Solve practical problems on batch file

Batniki is not a powerful programming language, but at the same time, it can solve many routine tasks. The purpose of the article is not just to tell about the capabilities of the Windows-console, but to show them, solving practical problems that I had to face.

Confirmation of execution

  set answer =
 set / p answer = "Run? [y / n]:"
 if not "% answer%" == "y" exit / b 

Set the answer variable to an empty value (necessary to overwrite the previous value, for example, if the batch file is executed several times). set with the / p key sets the value of a variable that is entered by the user. Check the value of the variable, and if it is not equal to y, terminate the batch file.
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How to get the current month, day, year, etc.?

In batch files, it is possible to get a substring using the syntax% variable: ~ m, n% Where variable is the name of the variable m is the index of the first character, and n is the number of characters of the substring.

Therefore, if the echo% date% command (and the date format may differ from you) will be output on 13.06.2009, in order to get the current month, it’s enough to do% date: ~ 3.2% Thus, if we need to, for example, generate the name file or directory that corresponds to the current month and day, we will do it like this:

  set fname =% date: ~ 3.2 %% date: ~ 0.2% 

Personally, I needed this to set the / d key for xcopy.

How to display an empty line in the log file?

I did not immediately realize that it could be done like this: :)

  echo. >>% logfile% 

Those. need to put a dot after echo.

Did the previous command succeed?

In most cases this is:

  if% errorlevel% == 0 (
   echo OK >>% logfile%
 ) else (
   echo ERROR #% errorlevel% >>% logfile%
 ) 

Archiving a variable name file

  for %% i in (c: \ dir \ #fe *. *) do rar a -ep c: \ other_dir \ %% ~ ni.rar %% i 

The task is to archive a file with a name that changes daily, but in a different folder. The next piece of code

  for %% i in (c: \ dir \ #fe *. *) do 

we select all files by mask by executing the command rar a -ep c: \ other_dir \ %% ~ ni.rar %% i for each, where %% ~ ni is just the file name.

The name of the current executable batch file

  % ~ n0 

It is necessary, for example, to keep one log for several batch files.

"Function" in batch file

If we execute several duplicate commands in one batch file, but with different values ​​of variables, then this can be done like this:

  set thebat = c: \ Program Files \ The Bat! \ thebat.exe
 set action = SEND

 set mailto=email_1@domain.com
 set subject = Subject_1
 set attach = c: \ dir \ file ????
 call: mailit


 set mailto=email_2@domain.com
 set subject = Subject_2
 set attach = c: \ dir \ file * .rar
 call: mailit

 ...

 exit

 : mailit
 @echo on
 "% thebat%" / MAILTO = "% mailto%"; SUBJECT = "% subject%"; ATTACH = "% attach%";% action% >>% logfile%
 @echo off
 exit / b 

Thus, I have sent a dozen different files to different recipients using The Bat! Such a file to read and edit is much more convenient than it would be ten teams The Bat! contract.

Get the last file created by date

First we get a list of all files sorted by modification date:

  dir / b / od / ad c: \ dir \ file _ *. xls 

And go through it cycle.

  for / f "tokens = *" %% a in ('dir / b / od / ad c: \ dir \ file _ *. xls') do set "lastfile = %% a" 

It is logical that at the end of the cycle in the variable% lastfile% we will have the last file by modification date;)

Download file via FTP

  ftp -s: file_to_ftp.txt 127.0.0.1 

Where the file file_to_ftp.txt will look like this:

  login
 password
 bin 
 cd / files
 put file.xls 
 quit 

Create numbered directories with an increment of one

  set dir_last =
 for / f "tokens = *" %% i in ('dir / ad / b') do set dir_last = %% i

 if '% dir_last%' == '' (set dir_last = 000)

 set dir_last = 1% dir_last%
 set / a dir_last =% dir_last% - 1000
 set / a dir_new =% dir_last% + 1

 set dir_new = 00% dir_new%
 set dir_new =% dir_new: ~ -3%
 md% dir_new% 

Understand the code suggest yourself. :) The main possibility that I wanted to show with this example is the use of the / a switch on the set command to evaluate expressions. ;)