func show_strlen(s string) int {
sl := 0
rs := []rune(s)
for _, r := range rs {
rint := int(r)
if rint < 128 {
sl++
} else {
sl += 2
}
}
return sl
}
#倒序截取
func show_substr_reverse(s string, l int) string {
if len(s) <= l {
return s
}
ss, sl, rl, rs := "", 0, 0, []rune(s)
for i:=len(rs)-1;i>=0;i-- {
r := rs[i]
rint := int(r)
if rint < 128 {
rl = 1
} else {
rl = 2
}
if sl + rl > l {
break
}
sl += rl
ss = string(r) + ss
}
return ss
}
#正序截取
func show_substr(s string, l int) string {
if len(s) <= l {
return s
}
ss, sl, rl, rs := "", 0, 0, []rune(s)
for _, r := range rs {
rint := int(r)
if rint < 128 {
rl = 1
} else {
rl = 2
}
if sl + rl > l {
break
}
sl += rl
ss += string(r)
}
return ss
}