我很难在 Ruby 中读取带有转义字符的文件...
我的文本文件有字符串“First Line\r\nSecond Line”，当我使用 File.read 时，我得到一个字符串，它转义了我的转义字符：“First Line\r\nSecond Line”
这两个字符串不是一回事...
1.9.2-p318 :006 > f = File.read("file.txt")
=> "First Line\\r\\nSecond Line"
1.9.2-p318 :007 > f.count('\\')
=> 2
1.9.2-p318 :008 > f = "First Line\r\nSecond Line"
=> "First Line\r\nSecond Line"
1.9.2-p318 :009 > f.count('\\')
=> 0
如何让 File.read 不转义我的转义字符？
创建一个方法来删除 File.Read 方法添加的所有其他转义字符，如下所示：
# Define a method to handle unescaping the escape characters
def unescape_escapes(s)
s = s.gsub("\\\\", "\\") #Backslash
s = s.gsub('\\"', '"') #Double quotes
s = s.gsub("\\'", "\'") #Single quotes
s = s.gsub("\\a", "\a") #Bell/alert
s = s.gsub("\\b", "\b") #Backspace
s = s.gsub("\\r", "\r") #Carriage Return
s = s.gsub("\\n", "\n") #New Line
s = s.gsub("\\s", "\s") #Space
s = s.gsub("\\t", "\t") #Tab
s
end
然后看看它的实际效果：
# Create your sample file
f = File.new("file.txt", "w")
f.write("First Line\\r\\nSecond Line")
f.close
# Use the method to solve your problem
f = File.read("file.txt")
puts "BEFORE:", f
puts f.count('\\')
f = unescape_escapes(f)
puts "AFTER:", f
puts f.count('\\')
# Here's a more elaborate use of it
f = File.new("file2.txt", "w")
f.write("He used \\\"Double Quotes\\\".")
f.write("\\nThen a Backslash: \\\\")
f.write('\\nFollowed by \\\'Single Quotes\\\'.')
f.write("\\nHere's a bell/alert: \\a")
f.write("\\nThis is a backspaces\\b.")
f.write("\\nNow we see a\\rcarriage return.")
f.write("\\nWe've seen many\\nnew lines already.")
f.write("\\nHow\\sabout\\ssome\\sspaces?")
f.write("\\nWe'll also see some more:\\n\\ttab\\n\\tcharacters")
f.close
# Read the file without the method
puts "", "BEFORE:"
puts File.read("file2.txt")
# Read the file with the method
puts "", "AFTER:"
puts unescape_escapes(File.read("file2.txt"))
你可以把它们黑回去。
foo = f.gsub("\r\n", "\\r\\n")
#=> "First Line\\r\\nSecond Line"
foo.count("\\")
#=> 2