03-Unix.pdf

Transcript

1. ICS 212 Program Structure William McDaniel Albritton M.S.
2. Memory Allocation  SSH Software  Unix Commands  emacs Commands
4. SSH Software
5. SSH Software  SSH stands for Secure SHell  It is an encrypted version of Telnet, which provides a command line interface for a remote host (a computer far far away)  Since Telnet uses plain text, anyone listening to your Internet connection can get your username and password
6. SSH Software  SSH prevents hackers from monitoring your network messages by encrypting the information  Other advantages of SSH include the ability to make multiple windows quickly and easily
7. SSH Software  You can download SSH (and other software) from the UH Information Technology Services (ITS) Supported Software page: http://www.hawaii.edu/askus/778
8. SSH Software  After you download the software, you should have two icons  Yellow icon (SSH Secure File Transfer Client): to transfer files to UHUNIX account  Gray icon (SSH Secure Shell Client): command line interface to access the UHUNIX operating system
9. SSH Software  Clicking either icon will bring up this window  Click the “Quick Connect”button
10. SSH Software  To log in, use
11. SSH Software  Enter your UH password
12. SSH Software  Click “Yes”
13. SSH Software  Your computer is displayed on the left window
14. SSH Software  Your UHUNIX account is displayed on the right window
15. SSH Software  To see new files in SSH, you may need to press the Refresh button (two arrows) at the top of the window
16. SSH Software  Move files from your computer to UHUNIX account by dragging the file from left to right window (and vice versa)
17. SSH Settings  Changing the settings for the command line interface (Click Edit, then Settings)  Keyboard  Font  Color
18. SSH Settings  Before closing SSH, save the profile  Click File, then Save Settings  Click File, then Save Layout
19. SSH Settings Hands On
21. Unix Commands
22. Command Line Interface  Click on the gray icon at the top of the SSH Secure File Transfer window to open the command line interface
23. Command Line Interface  On the right is a screen shot of the command line interface
24. The Format  Bullets will be used for theory Computer view in dark gray background
25. Unix Commands  tcsh  Running the TC Shell (TENEX C Shell) will enable these features: backspace, command line completion, and repeat a command uhunix2:/home/27/walbritt% tcsh
26. Unix Commands  tcsh  For command line completion, pressing the tab key will complete a file name  To repeat a command, press the up and down arrow keys to scroll through a history of the commands, then press the enter key to execute the command
27. Unix Commands  *  Many commands allow wild card characters in the file names  An * (asterisk) stands for any string of 0 or more characters  For example, *.c means all files that end with .c
28. Unix Commands  ls *.c uhunix2:/home/27/walbritt% ls *.c a.c a4.c final.c test.c a1.c a5.c program.c a12.c a8.c solution08.c a2.c aloha.c temp.c
29. Unix Commands  ls program* uhunix2:/home/27/walbritt% ls program* program program.c program.cpp program.c~ program.o
30. Unix Commands  ?  Many commands allow wild card characters in the file names  A ? (question mark) stands for any single character  For example, ?.c means all files that end with .c with one character names
31. Unix Commands  ls ?.c  ls program.? uhunix2:/home/27/walbritt% ls ?.c a.c uhunix2:/home/27/walbritt% ls program.? program.c program.o
32. Unix Commands  cd dirname  Change directory  For example, "cd ics212" will change to the ics212 directory  "cd .." will move one directory higher
33. Unix Commands  cd ics212  cd .. uhunix2:/home/27/walbritt% cd ics212 uhunix2:/home/27/walbritt/ics212% uhunix2:/home/27/walbritt/ics212% cd .. uhunix2:/home/27/walbritt%
34. Unix Commands  cat filename  more filename  less filename  Different commands to display a file  For example, "cat aloha.c" will display the file aloha.c on your screen
35. Unix Commands  cat aloha.c uhunix2:/home/27/walbritt% cat aloha.c /*Will output aloha!*/ #include <stdio.h> int main(void){ printf("Aloha!\n"); return 0; }
36. Unix Commands  pwd  Print working directory (your current directory)  Note: to save space, we will use only the % (percent sign) as the UNIX prompt in the slides from now on % pwd walbritt@uhx01:/home/27/walbritt/public_html/ic s212/examples
37. Unix Commands  man command  Display on-line manual for command  For example, "man ls" will display a short manual on the "ls" command % man ls
38. Unix Commands  For more details on UNIX commands, see the “UNIX Commands” link on the class webpage
39. Unix Commands Hands On
41. Unix Editor
42. emacs  A Unix editor
43. emacs Commands  See the “Emacs Commands” link on the class webpage for a list of basic emacs commands
44. emacs Commands  To run emacs  emacs file.c
45. emacs Commands  Type the code in the program file  To move around, use the arrows
46. emacs Commands & SSH  SSH has copy and paste, but it works a little differently from usual windows  You can select something with your mouse and copy (but not cut) the selected text  Then when you paste, the text is inserted where the cursor is, not where the mouse pointer or selection is
47. emacs Commands  To save without exiting  To save and exit X Ctrl S Ctrl X Ctrl C Ctrl
48. emacs Commands  Delete the character at the cursor  Delete the character preceding the cursor  Delete from the cursor to the end of the line D Ctrl K Ctrl
49. emacs Commands  Search for a word  It does an "incremental search." For example, if you are looking for "hello", you type h and it looks for the first h. Then you type e and it looks for "he".  Type Ctrl-s again, and it will look for the next occurrence of the word S Ctrl
50. Multiple Windows  With SSH, you can have any number of windows  I recommend that you start by opening one window in which you run a program and another window for editing  Edit a program in the edit window  Then save it (use Ctrl-x Ctrl-s), and then compile it and run it in the other window
51. Customize your emacs  There is a file in your main directory called “.emacs” which you can use to customize your emacs  For example, to enable the backspace key, disable tabs, and set the indention to 2 spaces, see detailed code at the bottom of the webpage “Emacs Commands” (see the link on the class webpage)
52. emacs Hands On
53. Output Redirection in Unix  Usually, output is displayed on the terminal  However, we can change where standard output is stored by using a command, followed by a greater- than-sign (>), and then a file name  The output will be stored in the file!  Syntax: command > file.txt
54. Output Redirection in Unix  Stores the contents of the “ls” command in file1.txt  Stores contents of “history” command in file2.txt % ls > file1.txt % history> file2.txt
55. Memory Management  SSH  Unix Command  emacs Commands  Check the class website for assignment  Post any question to the discussion board