1.匹配字符串中的数字、字母和下划线

str = "hello_+asdf2312+887441a+asdf"

table = {}

string.gsub(str, "([%w_]+)", 
function(w)

table.insert(table, w)
end)

end)

2.替换字符串中的指定字符

str = "hello,john"

s = string.gsub(str, "john", "james")

s ==>"hello,james"

3.判断字符串中是否有目标字串

str = "hello,john"

start, end = string.find(str, "hello")

start ==>1

end ==>5

4.从文件的绝对路径中获取到文件名

fn_flag = string.find(filename, "\\")
if fn_flag then

dest_filename = string.match(filename, ".+\\([^\\]*%.%w+)$")

end

fn_flag = string.find(filename, "/")
if fn_flag then

dest_filename = string.match(filename, ".+/([^/]*%.%w+)$")

end