122 lines
3.5 KiB
Go
122 lines
3.5 KiB
Go
package instances
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/json"
|
|
"errors"
|
|
"strings"
|
|
|
|
"github.com/tkw1536/goprogram/stream"
|
|
)
|
|
|
|
var ErrExecInvalidCode = errors.New("invalid code to execute")
|
|
var ErrExecNonZero = errors.New("script returned non-zero code")
|
|
|
|
// ExecPHPScript executes the PHP code as a script within the wisski instance.
|
|
// The script should define a function "main", and may define additional functions.
|
|
//
|
|
// Code must start with "<?php" and may not contain a closing tag.
|
|
// Code is expected not to mess with PHPs output buffer.
|
|
// Code should not contain user input.
|
|
//
|
|
// It's arguments are encoded as json using [json.Marshal] and decoded within php.
|
|
//
|
|
// The return value of the function is again marshaled with json and returned to the caller.
|
|
//
|
|
// Standard input and output streams should not be used.
|
|
// Standard error is redirected to io.
|
|
func (wisski *WissKI) ExecPHPScript(io stream.IOStream, code string, args ...any) (any, error) {
|
|
// make sure the beginning is right
|
|
if !strings.HasPrefix(code, "<?php") {
|
|
return nil, ErrExecInvalidCode
|
|
}
|
|
|
|
// make sure that args is not nil, but an array of length 0!
|
|
if args == nil {
|
|
args = []any{}
|
|
}
|
|
|
|
// encode code and args!
|
|
codeEscape, err := marshalPHP("?>" + code)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
argsEscape, err := marshalPHP(args)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// assemble the script
|
|
script := `
|
|
ob_start(null, 0, PHP_OUTPUT_HANDLER_CLEANABLE);
|
|
eval(` + codeEscape + `);
|
|
ob_end_clean();
|
|
|
|
call_user_func(function(){
|
|
ob_start(null, 0, PHP_OUTPUT_HANDLER_CLEANABLE);
|
|
$result = call_user_func_array("main", ` + argsEscape + `);
|
|
ob_end_clean();
|
|
echo json_encode($result);
|
|
});
|
|
`
|
|
|
|
// run the script
|
|
var output bytes.Buffer
|
|
res, err := wisski.Shell(io.Streams(&output, nil, strings.NewReader(script), 0), "-c", "drush php:script -")
|
|
if res != 0 {
|
|
return nil, ErrExecNonZero
|
|
}
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// decode the output
|
|
var result any
|
|
err = json.NewDecoder(&output).Decode(&result)
|
|
return result, err
|
|
}
|
|
|
|
// EvalPHP is similar to ExecPHPScript, except that it evaluates a single line of php.
|
|
// A single parameter may be passed, which can be accessed using the name $arg inside the expression.
|
|
func (wisski *WissKI) EvalPHP(expr string, arg any) (any, error) {
|
|
return wisski.ExecPHPScript(stream.FromEnv(), "function main($arg){return "+expr+";}", arg)
|
|
}
|
|
|
|
const marshalRune = 'F' // press to pay respect
|
|
|
|
// marshalPHP marshals some data which can be marshaled using [json.Encode] into a PHP Expression.
|
|
// the string can be safely used directly within php.
|
|
func marshalPHP(data any) (string, error) {
|
|
// this function uses json as a data format to transport the data into php.
|
|
// then we build a heredoc to encode it safely, and decode it in php
|
|
|
|
// Step 1: Encode the data as json
|
|
jbytes, err := json.Marshal(data)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
jstring := string(jbytes)
|
|
|
|
// Step 2: Find a delimiter for the heredoc.
|
|
// Step 2a: Find the longest sequence of [marshalRune]s inside the encoded string.
|
|
var current, longest int
|
|
for _, r := range jstring {
|
|
|
|
if r == marshalRune {
|
|
current++
|
|
} else {
|
|
current = 0
|
|
}
|
|
|
|
if current > longest {
|
|
longest = current
|
|
}
|
|
}
|
|
// Step 2b: Build a string of marshalRune that is one longer!
|
|
delim := strings.Repeat(string(marshalRune), longest+1)
|
|
|
|
// Step 3: Assemble the encoded string!
|
|
result := "call_user_func(function(){$x=<<<'" + delim + "'\n" + jstring + "\n" + delim + ";return json_decode(trim($x));})" // press to doubt
|
|
return result, nil
|
|
}
|