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