 Tue 09:33

  % finger | awk '{ print $1, $3}' 
  ange cheetah
  at209che eddie
  jdd mammoth

See also: sed, grep

chmod

Here's how you can change the permission to something else.

  (original permission, -rw-------)

  % chmod 644 myfile           (now change to -rw-r--r--)
  % chmod a=r myfile           (now change to -r--r--r--)
  % chmod ug+w myfile          (now change to -r--rw-rw-)

Zcat is equivalent to 'uncompress -c'

  % compress myfile            (myfile becomes myfile.Z)
  % uncompress myfile.Z        (myfile.Z becomes myfile)
  % uncompress -c myfile.Z     (dump content of myfile.Z to standard output,
                                myfile.Z does NOT become myfile)
  % zcat myfile.Z              (same as above)
  % zcat myfile.Z > myfile     (redirect stdout to a file)

  % date '+DATE: %m/%d/%y%nTIME: %H:%M:%S'

  (result)
   DATE: 09/28/98
   TIME: 14:45:05

  % diff file1 file2           (basic use of diff)
  % diff -i file1 file2        (tell diff to ignore case)

See also: cmp

grep

  Note: story.txt is the text file to be searched

  % grep green story.txt       (show all lines that contain 'green' in them)
  % grep -i green story.txt    (ignore case for the word 'green')
  % grep -v green story.txt    (show all lines that does not have 'green')
  % grep ^green story.txt      (show all lines that begins with 'green')

Here are some examples:

  % gzip myfile                (produces gzip'ed myfile.gz)
  % gunzip myfile.gz           (restore myfile.gz to myfile)
  % gzip -d myfile.gz          (same as above)
  % gzip -cd myfile.gz         (dump content of myfile.gz to stdout,
                                user can then pipe stdout to more/less)
  % gzip -cd myfile.tar.gz | tar xf -
                               (gunzip and untar the file in one command)

  % head myfile                (output first 10 lines of myfile)
  % head -c 1k                 (output first 1-kilobyte of myfile,
                                subs k with b (byte) or m (megabyte))
  % tail -5 myfile             (output last 5 lines of myfile)
  % head -15 myfile | tail -10 (output line 5 to line 15 of myfile)

Note that the -P option is available to all three programs and can be used to select a printer other than the default one or specified in the PRINTER environment variable. If you don't like to use the -P option every time, modify the PRINTER variable!

Here are some examples:

  % lpr story.txt finale.ps  (prints out story.txt and finale.ps)
  % lpr -Preuse *            (prints all files and redirect to printer 'reuse')
  % lpq                      (show status of default printer)
  % lpq -Preduce             (show status of printer 'reduce')
  % lprm 1023                (remove printing job 1023 from printing queue)

  % ls -a          (list all files including .*)
  % ls -d          (list directory entries instead of contents)
  % ls -i          (list inode of each file)
  % ls -l          (list files in long format)
  % ls .*          (list files begin with .)

  % man man                    (show man's own manual page)
  % man -k jump                (keyword search on 'jump')

See also: lpr, lpq, lprm, quota

ps

  % pwd
  /home/u2/csc209h/a209abcd

See also: pquota

sed

Here are some examples:

  % sed 's/John/Johnson/g' report.txt  (change all occurrence of John to Johnson
                                        in report.txt)
  % sed 'y/abc/ABC/' report.txt        (replace all occurrence of a to A, b to
                                        B and c to C)
  % sed '1,10 d' report.txt            (delete the first 10 lines)

    sort -n             Sort in numeric order
    sort -nr            Sort in reverse numeric order
    sort +      Sort starting at +1-st field
    sort -r             Reverse normal order
    sort -u             Discard duplicates (display unique lines)

  (at one directory above directory 209, do the following)

  % tar cf 209.tar 209        (create a tar file 209.tar which contains
                               everything in the directory 209)

  (with newer version of tar, you can gzip the tar file in a single command)

  % tar czf 209.tar.gz 209

  (now, untar/restore the tar file back to the file system)

  % tar xf 209.tar

  -OR-

  % cat 209.tar | tar xf -    (tar takes input from stdin)

  -OR-

  % tar xzf 209.tar.gz

  % wc myfile                  (output number of chars, words and lines)
  % wc -c myfile               (output number of characters only)
  % wc -l myfile               (output number of lines only)
  % wc -w myfile               (output number of words only)

Few examples

  % finger | grep -v ^Login | awk '{ print $1}' | sort -u
  a209witt
  a209zhou
  a2501pyk
  a270cost
  a270razv
  a324anis

  % finger | grep -v ^Login | cut -b10-34 | sort -u
  Angela Glinos            
  Peng Yi                  
  ordinary user            
  xiaoyu gao               
  J. T. C. Chiu            
  Lok Wilson