Batch : read lines from a file having spaces in it

问题:

To read lines from a file, in a batch file, you do :

for /f %%a in (myfile.txt) do (
    :: do stuff...
)

Now suppose you file is in C:\Program Files\myfolder

for /f %%a in ("C:\Program Files\myfolder\myfile.txt") do (
    echo %%a
)

Result :

C:\Program Files\myfolder\myfile.txt

This seems to interpret the given path as a string, and thus %%a is your given path.

Nothing about this in the documentation I have found so far. Please someone help me before I shoot myself.

回答1:

The documentation you get when you type help for tells you what to do if you have a path with spaces.

For file names that contain spaces, you need to quote the filenames with
double quotes.  In order to use double quotes in this manner, you also
need to use the usebackq option, otherwise the double quotes will be
interpreted as defining a literal string to parse.

By default, the syntax of FOR /F is the following.

FOR /F ["options"] %variable IN (file-set) DO command [command-parameters]
FOR /F ["options"] %variable IN ("string") DO command [command-parameters]
FOR /F ["options"] %variable IN ('command') DO command [command-parameters]

This syntax shows why your type workaround works. Because the single quotes say to execute the type command and loop over its output. When you add the usebackq option, the syntax changes to this:

FOR /F ["options"] %variable IN (file-set) DO command [command-parameters]
FOR /F ["options"] %variable IN ('string') DO command [command-parameters]
FOR /F ["options"] %variable IN (`command`) DO command [command-parameters]

Now you double quote paths to files, single-quote literal strings, and put backticks (grave accents) around commands to execute.

So you want to do this:

for /f "usebackq" %%a in ("C:\Program Files\myfolder\myfile.txt") do (
    echo %%a
)

回答2:

Found it.

for /f %%a in ('type "C:\Program Files\myfolder\myfile.txt"') do (
    echo Deleting: %%a
)

Don't even ask me why that works.

回答3:

Just sharing the below code, hoping that somebody will get benefited.

The below code take both the path having spaces and also if the read lines has spaces, it wont cause any issue of the characters after space is missing;

FOR /f "tokens=* delims=," %%a in ('type "C:\Progrem File\My Program"') do ( echo %%a )