File Functions

Overview

• File module functions handle file operations
• The file module uses the file prefix, e.g. file.readFile()

file.readFile Read as String

• Read a file as a string
• @param path File path
• @return string

function main() {
    var data = file.readFile("/sdcard/test.txt");
    toast(data);
}

main();

file.deleteLine Delete a Line

• Delete a line by number or by matching content
• Note: if deletion fails, use readAllLines, find the line index, delete it, then save
• @param path File path
• @param line Line number; -1 disables this condition
• @param contains Delete lines containing this string; null disables this condition
• @return {bool} true on success, false on failure

function main() {
    // Delete lines containing "time"
    let r = file.deleteLine("/sdcard/a.txt", -1, "time");
    logd("r " + r);
    // Delete line 3
    r = file.deleteLine("/sdcard/a.txt", 3, null);
    logd("r " + r);
}

main();

file.listDir List Files

• List all files under a path
• @param path Path
• @return array of path strings

function main() {
    var data = file.listDir("/sdcard/");
    for (var i = 0; i < data.length; i++) {
        logd("path " + data[i]);
    }

}

main();

file.writeFile Write File

• Write a string to a file
• @param data String data
• @param path File path

function main() {
    var data = "Test";
    file.writeFile(data, "/sdcard/test.txt");
}

main();

file.create Create File

• Create a file
• @param path File path
• @return boolean true if created successfully

function main() {
    var create = file.create("/sdcard/test.txt");
    toast(create);
}

main();

file.mkdirs Create Directory

• Create a directory
• @param path Path
• @return boolean true on success, false on failure

function main() {
    var t = file.mkdirs("/sdcard/testdir/");
    toast(t);
}

main();

file.readAssets Read from assets

• Read data from the APK assets folder as a string
• @param path Path under assets, e.g. data/a.txt
• @return string

function main() {
    var data = file.readAssets("data/test.txt");
    toast(data);
}

main();

file.deleteAllFile Delete

• Delete a file or folder
• @param path File or folder path

function main() {
    // Delete file
    file.deleteAllFile("/sdcard/test.txt");
    // Delete folder
    file.deleteAllFile("/sdcard/testdir/");
}

main();

file.appendLine Append Line

• Append one line to a file
• @param data Line data
• @param path File path
• @return boolean true on success, false on failure

function main() {
    var data = "sss";
    var t = file.appendLine(data, "/sdcard/test.txt");
    toast(t);
}

main();

file.readLine Read One Line

• Read one line; returns empty if the line number is invalid
• @param path Path
• @param lineNo Line number
• @return string

function main() {
    var t = file.readLine("/sdcard/test.txt", 1);
    toast(t);
}

main();

file.readAllLines Read All Lines

• Read all lines
• @param path Path
• @return string array|null

function main() {
    var t = file.readAllLines("/sdcard/test.txt");
    toast(t);
}

main();

file.exists Check Existence

• Check whether a file or folder exists
• @param path Path
• @return boolean true if it exists, false otherwise

function main() {
    var t = file.exists("/sdcard/testdir/");
    toast(t);
}

main();

file.copy Copy File

• Copy a file
• @param src Source path
• @param dest Destination path
• @return boolean true on success

function main() {
    var t = file.copy("/sdcard/a.png", "/sdcard/b.png");
    toast(t);
}

main();