Bash is a Unix shell written by Brian Fox for the GNU Project as a free software replacement for the Bourne shell. Released in 1989, it has been distributed widely as the default shell on Linux and Mac OS X. The document then explores various topics in Bash scripting including variables, conditional statements and loops, functions, string manipulations, I/O redirection, and special commands like grep, find, awk, sed, and alias.
3. ? Bash is a Unix shell written by Brian Fox for the GNU Project as a
free software replacement for the Bourne shell .
? Released in 1989,it has been distributed widely as the shell for
the GNU operating system and as a default shell on Linux and
Mac OS X.
40. a.Grep
? Is used to search a characters chain within a file
? -v displays the lines that do not contain the string
? -c count the number of lines containing the string
? -n each line containing the string is numbered
? -x the line that exactly matches the string
? -l displays the names of files that contain the string
42. b.Find
? Is used to fined files based on specific criteria.
? Syntax: find <folder> <search criteria>
? -name search by name
? -perm search by access rihghts on file,
? -user search by file¡¯s owner,
? -group search by file¡¯s group,
46. c.Awk
? Is used to print specific lines and columns from a file, with
conditions.
? Syntax : awk '{print $NF}' file
49. d.Sed
? The SED UNIX Command in Linux enables you to work with the
text inside your files and can be used to perform different
functions to it.
? Syntax :
52. e.Alias
? Is used to enable a replacement of a command by another
string
? Syntax : alias myalias=¡°command_name¡±