Tech Talk given at the Rochester Institute of Technology's Society of Software Engineers about basic unix shell usage and productivity tips.

1. Text shells
Matt Mokary
and important productivity tips

2. TERMINAL-ogy
● Terminal window terminal window

3. TERMINAL-ogy
● Terminal window
● Terminal emulator
terminal emulator
terminal window

4. TERMINAL-ogy
● Terminal window
● Terminal emulator
terminal emulator
terminal window

5. TERMINAL-ogy
● Terminal window
● Terminal emulator
● Shell
terminal emulator
shell
terminal window

6. Modern Shells
● C Shell (csh)
● Bourne Again Shell (bash)
● Korn Shell (ksh)
● Z Shell (zsh)

7. Modern Shells
● C Shell (csh)
● Bourne Again Shell (bash)
● Korn Shell (ksh)
● Z Shell (zsh)

8. Basic usage
<program name> <program flags> [ arg1, arg2, … ]
$ ls

9. Basic usage
<program name> <program flags> [ arg1, arg2, … ]
$ ls
Applications Documents Library
Desktop Downloads Music
$

10. Basic usage
<program name> <program flags> [ arg1, arg2, … ]
$ ls -a

11. <program name> <program flags> [ arg1, arg2, … ]
$ ls -a
drwxr-xr-x 3 mattmokary staff 102 Feb 24 12:56 Applications
drwx------+ 5 mattmokary staff 170 Mar 20 17:06 Desktop
drwx------+ 11 mattmokary staff 374 Mar 20 12:03 Documents
drwx------+ 56 mattmokary staff 1904 Mar 20 14:54 Downloads
drwx------@ 49 mattmokary staff 1666 Feb 12 15:42 Library
drwx------+ 5 mattmokary staff 170 Feb 20 00:12 Music
$
Basic usage

12. <program name> <program flags> [ arg1, arg2, … ]
$ grep -n TODO MyProject.java
Basic usage

13. Basic usage
<program name> <program flags> [ arg1, arg2, … ]
$ grep -n TODO MyProject.java
23: // TODO is there an off-by-one error here?
131: // TODO document this function
340: // TODO make this more efficient
$

14. <program name> <program flags> [ arg1, arg2, … ]
$ gcc -o HelloWorld hello_world.c
Basic usage

15. <program name> <program flags> [ arg1, arg2, … ]
$ gcc -o HelloWorld hello_world.c
$
Basic usage

16. <program name> <program flags> [ arg1, arg2, … ]
$ gcc -o HelloWorld hello_world.c
$ ls
HelloWorld hello_world.c hello_world.o
$
Basic usage

17. Streams

18. Streams
● Standard Input (stdin)

19. Streams
● Standard Input (stdin)
● Standard Output (stdout)

20. Streams
● Standard Input (stdin)
● Standard Output (stdout)
● Standard Error (stderr)

21. Streams
$ cat test.txt

22. Streams
$ cat test.txt
This is a test file.
It has several lines,
none of which are very helpful.
This is the last line of the file.
$

23. Stream Redirection
● >

24. Stream Redirection
● > $ grep TODO MyProject.java

25. Stream Redirection
● > $ grep TODO MyProject.java
// TODO make this better
// TODO delete these
$

26. Stream Redirection
● > $ grep TODO MyProject.java > todo.txt

27. Stream Redirection
● > $ grep TODO MyProject.java > todo.txt
$

28. Stream Redirection
● > $ grep TODO MyProject.java > todo.txt
$ ls
MyProject.java todo.txt
$

29. Stream Redirection
● > $ grep TODO MyProject.java > todo.txt
$ ls
MyProject.java todo.txt
$ cat todo.txt
// TODO make this better
// TODO delete these
$

30. Stream Redirection
● >
>>
$ grep TODO MyProject.java > todo.txt
$ ls
MyProject.java todo.txt
$ cat todo.txt
// TODO make this better
// TODO delete these
$

31. Stream Redirection
● >
>>
● <

32. Stream Redirection
● >
>>
● <
$ grep TODO MyProject.java
// TODO make this better
// TODO delete these
$

33. Stream Redirection
● >
>>
● <
$ grep TODO < MyProject.java
// TODO make this better
// TODO delete these
$

34. Stream Redirection
● >
>>
● <
● |

35. Stream Redirection
● >
>>
● <
● |
$ grep TODO MyProject.java > todo.txt
$ wc -l todo.txt
2
$ rm todo.txt

36. Stream Redirection
● >
>>
● <
● |
$ grep TODO MyProject.java | wc -l

37. Stream Redirection
● >
>>
● <
● |
$ grep TODO MyProject.java | wc -l
2

38. Stream Redirection
● >
>>
● <
● |
$ grep TODO MyProject.java | wc -l
2
$ ruby get_hockey_tweets.rb
| grep -in sedin | grep -i henrik
| wc -l
173
$

39. Stream Redirection
● > redirect stdout to file stream
>> append stdout to file stream
● < redirect file stream to stdin
● | redirect stdout and stderr to stdin

40. Stream Redirection
● stdin (channel 0)
● stdout (channel 1)
● stderr (channel 2)

41. Stream Redirection
$ ./sqrt -1 2> errors.txt
No real solution.
$

42. Stream Redirection
$ ./sqrt -1 2> errors.txt
No real solution.
$ cat errors.txt
Argument is less than zero.
$

43. Stream Redirection
$ ./sqrt -1 2> errors.txt 1> /dev/null
$ cat errors.txt
Argument is less than zero.
$

44. Stream Redirection
$ ./postfix-solver 3 4 + 2>&1 > /dev/null
| grep syntax > syntax-errors.txt

45. Stream Redirection
$ ./postfix-solver 3 4 + 2>&1 > /dev/null
| grep syntax > syntax-errors.txt

46. Stream Redirection
$ ./postfix-solver 3 4 + 2>&1 > /dev/null
| grep syntax > syntax-errors.txt

47. Stream Redirection
$ ./postfix-solver 3 4 + 2>&1 > /dev/null
| grep syntax > syntax-errors.txt

48. Stream Redirection
$ ./postfix-solver 3 4 + 2>&1 > /dev/null
| grep syntax > syntax-errors.txt

49. Stream Redirection
$ ./postfix-solver 3 4 + 2>&1 > /dev/null
| grep syntax > syntax-errors.txt

50. Stream Redirection
$ ./postfix-solver 3 4 + 2>&1 > /dev/null
| grep syntax > syntax-errors.txt
$

51. Stream Redirection
$ ./postfix-solver 3 4 + 2>&1 > /dev/null
| grep syntax > syntax-errors.txt
$ ls
postfix-solver syntax-errors.txt
$

52. Stream Redirection
$ ./postfix-solver 3 4 + 2>&1 > /dev/null
| grep syntax > syntax-errors.txt
$ ls
postfix-solver syntax-errors.txt
$ cat syntax-errors.txt
$

53. Stream Redirection
● stdin 0
● stdout 1
● stderr 2
● 2> redirect stderr to file stream
● 2>&1 redirect stderr to current stdout
etc.

54. Every SE Ever:

55. Every SE Ever:
“I have no idea why this isn’t working.”

56. Every SE Ever:
“I have no idea why this isn’t working.”
“I have no idea why this is working.”

57. Every SE Ever:
“I have no idea why this isn’t working.”
“I have no idea why this is working.”
“How do I get out of vim?”

58. vim Modes
● Normal

59. vim Modes
● Normal
o insert a new line beneath the cursor, move to it,
and enter insert mode
$ move to the end of the line and remain in
normal mode
i enter insert mode at the cursor’s current
position
I move to the beginning of the line and enter
insert mode
dd cut the current line

60. vim Modes
● Normal
● Insert

61. vim Modes
● Normal
● Insert
● Command

62. vim Modes
● Normal
● Insert
● Command
:w write the buffer to the disk
:q quit vim; will stop you if the file has changed
since the last write
:q! quit vim and discard changes since last write
:wq write the buffer and quit vim
:x same as :wq
:<some number>
move the cursor to line <some number>

63. Typical vim Workflow

64. Typical vim Workflow
$ vim some-file.txt

65. Typical vim Workflow
$ vim some-file.txt
until you’ve made all the desired changes:
navigate through the file in normal mode

66. Typical vim Workflow
$ vim some-file.txt
until you’ve made all the desired changes:
navigate through the file in normal mode
bounce between normal and insert until part is fixed

67. Typical vim Workflow
$ vim some-file.txt
until you’ve made all the desired changes:
navigate through the file in normal mode
bounce between normal and insert until part is fixed
enter normal mode and write the file with “:w”

68. Typical vim Workflow
$ vim some-file.txt
until you’ve made all the desired changes:
navigate through the file in normal mode
bounce between normal and insert until part is fixed
enter normal mode and write the file with “:w”
enter normal mode

69. Typical vim Workflow
$ vim some-file.txt
until you’ve made all the desired changes:
navigate through the file in normal mode
bounce between normal and insert until part is fixed
enter normal mode and write the file with “:w”
enter normal mode
write the file and quit vim with “:wq” or “:x”

70. vim Visual Mode

71. vim Visual Mode
x cut the highlighted text and save it to vim’s
clipboard
y copy the highlighted text and save it to vim’s
clipboard
p (in normal mode)
paste the text in vim’s clipboard into the buffer
after the cursor
P (in normal mode)
paste the text in vim’s clipboard into the buffer
before the cursor

72. tmux

73. tmux
$ Shell

74. tmux
$ tmux new -s Crypto
$
Shell
tmux session
“Crypto”

75. tmux
$ tmux new -s Crypto
$ tmux ls
Crypto: 1 windows … (attached)
$
Shell
tmux session
“Crypto”

76. tmux
$ tmux new -s Crypto
$ tmux ls
Crypto: 1 windows … (attached)
$ tmux detach
$
Shell
tmux session
“Crypto”

77. tmux
$ tmux new -s Crypto
$ tmux ls
Crypto: 1 windows … (attached)
$ tmux detach
$ tmux new -s Grading
$
Shell
tmux session
“Crypto”
tmux session
“Grading”

78. tmux
$ tmux new -s Crypto
$ tmux ls
Crypto: 1 windows … (attached)
$ tmux detach
$ tmux new -s Grading
$ tmux kill-session -t Crypto
$
Shell
tmux session
“Grading”

79. tmux
$ tmux new -s Crypto
$ tmux ls
Crypto: 1 windows … (attached)
$ tmux detach
$ tmux new -s Grading
$ tmux kill-session -t Crypto
$ tmux detach
$
Shell
tmux session
“Grading”

80. tmux Session

81. tmux Session
CTRL+b % vertical split

82. tmux Session
CTRL+b % vertical split
CTRL+b “ horizontal
split

83. tmux Session
CTRL+b % vertical split
CTRL+b “ horizontal
split
CTRL+b x y kill pane

84. tmux Session
CTRL+b % vertical split
CTRL+b “ horizontal
split
CTRL+b x y kill pane
CTRL+b arrows
navigate panes

85. My Personal Setup

86. Thanks!