directory and file control

1
Lecture 7

• directory and file control
• your programming environment
• loops

2
Recording your screen interactions

• fitzpatricke_at_baboon script
• Script started, file is typescript
• sh-3.00 cd lex.growth
• sh-3.00 ./lexy.loop alice30.txt
• sh-3.00 more stats.loop
• xaa.out 1893
• xab.out 761
• xac.out 539
• xad.out 407
• sh-3.00 exit
• exit
• Script done, file is typescript

3
The file typescript

• Script started on Mon Oct 31 141317 2005
• sh-3.00 cd lex.growth
• sh-3.00 ./lexy.loop alice30.txt
• rm cannot remove x' No such file or directory
• rm cannot remove .out' No such file or
  directory
• sh-3.00 more stats.loop
• xaa.out 1893
• xab.out 761
• xac.out 539
• xad.out 407
• sh-3.00 exit
• exit
• Script done on Mon Oct 31 141346 2005
• Read 14 lines
• G Get Help O WriteOut R Read File Y Prev Pg
  K Cut Text C Cur Pos
• X Exit J Justify W Where is V Next Pg
  U UnCut TextT To Spell

4
Your Programming Environment- Dotfiles -

• ls -a show files that determine your
  programming environment at login
• . .bash_profile
• .. .bashrc
• .Xdefaults .screenrc
• .bash_history
• .bash_logout

5
The alias

• Aliasing allows you to call one thing another
  thing
• example
• alias guten'cd /home/data/text.data/gutenberg'

6
Changing rm in your .bash_profile

• cd
• ls -a
• cp .bash_profile .bash_profile.bak
• pico .bash_profile
• alias rm rm -i
• w
• q
• . .bash_profile

7
Directory File Control(System Utilities)

• cd change directory
• pwd print working directory
• mkdir dn make a directory, call it dn
• ls -l -t list long list list by time
• cp fn1 fn2 copy fn1 to fn2
• chmod ow fn allow others to write to fn
• history show all past commands

8
echo

• echoes its arguments on the screen
• echo Hello world
• Hello world
• handy for checking shorthand characters
• echo chap
• chap1 chap2 chap3
• echo chap1-2
• chap1 chap2

9
Environment variables

• .bash_profile
• contains variables that set up your environment
• HOME
• stores the pathname of your home directory
• PATH
• stores the list of directories to search for
  programs

10
PATH

• /usr/kerberos/bin baboon sys admin progs
• /usr/local/bin nothing there!
• /bin progs you will recognize
• /usr/bin machine stuff
• /usr/X11R6/bin X windows stuff
• /home/your_username/bin Directory for your
  programs

11
Variables you know (and love?)

• HOME
• PATH
• 0, 1, 2
• Moral variables begin with a dollar sign

12
Putting a loop in a shell script

• a loop is used to execute the same command(s)
  repeatedly
• Syntax of a for loop
• for variable in list
• do
• command(s) including variable
• done

13
Sample looping over a list

• !/bin/bash
• riders
• generate a childs nursery rhyme
• for people in gentleman lady farmer
• do
• echo This is the way the people rides
• done

14
Output of sample loop

• riders
• This is the way the gentleman rides
• This is the way the lady rides
• This is the way the farmer rides

15
Looping over a list of files

• ls /home/lucent/wangx/ubdb/.in
• TP001.in TP049.in
• TP002.in
• TP003.in
• TP004.in
• TP005.in
• TP006.in
• TP007.in

16
Looping over a list of files (2)

• !/bin/bash
• for file in /home/lucent/wangx/ubdb/.in
• do
• tail file gtgt tail.in
• done

17
Output of loop over files

• problem
• pcl 3.727632
• p 3.757441
• r 3.8198171
• "_o 3.934128
• bcl 4.0380421
• b 4.0380421
• l 4.0597081
• 4.1383228
• m 4.178987
• ,
• 4.5711851

• children
• Ccl 4.6082158
• C 4.7256999
• "_i 4.827867
• l 4.8504529
• dcl 4.8852291
• d 4.9105291
• r 4.950274
• 5.0135241
• n 5.0482998
• ,
• 5.5064631