syntax of if in Ksh

[harikrishna]

hi,
plz let me know the syntax of if in Ksh with or operator.is sytax for integer comparisions and string comparisions.
THANKS

[G. Vrijhoeven]

Hi,

Check man ksh:
if then else elif fi

Gideon

[Mark Grant]

Basic syntax

if expression
then
code
fi

comparisons are normally done with "test" which is also called "[" so

if [ $a > "abc" ]
then
echo "$a is alphabetically larger that abc"
fi

or for numerics

if [ $a -gt 10 ]

Alternatively, miss out the if altogether and rely on the && (and) and || (or) operators as in

[ $a -gt 10 ] && {
echo "$a is greater than ten"
}

[Mark Greene_1]

use the ksh built-in test syntax of [[ ]]

strings are compared vi > < and =

integers use -gt -lt -eq -ge -le

so you have tests like this:

if [[ "$String1" > "$String2" ]]; then

and

if [[ $Int1" -gt "$Int2" ]]; then

mark

[curt larson_1]

for string comparisions use [[....]]

string == Pattern
true if string matches pattern Pattern.
Quote Pattern to treate it as a string.
= is obsolete and may be replaced in the future. Use == rather then =.

string != Pattern
string does not match pattern Pattern

string1 < string2
string1 comes before string2 in the collation order defined by the current locale

string1 > string2
string1 comes after string2 in the collation order defined by the current locale

for arithmetic expressions use ((....))

expression < expression
less then

expression > expression
greater then

expression <= expression
less then or equal to

expression >= expression
greater then or equal to

expression == expression
equal to

expression != expression
not equal to

the value of an expression with a comparison operator or a logical operator is 1 is non-zero (true), or 0 (false) otherwise.

[Jim Butler]

http://www.bolthole.com/solaris/ksh-builtins.html