String library

The FortiADC OS supports only the Lua string library. All other libraries are disabled. The string library includes the following string-manipulation functions:

• string.byte(s, i)
• string.char(i1,i2…)
• string.dump(function)
• string.find(s, pattern)
• string.format
• string.gmatch
• string.gsub
• string.len
• string.lower
• string.match
• string.rep
• string.reverse
• string.sub
• string.upper
• string.starts_with
• string.ends_with

Note:

• If you want to use regular expression match, you can use string.match with Lua patterns.
• All relational operators >, <, >=, <=, ~=, == apply to strings. Especially, == can be used to test if one string equals to another string.
• string.find can be used to test whether one string contains another string.

For a tutorial on scripting with the Lua string library, see http://lua-users.org/wiki/StringLibraryTutorial.

For example: uri:starts_with (b), uri:ends_with (b)

Example 1:

a=12 

b=string.format(“%s, pi=%.4f”, a, 3.14) 

• {s:byte(1,-1)} 

Example 2:

str = “abc\1\2\0”
t={str:byte(1,-1)}
t is a table like an array to store the string.
t[1] is 97, t[2] is 98, t[3] is 99, t[4] is 1, t[5] is 2, t[6] is 0.
• {s:sub(1, 3)}
str="abcdefg"

Example 3:

str = “abc\1\2\0” 
t={str:byte(1,-1)} 
t is a table like an array to store the string. 
t[1] is 97, t[2] is 98, t[3] is 99, t[4] is 1, t[5] is 2, t[6] is 0. 

• {s:sub(1, 3)} 

str="abcdefg" 
test=str:sub(2,5) 
debug("return: %s \n", test) 
log("record a log") 

result:   “bcde”