以下代码旨在删除与正则表达式匹配的行失败
def delete_entry(name)
puts "Deleting #{name}.." if $DEBUG
begin
File.open("#{@file_name}.tmp", 'w') do |out_file|
File.open(@file_name, 'r').each do |line|
unless line =~ /^#{name},/
out_file.print line
else
puts "Deleted #{line}!"
end
end
end
File.delete(@file_name)
File.rename("#{@file_name}.tmp", @file_name)
rescue Exception
puts "Exception thrown in PhoneBook::delete_entry(#{name}): #{$!}"
end
end
临时文件工作得很好。相应的条目被正确删除。但是当我尝试删除旧文件并将 tmp 重命名为新文件时,File.delete 会抛出以下内容:(第 56 行是对 File#delete 的调用)
Exception `Errno::EACCES' at PhoneBook.rb:56 - Permission denied - file-io-sampl
es/phonebooks/test.csv
Exception thrown in PhoneBook::delete_entry(Mike): Permission denied - file-io-s
amples/phonebooks/test.csv
任何帮助,将不胜感激。如果有帮助的话,这是在使用 NTFS 文件系统的 Windows 7 上。
编辑:根据我在评论中添加的 Az 的建议:
ObjectSpace.each_object(File) { |f| p f if f.path == @file_name && !f.closed? }
就在调用 File.delete 之前。输出如下:
C:\Pickaxe>ruby PhoneBook.rb true
Enter a phonebook!
test.csv
Using test.csv..
Open Called!
Name: Richard Sex: Male Age: 22
Name: Midori Sex: Female Age: 22
Name: Mike Sex: Male Age: 18
Name: Richard Sex: Male Age: 44
Deleting Mike..
Deleted Mike,Male, 18
!
#<File:file-io-samples/phonebooks/test.csv>
#<File:file-io-samples/phonebooks/test.csv>
Exception `Errno::EACCES' at PhoneBook.rb:56 - Permission denied - file-io-sampl
es/phonebooks/test.csv
Exception thrown in PhoneBook::delete_entry(Mike): Permission denied - file-io-s
amples/phonebooks/test.csv
C:\Pickaxe>
以 # 为前缀的两行是 ObjectSpace 调用的输出。