mirror of
https://github.com/k3s-io/k3s.git
synced 2024-06-07 19:41:36 +00:00
363 lines
10 KiB
Go
363 lines
10 KiB
Go
// Copyright 2012 Neal van Veen. All rights reserved.
|
|
// Usage of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file.
|
|
|
|
package gotty
|
|
|
|
import (
|
|
"bytes"
|
|
"errors"
|
|
"fmt"
|
|
"regexp"
|
|
"strconv"
|
|
"strings"
|
|
)
|
|
|
|
var exp = [...]string{
|
|
"%%",
|
|
"%c",
|
|
"%s",
|
|
"%p(\\d)",
|
|
"%P([A-z])",
|
|
"%g([A-z])",
|
|
"%'(.)'",
|
|
"%{([0-9]+)}",
|
|
"%l",
|
|
"%\\+|%-|%\\*|%/|%m",
|
|
"%&|%\\||%\\^",
|
|
"%=|%>|%<",
|
|
"%A|%O",
|
|
"%!|%~",
|
|
"%i",
|
|
"%(:[\\ #\\-\\+]{0,4})?(\\d+\\.\\d+|\\d+)?[doxXs]",
|
|
"%\\?(.*?);",
|
|
}
|
|
|
|
var regex *regexp.Regexp
|
|
var staticVar map[byte]stacker
|
|
|
|
// Parses the attribute that is received with name attr and parameters params.
|
|
func (term *TermInfo) Parse(attr string, params ...interface{}) (string, error) {
|
|
// Get the attribute name first.
|
|
iface, err := term.GetAttribute(attr)
|
|
str, ok := iface.(string)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
if !ok {
|
|
return str, errors.New("Only string capabilities can be parsed.")
|
|
}
|
|
// Construct the hidden parser struct so we can use a recursive stack based
|
|
// parser.
|
|
ps := &parser{}
|
|
// Dynamic variables only exist in this context.
|
|
ps.dynamicVar = make(map[byte]stacker, 26)
|
|
ps.parameters = make([]stacker, len(params))
|
|
// Convert the parameters to insert them into the parser struct.
|
|
for i, x := range params {
|
|
ps.parameters[i] = x
|
|
}
|
|
// Recursively walk and return.
|
|
result, err := ps.walk(str)
|
|
return result, err
|
|
}
|
|
|
|
// Parses the attribute that is received with name attr and parameters params.
|
|
// Only works on full name of a capability that is given, which it uses to
|
|
// search for the termcap name.
|
|
func (term *TermInfo) ParseName(attr string, params ...interface{}) (string, error) {
|
|
tc := GetTermcapName(attr)
|
|
return term.Parse(tc, params)
|
|
}
|
|
|
|
// Identify each token in a stack based manner and do the actual parsing.
|
|
func (ps *parser) walk(attr string) (string, error) {
|
|
// We use a buffer to get the modified string.
|
|
var buf bytes.Buffer
|
|
// Next, find and identify all tokens by their indices and strings.
|
|
tokens := regex.FindAllStringSubmatch(attr, -1)
|
|
if len(tokens) == 0 {
|
|
return attr, nil
|
|
}
|
|
indices := regex.FindAllStringIndex(attr, -1)
|
|
q := 0 // q counts the matches of one token
|
|
// Iterate through the string per character.
|
|
for i := 0; i < len(attr); i++ {
|
|
// If the current position is an identified token, execute the following
|
|
// steps.
|
|
if q < len(indices) && i >= indices[q][0] && i < indices[q][1] {
|
|
// Switch on token.
|
|
switch {
|
|
case tokens[q][0][:2] == "%%":
|
|
// Literal percentage character.
|
|
buf.WriteByte('%')
|
|
case tokens[q][0][:2] == "%c":
|
|
// Pop a character.
|
|
c, err := ps.st.pop()
|
|
if err != nil {
|
|
return buf.String(), err
|
|
}
|
|
buf.WriteByte(c.(byte))
|
|
case tokens[q][0][:2] == "%s":
|
|
// Pop a string.
|
|
str, err := ps.st.pop()
|
|
if err != nil {
|
|
return buf.String(), err
|
|
}
|
|
if _, ok := str.(string); !ok {
|
|
return buf.String(), errors.New("Stack head is not a string")
|
|
}
|
|
buf.WriteString(str.(string))
|
|
case tokens[q][0][:2] == "%p":
|
|
// Push a parameter on the stack.
|
|
index, err := strconv.ParseInt(tokens[q][1], 10, 8)
|
|
index--
|
|
if err != nil {
|
|
return buf.String(), err
|
|
}
|
|
if int(index) >= len(ps.parameters) {
|
|
return buf.String(), errors.New("Parameters index out of bound")
|
|
}
|
|
ps.st.push(ps.parameters[index])
|
|
case tokens[q][0][:2] == "%P":
|
|
// Pop a variable from the stack as a dynamic or static variable.
|
|
val, err := ps.st.pop()
|
|
if err != nil {
|
|
return buf.String(), err
|
|
}
|
|
index := tokens[q][2]
|
|
if len(index) > 1 {
|
|
errorStr := fmt.Sprintf("%s is not a valid dynamic variables index",
|
|
index)
|
|
return buf.String(), errors.New(errorStr)
|
|
}
|
|
// Specify either dynamic or static.
|
|
if index[0] >= 'a' && index[0] <= 'z' {
|
|
ps.dynamicVar[index[0]] = val
|
|
} else if index[0] >= 'A' && index[0] <= 'Z' {
|
|
staticVar[index[0]] = val
|
|
}
|
|
case tokens[q][0][:2] == "%g":
|
|
// Push a variable from the stack as a dynamic or static variable.
|
|
index := tokens[q][3]
|
|
if len(index) > 1 {
|
|
errorStr := fmt.Sprintf("%s is not a valid static variables index",
|
|
index)
|
|
return buf.String(), errors.New(errorStr)
|
|
}
|
|
var val stacker
|
|
if index[0] >= 'a' && index[0] <= 'z' {
|
|
val = ps.dynamicVar[index[0]]
|
|
} else if index[0] >= 'A' && index[0] <= 'Z' {
|
|
val = staticVar[index[0]]
|
|
}
|
|
ps.st.push(val)
|
|
case tokens[q][0][:2] == "%'":
|
|
// Push a character constant.
|
|
con := tokens[q][4]
|
|
if len(con) > 1 {
|
|
errorStr := fmt.Sprintf("%s is not a valid character constant", con)
|
|
return buf.String(), errors.New(errorStr)
|
|
}
|
|
ps.st.push(con[0])
|
|
case tokens[q][0][:2] == "%{":
|
|
// Push an integer constant.
|
|
con, err := strconv.ParseInt(tokens[q][5], 10, 32)
|
|
if err != nil {
|
|
return buf.String(), err
|
|
}
|
|
ps.st.push(con)
|
|
case tokens[q][0][:2] == "%l":
|
|
// Push the length of the string that is popped from the stack.
|
|
popStr, err := ps.st.pop()
|
|
if err != nil {
|
|
return buf.String(), err
|
|
}
|
|
if _, ok := popStr.(string); !ok {
|
|
errStr := fmt.Sprintf("Stack head is not a string")
|
|
return buf.String(), errors.New(errStr)
|
|
}
|
|
ps.st.push(len(popStr.(string)))
|
|
case tokens[q][0][:2] == "%?":
|
|
// If-then-else construct. First, the whole string is identified and
|
|
// then inside this substring, we can specify which parts to switch on.
|
|
ifReg, _ := regexp.Compile("%\\?(.*)%t(.*)%e(.*);|%\\?(.*)%t(.*);")
|
|
ifTokens := ifReg.FindStringSubmatch(tokens[q][0])
|
|
var (
|
|
ifStr string
|
|
err error
|
|
)
|
|
// Parse the if-part to determine if-else.
|
|
if len(ifTokens[1]) > 0 {
|
|
ifStr, err = ps.walk(ifTokens[1])
|
|
} else { // else
|
|
ifStr, err = ps.walk(ifTokens[4])
|
|
}
|
|
// Return any errors
|
|
if err != nil {
|
|
return buf.String(), err
|
|
} else if len(ifStr) > 0 {
|
|
// Self-defined limitation, not sure if this is correct, but didn't
|
|
// seem like it.
|
|
return buf.String(), errors.New("If-clause cannot print statements")
|
|
}
|
|
var thenStr string
|
|
// Pop the first value that is set by parsing the if-clause.
|
|
choose, err := ps.st.pop()
|
|
if err != nil {
|
|
return buf.String(), err
|
|
}
|
|
// Switch to if or else.
|
|
if choose.(int) == 0 && len(ifTokens[1]) > 0 {
|
|
thenStr, err = ps.walk(ifTokens[3])
|
|
} else if choose.(int) != 0 {
|
|
if len(ifTokens[1]) > 0 {
|
|
thenStr, err = ps.walk(ifTokens[2])
|
|
} else {
|
|
thenStr, err = ps.walk(ifTokens[5])
|
|
}
|
|
}
|
|
if err != nil {
|
|
return buf.String(), err
|
|
}
|
|
buf.WriteString(thenStr)
|
|
case tokens[q][0][len(tokens[q][0])-1] == 'd': // Fallthrough for printing
|
|
fallthrough
|
|
case tokens[q][0][len(tokens[q][0])-1] == 'o': // digits.
|
|
fallthrough
|
|
case tokens[q][0][len(tokens[q][0])-1] == 'x':
|
|
fallthrough
|
|
case tokens[q][0][len(tokens[q][0])-1] == 'X':
|
|
fallthrough
|
|
case tokens[q][0][len(tokens[q][0])-1] == 's':
|
|
token := tokens[q][0]
|
|
// Remove the : that comes before a flag.
|
|
if token[1] == ':' {
|
|
token = token[:1] + token[2:]
|
|
}
|
|
digit, err := ps.st.pop()
|
|
if err != nil {
|
|
return buf.String(), err
|
|
}
|
|
// The rest is determined like the normal formatted prints.
|
|
digitStr := fmt.Sprintf(token, digit.(int))
|
|
buf.WriteString(digitStr)
|
|
case tokens[q][0][:2] == "%i":
|
|
// Increment the parameters by one.
|
|
if len(ps.parameters) < 2 {
|
|
return buf.String(), errors.New("Not enough parameters to increment.")
|
|
}
|
|
val1, val2 := ps.parameters[0].(int), ps.parameters[1].(int)
|
|
val1++
|
|
val2++
|
|
ps.parameters[0], ps.parameters[1] = val1, val2
|
|
default:
|
|
// The rest of the tokens is a special case, where two values are
|
|
// popped and then operated on by the token that comes after them.
|
|
op1, err := ps.st.pop()
|
|
if err != nil {
|
|
return buf.String(), err
|
|
}
|
|
op2, err := ps.st.pop()
|
|
if err != nil {
|
|
return buf.String(), err
|
|
}
|
|
var result stacker
|
|
switch tokens[q][0][:2] {
|
|
case "%+":
|
|
// Addition
|
|
result = op2.(int) + op1.(int)
|
|
case "%-":
|
|
// Subtraction
|
|
result = op2.(int) - op1.(int)
|
|
case "%*":
|
|
// Multiplication
|
|
result = op2.(int) * op1.(int)
|
|
case "%/":
|
|
// Division
|
|
result = op2.(int) / op1.(int)
|
|
case "%m":
|
|
// Modulo
|
|
result = op2.(int) % op1.(int)
|
|
case "%&":
|
|
// Bitwise AND
|
|
result = op2.(int) & op1.(int)
|
|
case "%|":
|
|
// Bitwise OR
|
|
result = op2.(int) | op1.(int)
|
|
case "%^":
|
|
// Bitwise XOR
|
|
result = op2.(int) ^ op1.(int)
|
|
case "%=":
|
|
// Equals
|
|
result = op2 == op1
|
|
case "%>":
|
|
// Greater-than
|
|
result = op2.(int) > op1.(int)
|
|
case "%<":
|
|
// Lesser-than
|
|
result = op2.(int) < op1.(int)
|
|
case "%A":
|
|
// Logical AND
|
|
result = op2.(bool) && op1.(bool)
|
|
case "%O":
|
|
// Logical OR
|
|
result = op2.(bool) || op1.(bool)
|
|
case "%!":
|
|
// Logical complement
|
|
result = !op1.(bool)
|
|
case "%~":
|
|
// Bitwise complement
|
|
result = ^(op1.(int))
|
|
}
|
|
ps.st.push(result)
|
|
}
|
|
|
|
i = indices[q][1] - 1
|
|
q++
|
|
} else {
|
|
// We are not "inside" a token, so just skip until the end or the next
|
|
// token, and add all characters to the buffer.
|
|
j := i
|
|
if q != len(indices) {
|
|
for !(j >= indices[q][0] && j < indices[q][1]) {
|
|
j++
|
|
}
|
|
} else {
|
|
j = len(attr)
|
|
}
|
|
buf.WriteString(string(attr[i:j]))
|
|
i = j
|
|
}
|
|
}
|
|
// Return the buffer as a string.
|
|
return buf.String(), nil
|
|
}
|
|
|
|
// Push a stacker-value onto the stack.
|
|
func (st *stack) push(s stacker) {
|
|
*st = append(*st, s)
|
|
}
|
|
|
|
// Pop a stacker-value from the stack.
|
|
func (st *stack) pop() (stacker, error) {
|
|
if len(*st) == 0 {
|
|
return nil, errors.New("Stack is empty.")
|
|
}
|
|
newStack := make(stack, len(*st)-1)
|
|
val := (*st)[len(*st)-1]
|
|
copy(newStack, (*st)[:len(*st)-1])
|
|
*st = newStack
|
|
return val, nil
|
|
}
|
|
|
|
// Initialize regexes and the static vars (that don't get changed between
|
|
// calls.
|
|
func init() {
|
|
// Initialize the main regex.
|
|
expStr := strings.Join(exp[:], "|")
|
|
regex, _ = regexp.Compile(expStr)
|
|
// Initialize the static variables.
|
|
staticVar = make(map[byte]stacker, 26)
|
|
}
|