Batch Commands To Read and Delete Lines from txt-File

[officer07]

Hi there,

first of all I have a file named "directory.txt" which contains all
filenames of a certain directory (some thousand files or so) and looks like
this:

importantfile1.doc
nicework.ppt
salary09.xls
salary08.xls
....

All these files need to be encrypted with a special program (GnuPG, but that
is rather unimportant).
Therefore I need to create a batch file that reads the first line of
"directory.txt", puts the information into a variable and then deletes that
line from the file and then passes the information in the variable on to the
encryption program (as a parameter, see below).
It is important that the line is deleted from the "directory.txt" before the
encryption program is being executed, so that another thread of that batch
file that would be started some time later does not start to encrypt the same
file again.

For now, I have already created the following "one-liner":

FOR /F "delims=" %%i IN ('TYPE directory.txt') DO echo
secretpassphrase|gpg.exe --passphrase-fd 0 -v -c "%%i"

What I have not been able to accomplish yet, is to delete the line in
question from the directory.txt BEFORE gpg.exe is being executed.
In some imaginative pseudocode I imagine this would look somewhat like this:

========================
x = CountLines(directory.txt);
FOR i = 0 to x DO
BEGIN
$filename = READLINE(i) from directory.txt;
DELETELINE(i) from directory.txt;
echo secretpassphrase|gpg.exe --passphrase-fd 0 -v -c "$filename"
END;
========================

I hope you can understand my problem and help me somehow to find the
commands to accomplish this.
The goal is to be able to start this "program" like five or ten times in
parallel, so that the task of encrypting all files in the directory is
accomplished faster that if only one file could be encrypted at a time.

I would also happily try to do this using VBS or something like that. The
only point is that the line that executes the encryption program, namely:
echo secretpassphrase|gpg.exe --passphrase-fd 0 -v -c "$filename"
should stay as it is (except for the variable containing the filename at the
end, of course). This is, because the passphrase can only be entered
interactively (which is done here by a pipe that passes it on to fd0, kind
of).

Any help will be appreciated very much!
Thank you all in advance,

yours,
officer07

[Mervyn Zhang [MSFT]]

Hi,

Thank you for posting here.

According to your description, I understand that:

You would like to read and delete the first line of a TXT file.

If I have misunderstood the problem, please don't hesitate to let me know.

The following bat file will delete the first line of directory.txt. You can
"call" it in your original bat file to delete first of directory.txt. For
more information about Call, please refer to the following article:
Call
http://technet.microsoft.com/en-us/l.../bb490873.aspx


@echo off
for /f "skip=1 tokens=*" %%A in (directory.txt) do echo %%A >> d2.txt
del d.txt
rename d2.txt directory.txt

This bat file create a new file without the first line of original file and
then delete original file and rename new file. It performance may be not
good. You may get error message if there is only one line left in
directory.txt file.

At the same time, I suggest that you initial a new post in the MSDN form to
get further support there. They are the best resource for development
related problems.

For your convenience, I have list the link as followed.

MSDN Forum
http://forums.microsoft.com/MSDN/default.aspx?SiteID=1

Sincerely,
Mervyn Zhang
Microsoft Online Community Support

==================================================
This posting is provided "AS IS" with no warranties, and confers no rights.

[Pegasus \(MVP\)]

"officer07" <officer07@newsgroup.nospam> wrote in message
news:F435EE47-872B-4755-AA2E-F9BBCE97220C@microsoft.com...
> Hi there,
>
> first of all I have a file named "directory.txt" which contains all
> filenames of a certain directory (some thousand files or so) and looks
> like
> this:
>
> importantfile1.doc
> nicework.ppt
> salary09.xls
> salary08.xls
> ...
>
> All these files need to be encrypted with a special program (GnuPG, but
> that
> is rather unimportant).
> Therefore I need to create a batch file that reads the first line of
> "directory.txt", puts the information into a variable and then deletes
> that
> line from the file and then passes the information in the variable on to
> the
> encryption program (as a parameter, see below).
> It is important that the line is deleted from the "directory.txt" before
> the
> encryption program is being executed, so that another thread of that batch
> file that would be started some time later does not start to encrypt the
> same
> file again.
>
> For now, I have already created the following "one-liner":
>
> FOR /F "delims=" %%i IN ('TYPE directory.txt') DO echo
> secretpassphrase|gpg.exe --passphrase-fd 0 -v -c "%%i"
>
> What I have not been able to accomplish yet, is to delete the line in
> question from the directory.txt BEFORE gpg.exe is being executed.
> In some imaginative pseudocode I imagine this would look somewhat like
> this:
>
> ========================
> x = CountLines(directory.txt);
> FOR i = 0 to x DO
> BEGIN
> $filename = READLINE(i) from directory.txt;
> DELETELINE(i) from directory.txt;
> echo secretpassphrase|gpg.exe --passphrase-fd 0 -v -c "$filename"
> END;
> ========================
>
> I hope you can understand my problem and help me somehow to find the
> commands to accomplish this.
> The goal is to be able to start this "program" like five or ten times in
> parallel, so that the task of encrypting all files in the directory is
> accomplished faster that if only one file could be encrypted at a time.
>
> I would also happily try to do this using VBS or something like that. The
> only point is that the line that executes the encryption program, namely:
> echo secretpassphrase|gpg.exe --passphrase-fd 0 -v -c "$filename"
> should stay as it is (except for the variable containing the filename at
> the
> end, of course). This is, because the passphrase can only be entered
> interactively (which is done here by a pipe that passes it on to fd0, kind
> of).
>
> Any help will be appreciated very much!
> Thank you all in advance,
>
> yours,
> officer07

You could solve this problem either with a batch file or with VB Script. The
batch file would a little shorter but it has one big drawback: It would not
be particularly robust. If the file "directory.txt" contains any "poison"
characters such as ", ', %, ^,(,), & etc. then it's likely to fail. A VB
Script solution would not be subject to this restriction.

Which would you prefer, batch or VB?

[Mervyn Zhang [MSFT]]

Hi,

Would you mind letting me know the result of the suggestions? If you need
further assistance, feel free to let me know. I will be more than happy to
be of assistance.

Sincerely,
Mervyn Zhang
Microsoft Online Community Support

==================================================
This posting is provided "AS IS" with no warranties, and confers no rights.