Shell Scripting Tutorial for Beginners 5 - If Statement ( If then , If then else, If elif else)

Shell Scripting Tutorial for Beginners 5 - If Statement ( If then , If then else, If elif else) Conditionals let us decide whether to perform an action or not, this decision is taken by evaluating an expression. Expressions An expression can be: String comparison, Numeric comparison, File operators and Logical operators and it is represented by [expression]: String Comparisons: --------------------------------- = compare if two strings are equal != compare if two strings are not equal -n evaluate if string length is greater than zero -z evaluate if string length is equal to zero Examples: [ s1 = s2 ] (true if s1 same as s2, else false) [ s1 != s2 ] (true if s1 not same as s2, else false) [ s1 ] (true if s1 is not empty, else false) [ -n s1 ] (true if s1 has a length greater then 0, else false) [ -z s2 ] (true if s2 has a length of 0, otherwise false) Number Comparisons: ------------------------------------ -eq compare if two numbers are equal -ge compare if one number is greater than or equal to a number -le compare if one number is less than or equal to a number -ne compare if two numbers are not equal -gt compare if one number is greater than another number -lt compare if one number is less than another number Examples: [ n1 -eq n2 ] (true if n1 same as n2, else false) [ n1 -ge n2 ] (true if n1greater then or equal to n2, else false) [ n1 -le n2 ] (true if n1 less then or equal to n2, else false) [ n1 -ne n2 ] (true if n1 is not same as n2, else false) [ n1 -gt n2 ] (true if n1 greater then n2, else false) [ n1 -lt n2 ] (true if n1 less then n2, else false) ===== TAGS ===== bourne shell and programming,bash scripting,unix,tutorials,learning,operating,system,os,beginners,basics,system calls,korn,bourne,shell,programming,utilities,file system,directories,memory management,special variables,vi editor,processes,what is shell?,using shell variables,pass arguments,scripting tutorial,bash tutorial,bash scripting tutorial,bash,scripting,if,elif,else,if statements,case ===================================== LIKE || COMMENT || SHARE || SUBSCRIBE!!!!!! ===================================== If There is Anything You Want Me to Cover Then Do Let Me Know. This Video is For Educational Purposes Only! I'm Not Responsible For Your Actions!