Quick script to set labels of vfat volumes. Useful to name usb sticks.

labelstick

#!/usr/bin/env python
import os
import re
import signal
import subprocess
import sys

from PyQt4.QtCore import *
from PyQt4.QtGui import *

class MtoolsError(Exception):
    def __init__(self, cmd, output):
        self.cmd = cmd
        self.output = output

    def __str__(self):
        return "command: {}\noutput: {}".format(self.cmd, self.output)

def failure(msg):
    QMessageBox.critical(None, qApp.tr("Error"), msg, QMessageBox.Close)

def getLabel(device):
    out_prefix1 = re.compile("^ Volume label is (.+[^ ]) +\(.*\)$")
    out_prefix2 = re.compile("^ Volume label is (.+[^ ]) +$")
    cmd = ["mlabel", "-i", device, "-s", "::"]
    print("Running {}".format(cmd))
    try:
        out = subprocess.check_output(cmd, stderr=subprocess.STDOUT)
    except subprocess.CalledProcessError, exc:
        raise MtoolsError(cmd, exc.output)
    print("Output: {}".format(out))
    match = out_prefix1.match(out)
    if match:
        return match.group(1)
    match = out_prefix2.match(out)
    if match:
        return match.group(1)
    if out.strip() == "Volume has no label":
        return ""
    raise Exception("Unexpected out from mlabel: {}".format(out))

def setLabel(device, label):
    cmd = ["mlabel", "-i", device, "::" + label]
    print("Running {}".format(cmd))
    return subprocess.call(cmd, stderr=subprocess.STDOUT)

def main():
    signal.signal(signal.SIGINT, signal.SIG_DFL)
    app = QApplication(sys.argv)

    if len(sys.argv) != 2:
        failure("Usage: <tt>labelstick &lt;/dev/path&gt;</tt>")
        return 1
    if os.getuid() != 0:
        return os.execlp("kdesudo", "python", *sys.argv)
    device = sys.argv[1]
    try:
        label = getLabel(device)
    except MtoolsError, exc:
        failure(
            app.tr("<p>Labelstick failed to read label for partition <tt>%1</tt>.</p>"
                "<p>Make sure the partition name is correct and is a VFAT partition.</p>"
                "<p>Detailed error:</p><pre>%2</pre>"
                ).arg(device).arg(str(exc))
            )
        return 1
    newLabel, ok = QInputDialog.getText(None, app.tr("Label partition %1").arg(device),
        app.tr("Please enter a label for partition (11 characters maximum):"),
        QLineEdit.Normal,
        label)
    if not ok:
        return 0
    newLabel = newLabel[:11]

    if label != newLabel:
        try:
            setLabel(device, newLabel)
        except subprocess.CalledProcessError:
            failure("Failed to set label.")

    return 0

if __name__ == "__main__":
    sys.exit(main())
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