So I'm trying to save the contents from the second line of a text file as a variable using Batch. I know there are way better scripting languages to do this with, but batch has command line simplicity that I need. I found this webpage: http://www.netikka.net/tsneti/info/tscmd023.htm But it seems that this method requires an auxiliary program called SED be installed. Are there any methods that do not require SED?
A for loop could work ..
#echo off
Setlocal enabledelayedexpansion
For /f "skip=1 tokens=*" %%a in (myfile.txt) do (
Set secondline=%%a
goto finish
)
: finish
Echo this is my variable !secondline!
Pause
Related
I have a small problem with a .bat file that I have to build to manipulate a specific .csv.
I want the .bat to read the line of the file, and then check for the first three letters of that line. At the end there should be n-files where file xxx.csv contains the lines of the input.csv with xxx as the first three letters of line.
First things first, I don't even know if it is possible to do it this job in a batch-file, because the file has >85000 lines and may even get much bigger. So if it is impossible you can directly tell me that.
for /f "delims=" %%a in (input.CSV) DO (
echo %%~a:~0,3
pause
)
I want to "output" the first three letters of %%a.
It would be great if you could help me.
Phil
Substring substitution only works with environment variables (%var%), but not with metavariables (%%a) (as Mofi already commented). And because you are setting and using a variable within the same command block, you need delayed expansion:
setlocal enabledelayedexpansion
for /f "delims=" %%a in (input.CSV) DO (
set "var=%%~a"
echo !var:~0,3!
pause
)
(there are methods without delayed expansion, but they make use of call, which slows things down)
Suppose I have a text file with following contents:
Hello
World
Abc
Now I want to read this in batch and copy them into a single variable. So my variable should contain:
var=Hello World Abc
What is possible work around for this?
If I am trying I am either getting the first word or the last line word.
Thanks
This seems to work. I have appended \n to each line in the read file. I'm not sure how you expect that behavior to actually work:
#echo off
SETLOCAL EnableDelayedExpansion
set "filecontents="
for /f "delims=" %%x in (input.txt) do (
set filecontents=!filecontents!%%x\n
)
echo %filecontents%
To read the contents of a file in a batch file you can use a FOR /F command. You then use the SET command to assign a value to a variable. Also, you will need to utilized delayed expansion to reassign the existing variable to the original variable. A leading space will get assigned so the echo command is using a substring to remove it.
#echo off
setlocal EnableDelayedExpansion
for /f "delims=" %%G IN (file.txt) do set "var=!var! %%G"
echo %var:~1%
Okay I have several lines in a text file. I want to get the first line and save it in another file. For example this is the text file:
put returns between paragraphs
for linebreak add 2 spaces at end
for linebreak add 2 spaces at end2
for linebreak add 2 spaces at end3
I want put returns between paragraphs to be saved into another file.
I used
for /f "tokens=" %%A in ('findstr /r "^[0-9][0-9]*$" <"C:\Users\Sherlock\Desktop\AbcImport\123.txt"') do echo 123>>1234.txt
pause
But it doesn't work at all.
How to get just the first line of a text file written into a new text file using a batch file?
Option 1 - SET /P : This is the simplest and fastest pure batch solution, provided the line does not exceed 1021 bytes, and it does not end with control characters that must be preserved. The size of the file does not matter - it will always read and write the first line very quickly.
#echo off
setlocal enableDelayedExpansion
set "ln="
<"input.txt" set /p "ln="
>"output.txt" (echo(!ln!)
Option 2 - FOR /F : This will work with lines up to ~8191 bytes long, but it can be slow if the file is really large because the FOR /F loop must read the entire file before it processes the first line. This solution is basically the same as the Mofi answer, except it disables the EOL option, so it never ignores the first line, regardless what the first character is. It does have a limitation that it will skip empty lines, so technically it does not give the correct result if the first line is empty:
#echo off
for /f usebackq^ delims^=^ eol^= %%A in ("input.txt") do echo(%%A>"output.txt"&goto :break
:break
There is a way to preserve the first line if it is empty using pure batch, but I would not bother. I would move on to ...
Option 3 - JREPL.BAT, or some other non-batch solution : Batch is quite poor at manipulating text files. You are much better off using some other scripting language like VBScript, JScript, or Powershell. Or a Windows port of any number of unix utilities.
I would use JREPL.BAT - a hybrid JScrpit/batch regular expression text processing utility that runs natively on any Windows machine from XP onward. It is way overkill for such a simple task, but it is an extremely handy, powerful, and efficient tool to have in your arsenal. Once you have it, then it can be used for many text processing tasks. Full documentation is embedded within the script.
jrepl "^.*" "$&" /jendln "quit=true" /f "input.txt" /o "output.txt"
Use CALL JREPL if you put the command within a batch script.
Here is the batch code to write just first non blank/empty line of a text file into another text file.
#echo off
for /F "usebackq delims=" %%I in ("InputTextFile.txt") do (
echo %%I>"OutputTextFile.txt"
goto ContinueAfterLoop
)
:ContinueAfterLoop
InputTextFile.txt is the file in current directory containing the first line to copy.
OutputTextFile.txt is the file created in current directory with first line from input file copied into this output file.
The command GOTO is used to exit the loop after first line is processed and continue the batch file below the loop.
For understanding the used commands and how they work, open a command prompt window, execute there the following commands, and read entirely all help pages displayed for each command very carefully.
echo /?
for /?
goto /?
Read also the Microsoft article about Using Command Redirection Operators.
You can use use this command:
SetLocal EnableDelayedExpansion
for /f "tokens=* delims=;" %%m in ("C:\Users\Sherlock\Desktop\AbcImport\123.txt") do (
set /p FirstLine=<%%m
echo !FirstLine!>>1234.txt
)
and for multiple file:
SetLocal EnableDelayedExpansion
for %%a in ("*") do (
for /f "tokens=* delims=;" %%m in ("%%a") do (
set /p FirstLine=<%%m
echo !FirstLine!>>1234.txt
)
)
rem Get the first line of a text file:
set /P "line=" < "C:\Users\Sherlock\Desktop\AbcImport\123.txt"
rem Write it into a new text file:
echo %line%> 1234.txt
I don’t know if this is possible but I would like to make a batch, which replaces all, the backslashes contained in a txt file (C:\locations) with forward slashes.
THX..
EDIT:
Im trying to loop:
set str1=!Var1!
echo.%str1%
set str1=%str1:\=/%
to work together with:
set file=C:\text1.txt
FOR /F %%i IN (%file%) DO (
set username=%%i
echo (load "%%i") >> C:\text.txt
)
what I have so far is:
ECHO Retreving list of files...
dir /s /b c:\ICT\AUTOCAD_2010\*.LSP > C:\BART1.txt
Echo Looping variables...
set file=C:\text1.txt
FOR /F %%1 IN (%file%) DO (
set fred=%%1
echo %%1 > C:\tempme.txt
)
set fred=C:\tempme.txt
set fred=%fred:\=/%
echo (load "%fred%") >> C:\text2.txt
however this returns:
(load "C:/tempme.txt")
which is incorect.
Windows' PowerSheel is too limited for that. I suggest you using a scripting language like Perl. Here's a quick script that does that:
my #file = <STDIN>;
my $text = join('', #file);
$text =~ s/\\/\//g;
print($text);
You can launch it like
perl foo.pl < example.txt > result.txt
Using sed as suggested by Tichodroma is another very good option.
I'm a little confused as to what you really want. Your sample code has a FOR ... IN that only has one file in the IN (), i.e. the content of %fred%. Then you write that one filename into a temporary file. Afterwards you have SET that replaces the backslash with a forward slash in the name of the temporary file. But this never touches any file.
However, in your opening segment you want to replace backslashes with forward slashes in a file. So I'm focusing on that part. That would be done this way:
#ECHO OFF
SETLOCAL EnableDelayedExpansion
REM Here's a backslash: \
FOR /F "delims=" %%a IN ('TYPE %0') DO (
SET line=%%a
ECHO !line:\=/!
)
Please note that for simplicity this little batch file parses itself (%0) and, therefore, only replaces that one backslash. However, feel free to put whichever file next to TYPE.
EnableDelayedExpansion makes the syntax with the ! work (see SET /? for more info about delayed expansion). TYPE obviously writes a file to the console. The FOR /F "delims=" now grabs the output of that line per line (since delims= defines no delimiter for the tokenizer of FOR). The line-variable is necessary, because I don't think that there is a proper way to make the ECHO-line work with %%a.
The only downside is that this will remove all empty lines from the original file. I don't know if that's a problem for you.
This question already has answers here:
Set output of a command as a variable (with pipes) [duplicate]
(6 answers)
Closed 7 years ago.
I need to run a simple find command and redirect the output to a variable in a Windows Batch File.
I have tried this:
set file=ls|find ".txt"
echo %file%
But it does not work.
If I run this command it works without problems:
set file=test.txt
echo %file%
So obviously my command output is not being set to my variable. Can anyone help? Thanks
I just find out how to use commands with pipes in it, here's my command (that extracts the head revision of an svn repo) :
SET SVN_INFO_CMD=svn info http://mySvnRepo/MyProjects
FOR /f "tokens=1 delims=" %%i IN ('%SVN_INFO_CMD% ^| find "Revision"') DO echo %%i
First of all, what you seem to expect from your question isn't even possible in UNIX shells. How should the shell know that ls|find foo is a command and test.txt is not? What to execute here? That's why UNIX shells have the backtick for such things. Anyway, I digress.
You can't set environment variables to multi-line strings from the shell. So we now have a problem because the output of ls wouldn't quite fit.
What you really want here, though, is a list of all text files, right? Depending on what you need it's very easy to do. The main part in all of these examples is the for loop, iterating over a set of files.
If you just need to do an action for every text file:
for %%i in (*.txt) do echo Doing something with "%%i"
This even works for file names with spaces and it won't erroneously catch files that just have a .txt in the middle of their name, such as foo.txt.bar. Just to point out that your approach isn't as pretty as you'd like it to be.
Anyway, if you want a list of files you can use a little trick to create arrays, or something like that:
setlocal enabledelayedexpansion
set N=0
for %%i in (*.txt) do (
set Files[!N!]=%%i
set /a N+=1
)
After this you will have a number of environment variables, named Files[0], Files[1], etc. each one containing a single file name. You can loop over that with
for /l %%x in (1,1,%N%) do echo.!Files[%%x]!
(Note that we output a superfluous new line here, we could remove that but takes one more line of code :-))
Then you can build a really long line of file names, if you wish. You might recognize the pattern:
setlocal enabledelayedexpansion
set Files=
for %%i in (*.txt) do set Files=!Files! "%%i"
Now we have a really long line with file names. Use it for whatever you wish. This is sometimes handy for passing a bunch of files to another program.
Keep in mind though, that the maximum line length for batch files is around 8190 characters. So that puts a limit on the number of things you can have in a single line. And yes, enumerating a whole bunch of files in a single line might overflow here.
Back to the original point, that batch files have no way of capturing a command output. Others have noted it before. You can use for /f for this purpose:
for /f %%i in ('dir /b') do ...
This will iterate over the lines returned by the command, tokenizing them along the way. Not quite as handy maybe as backticks but close enough and sufficient for most puposes.
By default the tokens are broken up at whitespace, so if you got a file name "Foo bar" then suddenly you would have only "Foo" in %%i and "bar" in %%j. It can be confusing and such things are the main reason why you don't ever want to use for /f just to get a file listing.
You can also use backticks instead of apostrophes if that clashes with some program arguments:
for /f "usebackq" %%i in (`echo I can write 'apostrophes'`) do ...
Note that this also tokenizes. There are some more options you can give. They are detailed in the help for command.
set command has /p option that tells it to read a value from standard input. Unfortunately, it does not support piping into it, but it supports reading a value from a first line of existing file.
So, to set your variable to the name of a first *.txt file, you could do the following:
dir /b *.txt > filename.tmp
set /p file=< filename.tmp
del /q filename.tmp
It is important not to add a space before or even after =.
P. S. No fors, no tokens.
Here's a batch file which will return the last item output by find:
#echo off
ls | find ".txt" > %temp%\temp.txt
for /f %%i in (%temp%\temp.txt) do set file=%%i
del %temp%\temp.txt
echo %file%
for has a syntax for parsing command output, for /f "usebackq", but it cannot handle pipes in the command, so I've redirected output to a temporary location.
I strongly recommend, given that you have access to ls, that you consider using a better batch language, such as bash or even an scripting language like python or ruby. Even bash would be a 20x improvement over cmd scripting.
The short answer is: Don't!
A windows shell env var can hold a max of 32 Kb and it isn't safe to save output from programs in them.
That's why you can't. In batch script you must adopt another programming style. If you need all of the output
from the program then save it to file. If you only need to check for certain properties then pipe the output into
a program that does the checking and use the errorlevel mechanism:
#echo off
type somefile.txt | find "somestring" >nul
if %errorlevel% EQU 1 echo Sorry, not found!
REM Alternatively:
if errorlevel 1 echo Sorry, not found!
However, it's more elegant to use the logical operators Perl style:
#echo off
(type somefile.txt | find "somestring" >nul) || echo Sorry, not found!
It's not available in DOS, but in the Windows console, there is the for command. Just type 'help for' at a command prompt to see all of the options. To set a single variable you can use this:
for /f %%i in ('find .txt') do set file=%%i
Note this will only work for the first line returned from 'find .txt' because windows only expands variable once by default. You'll have to enable delayed expansion as shown here.
what you are essentially doing is listing out .txt files. With that, you can use a for loop to over dir cmd
eg
for /f "tokens=*" %%i in ('dir /b *.txt') do set file=%%i
or if you prefer using your ls, there's no need to pipe to find.
for /f "tokens=*" %%i in ('ls *.txt') do set file=%%i
Example of setting a variable from command output:
FOR /F "usebackq" %%Z IN ( `C:\cygwin\bin\cygpath "C:\scripts\sample.sh"` ) DO SET BASH_SCRIPT=%%Z
c:\cygwin\bin\bash -c '. ~/.bashrc ; %BASH_SCRIPT%'
Also, note that if you want to test out the FOR command in a DOS shell, then you need only use %Z instead of %%Z, otherwise it will complain with the following error:
%%Z was unexpected at this time.