Utilities (ch 3) Outline. Special Characters. Special Characters. Special Characters. Special Characters

Transcription

1 Utilities (ch 3) IT244 - Introduction to Linux / Unix Instructor: Bo Sheng Outline Special characters in Linux/Unix Basic utilities Display / copy / delete files Sort / search in files Compare files, obtain file information Pipe 1 2 List on Pg 50 Avoid unnecessary use Treat them differently Examples echo hello world > hello echo hello * world > hello echo hello ~ world > hello 3 4 Use quote or echo hello * world > hello echo hello ** world > hello echo hello ~ world > hello echo hello ~~ world > hello Use \ echo hello \* world > hello echo hello \*\* world > hello Invisible/control characters CTRL-C, CTRL-U, Use CTRL-V 5 6 1

2 Special characters in file names Create a file hello world echo HELLO WORLD > hello world List on Pg 50 Avoid unnecessary use Treat them differently The safe way is to use or echo HELLO WORLD > hello world echo HELLO WORLD > hello\ world 7 8 Preparation cd /home/your username/it244 pwd (make sure of the working directory) /home/shengbo/it244/prep List files l Size File name 9 10 Display files cat linux more linux less linux Display files head linux tail linux head 1 linux tail 5 linux

3 Copy files cp source-file destination-file cp linux linux.copy cp /home/shengbo/it244/welcome welcome more welcome Copy files Overwriting cp hello linux cat linux -i option cp i hello linux cp linux.copy linux (restore file linux ) Rename files ( mv ) mv linux.copy mylinux Overwriting cat mylinux cat hello mv mylinux hello cat hello -i option Delete files ( rm ) rm hello Safe way of deleting ( -i option) echo hello world > hello rm i hello Display a file in order ( sort ) sort linux sort days sort r months sort days months Remove duplicate lines cat dups uniq dups Identify file types ( file ) file linux file hello file /home/shengbo/it244/exetest file /home/shengbo/it244/umb.jpg

4 Word counter ( wc ) wc linux lines words chars Search a string in files grep Linux linux grep J months grep n months days wc l months wc w hello Pipe (communication between commands) command1 command 2 sort months head -4 wc w grep color /home more bzip2 bzip2 v linux l (compare the file sizes) bunzip2 linux.bz2 -k keeps the original file bzip2 vk linux bzcat linux.bz gzip (GNU zip) gzip, gunzip, zcat gzip linux -l zcat linux.gz Try multiple files gzip days months linux gunzip days.gz months.gz linux.gz bzip2 bunzip2 gunzip linux.gz

5 tar is for archiving not compressing tar cvf all.tar days months -c:create, -v:verbose, -f:specify filename tar is for archiving not compressing Compress.tar files using bzip2 and gzip.tar.gz,.tgz,.tar.bz2,.tbz l (compare file sizes) tar tf all.tar (list files) tar xvf all.tar (extract files) tar cvf all.tar months days linux gzip v all.tar Decompress tar.gz files gunzip all.tar.gz l tar xvf all.tar gunzip c all.tar.gz tar xv tar zxvf all.tar.gz Record shell display ( script ) script / exit script ls cat months exit cat typescript -a option for appending Locating Utilities/Commands which and whereis Multiple copies of utilities which checks search path and display the first result which tar which wc whereis checks standard directories whereis tar whereis wc Locating Utilities/Commands which and whereis Built-in utilities whereis echo which echo type echo type cd

6 date date User and System Info Format the display date + %A %B %d who ( list users on the system) who who am i User and System Info finger ( list users on the system ) finger your username finger it244 finger sheng cd /home/your username echo *** >.plan echo *** >.project finger your username w User and System Info Comparison table (Pg 73) Summary Special characters Basic utilities, cat, more, less, head, tail cp, mv, rm (overwrite, -i ) sort, uniq, file, wc, grep (pipe) Compress/Archive files bzip2, gzip, tar Shell record (script / exit) User/System info date, which/whereis, locate, type who, finger, w