CS155: Unix Commands III Lecture 8

1
CS155 Unix Commands IIILecture 8
2
Review

• Use gt to redirect stderr and stdout
• Use Ctrl-Z, bg, fg, jobs, and to run multiple
  jobs at the same time.
• C-Shell keeps a history of commands which you can
  use to speed up your work.

3
Time Commands

• date Display the current date and time
• cal display a simple calendar
• -3 Display previous, current, and next month
• -y Display a calendar for the year

gt date Fri Feb 3 100217 MST 2006 gt cal
February 2006 Su Mo Tu We Th Fr Sa 1 2
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
18 19 20 21 22 23 24 25 26 27 28
3
4
System Commands

• uptime information on system load, number of
  users, and uptime
• who list of users currently logged in
• w combination of uptime and who

gt w 100841 up 1 day, 1841, 5 users, load
average 0.00, 0.01, 0.02 USER TTY FROM
LOGIN_at_ IDLE JCPU PCPU
WHAT boese 0 - Thu12
?xdm? 1250 0.02s /usr/bin/wmaker boese
pts/0 - Thu13 1525 0.14s
0.00s /usr/bin/perl / boese pts/2 -
1005 240 0.01s 0.01s
/usr/local/bin/ boese pts/1
18vpn220.vpn.col 1002 0.00s 0.04s 0.00s w
5
Finding Things in the Filesystem

• When you execute a command or program, Unix
  search a list of paths for the executable.
• which give the full path of an executable
• whereis search all common executable
  directories for binaries, man pages, source files.

6
find

• find searches the file system for a file or
  files based name or other features.
• Usage find path expression
• find searches recursively from path down looking
  for files that match expression.

7
find Common Expressions

• -name pattern search for files with name
  matching pattern. Pattern uses wildcard symbols.
• find . name html
• Search for directories named html
• find . -name html or html
• Search for files and directories ending with html

gt find -name cs155 /s/chopin/k/fac/boese/mai
l/cs155 /s/chopin/k/fac/boese/school/cs155 /s/chop
in/k/fac/boese/school/BLAHcs155YO /s/chopin/k/fac/
boese/school/cs155_logins
8
find Common Expressions

• -user uname file is owned by user
• Time-based
• -amin -n file access up to n minutes ago
• -ctime n file status last changed up to n24
  hrs ago
• -mtime n file was last modified up to n24

gt find -name cs155 /s/chopin/k/fac/boese/mai
l/cs155 /s/chopin/k/fac/boese/school/cs155 /s/chop
in/k/fac/boese/school/cs155/cs155 /s/chopin/k/fac/
boese/school/cs155/cs155_logins
9
find Actions

• We can specify actions for find to perform on
  each file it finds.
• -delete delete found files
• -ls give full listing of files
• -exec command run command on files

• gt find . amin -5 ls
• 883353 4 drwx------ 5 boese fac 4096 Feb
  1 1150 .
• 2714705 12 -rw------- 1 boese fac 11534 Jan
  17 1426 ./cs155
• 3467028 4 drwx------ 4 boese fac 4096 Jan
  28 1037 ./hw2_files
• find . name .bak exec mv old \
• Search for a string in a selection of files
  (executing grep)
• find . -exec grep Boese" '' \ -print

10
find exec

• The exec action can be very handy.
• Everything after exec is considered part of the
  command to execute until a is encountered.
  The must be escaped by using \ because it
  is a special character in the shell.
• All occurrences of are replaced by the
  full path to the found file.

11
Miscellaneous Commands

• uname print system information
• -a print all information
• su - switch user (login in as different user)
• whoami get current user name
• touch change access and modification times of
  files
• bc Basic Calculator

12
Miscellaneous Commands 2

• ispell spell check a file
• ping check whether IP Address is accessible

13
Printing in Unix
Network
guitar.cs.colostate.edu
sitar.cs.colostate.edu
14
Print Commands

• lpr send file to printer without formatting
• -Pprinter sent to printer
• lpr Pguitar my_file
• lpq list the printer queue
• printers print jobs on first in first out basis
• lpq gives order and status of print jobs
• -Pprinter specify the printer
• lprm remove print job
• lprm Pguitar 452
• lprm Pguitar -

15
Print Commands
gt lpr Pguitar my_file gt lpr Pguitar my_file2 gt
lpq -Pguitar guitar is ready and printing Rank
Owner Job File(s) Total
Size active boese 1016 my_file
1944576 bytes 1st xhua 1021 (stdin)
12432 bytes 2nd boese 1028
my_file2 134144 bytes gt lprm
Pguitar 1028 gt lpq Pguitar guitar is ready and
printing Rank Owner Job File(s)
Total Size active xhua 1021 (stdin)
12432 bytes
16
Printing

• enscriptenscript -2rGjdcymbal
• 2 2 columns
• r rotate (landscape/portrait)
• G fancy header (e.g. date, filename)
• j print borders around columns
• d printerName destination