Report if file is locked for import command instead of hanging

[RohanVashisht1234]

The database import process gets stuck infinitely, if the database file is locked, it shows uploading without actually uploading, and also doesn't give any warning regarding this.

I have implemented that it will show an error if the database is locked.

test2.mov

[Copilot]

Pull request overview

This PR aims to prevent turso db import <filename> from appearing to hang indefinitely when the source SQLite database file is locked, by detecting the locked state early and returning a clear error.

Changes:

• Added a helper to check whether the target file is locked.
• Added a pre-flight lock check in the db import command to fail fast with a user-friendly error.

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[avinassh]

what if this fails?

[avinassh]

Suggested change

	func isFileLocked(filename string) (bool, error) {
	f, err := os.Open(filename)
	if err != nil {
	return false, err
	}
	defer f.Close()
	err = syscall.Flock(int(f.Fd()), syscall.LOCK_EX|syscall.LOCK_NB)
	if err != nil {
	if errors.Is(err, syscall.EWOULDBLOCK) {
	return true, nil // File is locked
	}
	return false, fmt.Errorf("failed to check lock: %w", err)
	}
	syscall.Flock(int(f.Fd()), syscall.LOCK_UN)
	return false, nil
	}
	func isFileLocked(filename string) (bool, error) {
	f, err := os.Open(filename)
	if err != nil {
	return false, fmt.Errorf("failed to open file: %w", err)
	}
	defer f.Close()
	fd := int(f.Fd())
	err = syscall.Flock(fd, syscall.LOCK_EX|syscall.LOCK_NB)
	if err != nil {
	if errors.Is(err, syscall.EWOULDBLOCK) {
	return true, nil
	}
	return false, fmt.Errorf("failed to acquire lock: %w", err)
	}
	if err := syscall.Flock(fd, syscall.LOCK_UN); err != nil {
	return false, fmt.Errorf("failed to release lock: %w", err)
	}
	return false, nil
	}

[RohanVashisht1234]

Ok, now I think I have done all the nessecary changes.