Unix Basic Commands III

In Vlsi Industries an engineer must be strong in the Digital Design, Analog Design and he/she should be strong in scripting language, shell commands. Few basic shell commnads which are widely used

• cat <file_name>——-display the information in a file without opening the file
• grep ————to search a word in that file
  syntax: grep [options] pattern [files]
  options Decsriptions
  –c: This prints only a count of the lines that match a pattern
  -h: Display the matched lines, but do not display the filenames
  -i: Display the matched lines, but do not display the filenames
  -l: Displays list of a filenames only
  -n: Display the matched lines and their line numbers
  -v: This prints out all the lines that do not matches the pattern
  -e exp: Specifies expression with this option. Can use multiple times
  -f file: Takes patterns from file, one per line
  -E: Treats pattern as an extended regular expression
  -w: Match whole word
  -o: Print only the matched parts of a matching line, with each such part on a separate output line
• mv –——– this is commad which is used to rename or move the file/directory
• cp –rf <soucre> <destination>————copy the file or directory to some other place
• cat filename > filename1 copies the information from filename to filename1
• pwd — gives full path of the present location
• wc –word count
• head –<no of lines to disply from top> <file_name> ——-gives the information of lines from top of the file
• tail -<no of lines to diplay from bottom> <file_name>——-gives the informations of lines from bottom of the file
• pipeline |  —–out put from the command on left of pipeline will be the input for the command on right of pipeline
  ex: ls | tee file.txt
  ls list the file/directory in the folder and then this will be the input to next command and the tee will  store the information in file.txt

Unix Basic Commands II

In Vlsi Industries an engineer must be strong in the Digital Design, Analog Design and he/she should be strong in scripting language, shell commands. Few basic shell commnads which are widely used

• To change the permission of a file or directory
  • chmod ——used for changing the  write/read/execute permissions

u,g,o individually represent the permission for user/owner ,group and others in same order 4 stands for read 2 stands for write 1 stands for execute 0 stands for no permissions

• chown——To change the owner and group of file  or directory
  • chown owner <file_name> –if only owner is given , that is user made owner of the given file and  file group is not changed
  • chown owner.group or owner:group <file_name> —  with this the user is made owner of the file   and the group of a file is changed

Unix Basic Commands I

In Vlsi Industries an engineer must be strong in the Digital Design, Analog Design and he/she should be strong in scripting language, shell commands. Few basic shell commnads which are widely used

• To get the information of commands
  • man <command_name>
    ex: man cd
  • <command_name> –ls
    ex: cd —ls
• To Change the Directory
  • cd <directory name/directory path>
    ex: cd directory name<or>directory path
    cd… ——– comes out of present directroy
• To list out the files or directory in present location
  •  ls gives the list of files or sub directories in present directory
  • ls -a gives the list of hidden files
• To link the file
  • ln <file_to_be_linked> instead of copying the file to we can link the file and thus save the space
• To create a directory
  • mkdir <directory_name>
    ex: mkdir vlsispace
  • mkdir –p  <directory>/<sub_directory>  creates a directory and then creates a sub_directory
    ex: mkdir -p /vlsi/space
• To create the files
  • touch  <file_name>  —— creates a empty file
  • vi<or>gvim<or>nedit <file_name> ——- this editors are used to create a file and the edit, save the files.
• To remove the files or Directories
  • rmdir  <directory_name>—— removes the directory
  • rm <file_name> —— removes the file
  • rm –rf  <file_name>or <directory_name>—– remove the directory or file