CS6 PracticalSystemSkillsFall 9 editionLeonhard Spiegel erglspiegel@ s. rown.edu

. Re ap

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. Re ap

/

⇒ /

⇒ . .. ~

cd

ls

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. Re ap uiz

/usr/local/bin

cd ..

cd ./../..

cd

cd ~

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. Re ap uiz

/usr/local/bin

cd .. /usr/local

cd ./../.. /usr

cd HOME directory

cd ~ HOME directory

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. Re ap uiz

ls Documents

ls

ls -a

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Documents

mail .backups

2018 2019 .backupdb

cwd

. Re ap uiz

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Documents

mail .backups

2018 2019 .backupdb

cwdls Documents

ls: Documents: No such file or directory

ls

mail

ls -a

. .. mail .backups

FilesCS6 Pra ti al System SkillsFall 9Leonhard Spiegel erg lspiegel@ s. rown.edu

. C eatin and deletin files

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touch file mkdir directory_name

rm file rmdir directory_name

. Wo kin ith di e to ies

-p

mkdir -p folder/subfolder/subsubfolder

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. Deletin files and di e to ies

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. Deletin files

-r

rm -r folder/

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. Deletin files in a t ee

-r

-i

Example:

rm -ri folder/

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. Deletin files in a t ee

-r

-f

Example:

rm -rf folder/

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Ba k to the te minal...

. O anizin files

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mv src ... destmove file from src location to dest location⇒ can be used to rename a file

cp src ... destcopy file from src location to dest location

. Cop in di e to ies

cp -R src dest

/ cp

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. Cop in di e to ies

Examples: cp -R folder copy

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cwd cwd

. Cop in di e to ies

Examples: cp -R folder/ copy

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cwd cwd

. Cop in di e to ies

Examples: cp -R folder/ .

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cwd cwd

. Cop in di e to ies

Examples: cp -R folder/ dest

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cwd cwd

. Cop in di e to ies

Examples: cp -R folder dest

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cwd cwd

. Mo in di e to ies

mv folder dest

mv folder/ dest

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cwd cwd

. Renamin files/di e to ies

⇒ dest mv

⇒ -n -i

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cwd

mv folder/a.txt folder/file.txt

cwd

. Renamin files/di e to ies

⇒

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cwd

mv folder dir

cwd

Ho to m o p a su set o files?

. UNIX ild a ds

⇒

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. UNIX ild a ds

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*

?

[...]

[a-z]

[0-9]

[a-zA-Z]

[a-zA-Z0-9]

[!...]

[!123]

Hint: escape [, *, ? using a backslash, e.g. * ⇒ \*

. UNIX ild a ds - e ample

⇒

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/*folder/file?.txt

/folder/file1.txt/subfolder/filea.txt/subsubfolder/fileB.txt

folder/file.txtfolder/file1.txt/subfolder/a.txt/folder/subfolder/file1.txt

. UNIX ild a ds

mv *.jpg images/

mv *?.jpg images/

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. UNIX ild a ds

mv *.jpg images/

mv *?.jpg images/

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. UNIX ild a ds

cp [0-9][0-9]_*.pdf slides/

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. UNIX ild a ds

⇒

⇒

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mv {*.png,*.jpg} images/

. B a e e pansion

{...}

{*.png,*.jpg}⇒ *.png *.jpg

Example:

mv {*.png,*.jpg} images/

⇒ mv *.png *.jpg images/

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. B a e e pansion

Shorter version:

mv *.{png,jpg} images/

⇒ mv *.png *.jpg images/

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. B a e e pansion

Example:

ls {lecture,slide*}_??.{pdf,dvi}

⇒ ls lecture_??.pdf lecture_??.dvi slide*_??.pdf slide*_??.dvi

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. B a e e pansion

⇒

Examples:

ls {a,b{c,d}}.txt

⇒ ls a.txt b{c,d}.txt

⇒ ls a.txt bc.txt bd.txt

ls {a,{b,c}}.txt

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. B a e e pansion

cp file{,.backup}

⇒ cp file file.backup

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. UNIX ild a ds

cp *.*{,.backup}

⇒ cp *.* *.*.backup

⇒

⇒

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Ho an e a ess the ontents o a file?

. File t pes

⇒

⇒

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. Te t files

cat file …

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. Te t files - ASCII

⇒

⇒

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. Te t files - ISO/IEC -

⇒

⇒

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. Te t files - ASCII and UTF- en odin

⇒

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. Te t files - UTF- en odin

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number of bytes Byte 1 Byte 2 Byte 3 Byte 4

1 ASCII chars 0xxxxxxx

2Latin, Greek, Cyrillic, Coptic, Armenian, Hebrew, Arabic,

Syriac, Thaana, ...110xxxxx 10xxxxxx

3 Chinese, Japanese, Korean, …. 1110xxxx 10xxxxxx 10xxxxxx

4 Math symbols, Emojis 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx

. Editin te t files

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⇒

. Bina files

⇒

hexdump file

⇒

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. he dump

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hexdump penguin.jpg

0000000 ff d8 ff e1 12 d4 45 78 69 66 00 00 4d 4d 00 2a0000010 00 00 00 08 00 0c 01 00 00 03 00 00 00 01 08 000000020 00 00 01 01 00 03 00 00 00 01 0c 00 00 00 01 020000030 00 03 00 00 00 03 00 00 00 9e 01 06 00 03 00 000000040 00 01 00 02 00 00 01 12 00 03 00 00 00 01 00 010000050 00 00 01 15 00 03 00 00 00 01 00 03 00 00 01 1a0000060 00 05 00 00 00 01 00 00 00 a4 01 1b 00 05 00 000000070 00 01 00 00 00 ac 01 28 00 03 00 00 00 01 00 020000080 00 00 01 31 00 02 00 00 00 24 00 00 00 b4 01 320000090 00 02 00 00 00 14 00 00 00 d8 87 69 00 04 00 00...

. he dump s. at

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cat file.txt

Tux loves CS6

hexdump -c file.txt

0000000 T u x l o v e s C S 6 \n000000e

hexdump file.txt

0000000 54 75 78 20 6c 6f 76 65 73 20 43 53 36 0a000000e

⇒

. file

file file

⇒

⇒

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Example:

file penguin.jpg

penguin.jpg: JPEG image data, Exif standard: [TIFF image data, big-endian, direntries=12, height=3072, bps=0, PhotometricIntepretation=RGB, orientation=upper-left, width=2048], progressive, precision 8, 512x513, frames 3

. Uni o a ula so a

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cd

ls

touch

rm

mkdir

rmdir

mv

cp

cat

hexdump

file

Use s and Pe missions

CS6 Pra ti al System SkillsFall 9Leonhard Spiegel erg lspiegel@ s. rown.edu

. Pe missions

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. Pe missions

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. Pe missions o di e to ies

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. Use s and pe missions

⇒

⇒

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. Use s and pe missions

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⇒

. ls lon o mat

ls -l

total 88

-rw-r--r-- 1 sealion friends 14 9 Sep 8:01 file.txt

-rw-r--r-- 1 sealion friends 40390 9 Sep 9:00 penguin.jpg

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owner and user are usually the same! Terms are used interchangeably here often.

. Pe missions

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- rw- r-- --x

-

d

l

p

s

b

c

. Settin pe missions - hmod

chmod mode file …

⇒

⇒

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. hmod - s m oli mode

chmod u=rw,g=rx,o= file.txt

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. hmod - nume i mode

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0 000 ---

1 001 --x

2 010 -w-

3 011 -wx

4 100 r--

5 101 r-x

6 110 rw-

7 111 rwx

chmod u=rw,g=rx,o= file.txt ⇒ chmod 650 file.txt

Mo e details ne t le tu e!

P e ie ne t le tu e

⇒

⇒

⇒

⇒

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P e ie HW :

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P e ie La :

⇒

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End of lecture.Next class: Thu, pm- :20pm @ CIT 77