This question seems to be (very) stupid be I can't deal with it :(
When I tried this batch code:
if "%1" == "-i" (
set is = %2
echo. %is%
shift
)
called with 2 (or more) arguments, it does NOT work. It actually prints a blank. The "shift" command is not done either. When I watch the executed code (without the #echo off at the beginning), I can see that the "set" command is completed.
What's wrong with it?
Example of calling:
c:\script.bat -i test -d bla
You have two issues. By default group of statements in parens will have variable expansion done all at once, that is before your set command. Also the semantics for set is wrong, you don't want spaces around the =.
Add this to the top of your file:
setlocal ENABLEDELAYEDEXPANSION
and remove the spaces around = in set:
set is=%2
Finally used delayed expansion:
echo. !is!
A possible third issue is you may need two SHIFTs, one for -i, one for it's is argument.
Update
Thanks to #dbenham for pointing out that it wasn't a syntax error with set, it's just surprising behavior that deserves a little explanation. If you execute these commands:
set a=one
echo "%a%"
The result is:
"one"
That makes sense, but try:
set b = two
echo "%b%"
And you get:
"%b%"
What? This is what you would expect when environment var b is unset. But we just set it. Or did we:
echo "%b %"
Displays:
" two"
For the Windows set command, unlike any other language or environment I'm aware of, the spaces are significant. The spaces before the = become part of the environment var name, spaces after become part of the value. This uncommon behavior is a common source of errors when writing Windows batch programs.
Related
This question is probably unnecessary as I probably have been searching for the wrong criteria. It's pretty easy I think but I just can't find the answer. I use batch files to automate installs with my work, setting folder permissions, copying files here, and there, silently running programs, removing old ones etc. The batch files contain lots of repetition and I want to tidy them up greatly for easier management. I have decided to set the repeated commands and copy folder locations as variables then use them instead. This is all fine but I'm adding the variables as a LIST which looks rubbish to me, I'm sure I can load them together in a sentence rather than a new line for each. Here's what I mean...
set dir1=md c:\newfolder
set killtask=taskkill /im someprog.exe /f >nul 2>&1
set config=echo F| XCOPY %~dp0configfile3.cfg /y C:\newfolder
And on and on...
So at the minute my batch now looks like this
JOB1
%dir1%
%killtask%
%config%
What I want to be able to do is have it like this (to reduce length if batch file etc.)
JOB1
%dir1% %killtask% %config%
(summary of my comments to the question):
Check your variables! Some chars like pipe (|) or redirection (>) change how the line is interpreted. Use this syntax to correct it:
set "killtask=taskkill /im someprog.exe /f >nul 2>&1"
(note the quotes and their position)
you can call several commands with &:
echo hello&echo world.
With your complex variables this would probably fail/work in an unexpected way. Try
(%dir1%)&(%killtask%)&(%config%)
so that the redirections and pipes stay at their intended commands.
Disclaimer: I'm not a batch files guru, just digging my way with the help of Google and SO. Also note that I'm trying to run this batch file as a Custom Action in SourceTree.
The following simple SET command doesn't seem to assign value to the variable:
SET MYVAR = %1
ECHO "%MYVAR%"
ECHO "!MYVAR!"
ECHO %1
The first ECHO above returns ""; the second one "!MYVAR!", whereas the last one returns the actual value of command-line parameter. How can I assign value to MVAR?
set is sensitive to spaces on each side of the =. You are setting a variable named myvar[Space}
I don’t understand the difference between:
set youtube=’https://youtube.com’
and
youtube=’https://youtube.com’
With the second one, I’m able to use it in the middle of a command, such as:
cygstart $youtube
and that works.
Why and how are these different? They both set variables?
And, when I don't use the word "set" I have to expand the variable using $?
Thanks.
The two commands are completely unrelated; set youtube='https://youtube.com' has nothing to do with $youtube. What it does is, it sets $1 to the whole string 'youtube=https://youtube.com'.
Per http://www.gnu.org/software/bash/manual/bashref.html#The-Set-Builtin, set is a shell builtin with three distinct purposes:
If you don't give it any options or arguments, it prints out all the existing shell variables and functions.
It has various options that let you change various properties of the shell. For example, set -C tells the shell that you don't want > to overwrite existing files (and that you instead want commands to fail if they would otherwise do that); and set +C tells the shell that never mind, you now want > to be able to overwrite files again.
Any arguments, other than options, replace the positional parameters ($1 and $2 and so on, as well as $# and $*).
Since set youtube='https://youtube.com' calls set with exactly one argument, namely youtube=https://youtube.com, it has the effect of setting the first positional parameter ($1) to youtube=https://youtube.com.
Note that youtube='https://youtube.com' is a somewhat misleading way to write youtube=https://youtube.com; the single-quotes aren't doing anything here (since the sole purpose of single-quotes is to escape whitespace and special characters, and https://youtube.com doesn't have any of these).
I'm just switch to zsh and now adapting the alias in which was printing some text (in color) along with a command.
I have been trying to use the $fg array var, but there is a side effect, all the command is printed before being executed.
The same occur if i'm just testing a echo with a color code in the terminal:
echo $fg_bold[blue] "test"
]2;echo "test" test #the test is in the right color
Why the command print itself before to do what it's supposed to do ? (I precise this doesn't happen when just printing whithout any wariable command)
Have I to set a specific option to zsh, use echo with a special parameter to get ride of that?
Execute the command first (keep its output somewhere), and then issue echo. The easiest way I can think of doing that would be:
echo $fg[red] `ls`
Edit: Ok, so your trouble is some trash before the actual output of echo. You have some funny configuration that is causing you trouble.
What to do (other than inspecting your configuration):
start a shell with zsh -f (it will skip any configuration), and then re-try the echo command: autoload colors; colors; echo $fg_bold[red] foo (this should show you that the problem is in your configuration).
Most likely your configuration defines a precmd function that gets executed before every command (which is failing in some way). Try which precmd. If that is not defined, try echo $precmd_functions (precmd_functions is an array of functions that get executed before every command). Knowing which is the code being executed would help you search for it in your configuration (which I assume you just took from someone else).
If I had to guess, I'd say you are using oh-my-zsh without knowing exactly what you turned on (which is an endless source of troubles like this).
I don't replicate your issue, which I think indicates that it's either an option (that I've set), or it's a zsh version issue:
$ echo $fg_bold[red] test
test
Because I can't replicate it, I'm sure there's an option to stop it happening for you. I do not know what that option is (I'm using heavily modified oh-my-zsh, and still haven't finished learning what all the zsh options do or are).
My suggestions:
You could try using print:
$ print $fg_bold[red] test
test
The print builtin has many more options than echo (see man zshbuiltins).
You should also:
Check what version zsh you're using.
Check what options (setopt) are enabled.
Check your ~/.zshrc (and other loaded files) to see what, if any, options and functions are being run.
This question may suggest checking what TERM you're using, but reading your question it sounds like you're only seeing this behaviour (echoing of the command after entry) when you're using aliases...?
for /f "tokens=*" %%a in ('find /v ":" "%appdata%\gamelauncher\options.txt" ^| find "menu=a"') do ( set usemenu=a )
for /f "tokens=*" %%a in ('find /v ":" "%appdata%\gamelauncher\options.txt" ^| find "menu=b"') do ( set usemenu=b )
for /f "tokens=*" %%a in ('find /v ":" "%appdata%\gamelauncher\options.txt" ^| find "menu=c"') do ( set usemenu=c )
Right, in this code (which may not work, that what i'm trying to find out) we have this "%%a" in that 'for' command.
First, whats the difference between %variable% and %%a?
Second, can someone explain the 'for' command to me? I have Google'd it way too much and all the explanations seem way to complicated...
What I am trying to do is pull a variable from options.txt, so i can change the menu style of my game launcher. there are 3 styles (a, b and c), so if the options.txt reads "menu=a" how can i get it to set a variable like %usemenu% to the value of a?
Thanks for any help in advance!
%variable% are environment variables. They are set with set and can be accessed with %foo% or !foo! (with delayed expansion if enabled). %%a are special variables created by the for command to represent the current loop item or a token of a current line.
for is probably about the most complicated and powerful part of batch files. If you need loop, then in most cases for has you covered. help for has a summary.
You can
iterate over files: for %x in (*.txt) do ...
repeat something n times: for /l %x in (1, 1, 15) do... (the arguments are start, step and end)
iterate over a set of values: for %x in (a, b, c) do ...
iterate over the lines of a file: for /f %x in (foo.txt) do ...
tokenize lines of a file: for /f "tokens=2,3* delims=," %x in (foo.txt) do ...
iterate over the output of a command: for /f %x in ('somecommand.exe') do ...
That's just a short overview. It gets more complex but please read the help for that.
Variables of the form %%a (or %a if for is used outside of batch files) are very similar to arguments to batch files and subroutines (%1, %2, ...). Some kinds of expansions can be applied to them, for example to get just the file name and extension if the variable represents a file name with path you can use %%~nxa. A complete overview of those is given in help for.
On the other hand, environment variables have other kinds of special things. You can perform replacements in them via %foo:a=b% would result in %foo% except that every a is replaced by a b. Also you can take substrings: %foo:~4,2%. Descriptions of those things can be found in help set.
As to why %variables% and %%a are different things that's a bit hard to answer and probably just a historical oddity. As outlined above there is a third kind of variable, %1, etc. which are very similar to those used in for and have existed for longer, I guess. Since environment variables are a bit unwieldy to use in for due to blocks and thus heavy reliance on delayed expansion the decision probably was made to use the same mechanisms as for arguments instead of environment variables.
Also environment variables could be more expensive, given that the process has a special “environment” block of memory where they are stored in variable=value␀ pairs, so updating environment variables involves potentially copying around a bit of memory while the other kind of variables could be more lightweight. This is speculation, though.
As for your problem, you don't really need for here:
find /v ":" "%appdata%\gamelauncher\options.txt" | find "menu=a" && set usemenu=a
This will only run the set if the preceding command was successful, i.e. menu=a was found. This should be considerably easier than for. From what I read you're trying to look whether menu=a exists in a line that does not contain a colon and in that case usemenu should be set to a, right? (And likewise for b and c. You could try coaxing for into doing that by looping over the lines of the file or output and tokenizing appropriately to figure out the value of menu but depending on the format of the lines this can be tricky. If what you have there works in theory then you should simply stick to that. You can however use a loop around it to avoid having to repeat the same line three times for a, b and c:
for %%X in (a b c) do (
find /v ":" "%appdata%\gamelauncher\options.txt" | find "menu=%%X" && set usemenu=%%X
)
If the file you are parsing is simple, however, with just name=value pairs in each line where : foo would be a comment, then you could use for as well:
for /f "tokens=1,* eol=: delims==" %%A in (%appdata%\gamelauncher\options.txt) do (
if "%%A"=="menu" set usemenu=%%B
)
But that depends a little on the exact format of the file. Above snippet would now read the file line by line and for each line would discard everything after a colon (the eol=: option), use the equals sign as a token delimiter and capture two tokens: The part before the first = and everything after it. The tokens are named starting with %%A so the second one is implicitly %%B (again, this is explained in help for). Now, for each line we examine the first token and look whether it's menu and if so, assign its value to the usemenu variable. If you have a lot of possible options to support this is certainly easier to maintain :-).