I noticed that cmd seems to accept some characters at the ends of commands. for example all of the following function correctly:
cls.
cls;
cls(
cls\
cls+
cls=
cls\"whatever"
cls\$
cls\#
and these do not:
cls'
cls$
cls)
cls-
cls#
cls\/
Does anybody know why this happens?
Thanks in advance.
It depends on the batch parser.
;,= are general batch delimiters, so you can append/prepend them to the most commands without effect.
;,,= ,=; echo hello
;,cls,;,,
The . dot can be appended to the most commands, as the parser will try to find a file named cls (without extension) cls.exe cls.bat, and when nothing is found then it takes the internal command.
The opening bracket is also a special charcter that the parser removes without error.
The \ backslash is used as path delimiter, so sometimes it works but sometimes you could change even the command.
cls\..\..\..\windows\system32\calc.exe
Related
I've been trying to write a function for my bash profile for quite some time now.
The problem I'm trying to overcome is I'm usually provided with file paths that include spaces and it's a pain having to go through and escape all the spaces before I try to open it up in terminal.
e.g.
File -> /Volumes/Company/Illustrators/Website Front Page Design.ai
What I'm trying to end up with is '/Volumes/Company/Illustrators/Website\ Front\ Page\ Design.ai' being opened from my terminal.
So far I've managed to escape the spaces out, but I then get the error "The file ..... does not exist."
My code so far is
function opn { open "${1// /\\ }";}
Any help would be very much appreciated.
The important thing to understand is the difference between syntax and literal data.
When done correctly, escaping is syntax: It's read and discarded by the shell. That is, when you run
open "File With Spaces"
or
open File\ With\ Spaces
or even
open File" "With\ Spaces
...the quoting and escaping is parsed and removed by the shell, and the actual operating system call that gets executed is this:
execv("/usr/bin/open", "open", "File With Spaces")
Note that there aren't any backslashes (or literal quotes) in that syscall's arguments! If you put literal backslashes in your data, then you cause this to be run:
/* this is C syntax, so "\\" is a single-character backslash literal */
execv("/usr/bin/open", "open", "File\\ With\\ Spaces")
...and unless there's a file with backslashes in its name, that just doesn't work, giving the "file does not exist" error you report.
So -- just call open with your name in quotes:
open "$1"
...there's no need for an opn wrappper.
Spaces are problematic in filenames because they're part of bash's default IFS (Internal Field Separator), which is used to separate tokens in a command line. That means that by default, when you use command an argument with spaces, the command will receive 4 arguments rather than 1 containing spaces.
I'm guessing you called your opn function in the same way, thus resulting in only the first part of your path as $1.
Hopefully, the fix is easy : enclose your path in quotes so that bash does not interpret the spaces. By using this, the need for your opn function disappears : open "/Volumes/Company/Illustrators/Website Front Page Design.ai" should work just fine.
This is killing me. I have a config file, "myconfig.cfg", with the following content:
SOME_VAR=2
echo "I LOVE THIS"
Then I have a script that I'm trying to run, that sources the config file in order to use the settings in there as variables. I can print them out fine, but when I try to put one into a numeric variable for use in something like a "seq " command, I get this weird "invalid arithmetic operator" error.
Here's the script:
#!/bin/bash
source ./myconfig.cfg
echo "SOME_VAR=${SOME_VAR}"
let someVarNum=${SOME_VAR}
echo "someVarNum=${someVarNum}"
And here's the output:
I LOVE THIS
SOME_VAR=2
")syntax error: invalid arithmetic operator (error token is "
someVarNum=
I've tried countless things that theoretically shouldn't make a difference, and, surprise, they don't. I simply can't figure it out. If I simply take the line "SOME_VAR=2" and put it directly into the script, everything's fine. I'm guessing I'll have to read in the config file line by line, split the strings by "=", and find+create the variables I want to use manually.
The error is precisely as indicated in a comment by #TomFenech. The first line (and possibly all the lines) in myconfig.cfg is terminated with a Windows CR-LF line ending. Bash considers CR to be an ordinary character (not whitespace), so it will set SOME_VAR to the two character string 2CR. (CR is the character with hex code 0x0D. You could see that if you display the file with a hex-dumper: hd myconfig.cfg.)
The let command performs arithmetic on numbers. It also considers the CR to be an ordinary character, but it is neither a digit nor an operator so it complains. Unfortunately, it does not make any attempt to sanitize the display of the character in the error message, so the carriage return is displayed between the two " symbols. Consequently, the end of the error message overwrites the beginning.
Don't create Unix files with a Windows text editor. Or use a utility like dos2unix to fix them once you copy them to the Unix machine.
I have a variable with a path, like this:
SET "somevar=D:\tree\path\nonsens\oink.txt"
And I have a file, where somethink like this is written
VAR=moresonsense
Now I want to replace the word morenonsense to D:\tree\path\nonsens\oink.txt. This should be the result
VAR=D:\tree\path\nonsens\oink.txt
For this, I am using the tool sed for windows. But using sed in windows gives me the following:
VAR=D: ree/path/nonsens/oink.txt
The spaces between the colon and ree is a tab. I thought, I could fix it with the following line before calling sed:
SET "somevar=%somevar:\\=\\\\%"
But no, this line is not working. So I have some questions:
Is there a possibility, to prevent sed from changing \t to a tab and prevent changing two backslashed \ to a slash /?
Is there another easy way to replace a string with another string within a file with BATCH?
Does someone has another idea how to resolve this problem?
You should not \-escape the \ instances in the variable expansion; use the following:
SET "somevar=%somevar:\=\\%"
I don't know whether that solves all your problems, but SET "somevar=%somevar:\\=\\\\%" definitely does not work as intended, because it'll only match two consecutive \ chars in the input, resulting in a no-op with your input.
I have the following command in a windows batch script
echo =%%k-16,INDIRECT.EXT^("'C:\Users\...\Analysis\[ObsStreamflow.xlsx]Sheet1'^!A%%k"^),INDIRECT.EXT^("'C:\Users\...\Analysis\[sim%%j.xlsx]Sheet1'^!B!val!"^),^=C%%k/1000,^=D%%k-B%%k,^=ABS^(E%%k^),^=(E%%k^)^^2,=^(B%%k-B10^),=Sqrt^(B%%k^),=SQRT^(D%%k^),=^(J%%k - B13^)^^2 >>t%%j.csv
where the omitted file path is 38 characters long (I don't think I'm hitting the line limits, but just in case this is the problem). This is a single line in my .bat file, shown here as multiple lines just to make things more readable.
The output is mostly correct, except that where I have ^^2, it just becomes 2 (so I have =(E1)2 and =(J1-B13)2. If I omit the Indirect.Ext text, and just have
echo =%%k-16,a1,b1,^=C%%k/1000,^=D%%k-B%%k,^=ABS^(E%%k^),^=(E%%k^)^^2,=^(B%%k-B10^),=Sqrt^(B%%k^),=SQRT^(D%%k^),=^(J%%k - B13^)^^2 >>t%%j.csv
it prints correctly, so the relevant comments show as =(E1)^2 and =(J1-B13)^2, which is what I am after.
I've not had any luck finding an answer, everything I have found just points to using ^^ to get echo to return ^. I cannot break this command into multiple lines, I need it to be a single row in csv format.
Any suggestions for a fix much appreciated, I only really need to use this for a week or so, don't need an elegant solution, just one that works. - I'm very new to bat scripts (and indeed programming in general), will keep trying different ideas in the mean time.
It's only the exclamation mark that creates the problems for you.
If at least one ! is in your line (and delayed expansion is enabled), then a second caret escape phase will be started.
In this phase quotes aren't regarded, only carets.
A small test
setlocal EnableDelayedExpansion
echo one^1
echo two^^2
echo two^^2 With exclam!
echo five^^^^^& With exclam!
Output
one1
two^2
two2 With exclam
four^& With exclam
So in your sample, you need five carets.
Four to create one caret and the last one to escape the ), as the escape of the special character is only once required.
Not sure what your specific problem is but you can use a trick in Windows to emulate echo -n (echo without a newline).
The commands:
<nul: >file.csv set /p junk=first field
<nul: >>file.csv set /p junk=,second field
>>file.csv echo ,third field
will result in a single line:
first field,second field,third field
That may make it easier for you to avoid the specific problem and, as a bonus, clean up your script so it's a little more readable (such as one field per script line).
It works because set /p var=prompt is the input command. It first outputs prompt without a newline then waits for the user to enter something, assigning it to the var environment variable.
By getting input from nul:, you basically give it an empty string so it doesn't wait. The prompt is output to file.csv without the newline.
In any case, for something this complex, I'd be bypassing cmd.exe for something a little more powerful such as the UNIX text processing tools under CygWin or MinGW (which require installation but are well worth it), or even VBScript scripts (which should be on Windows by default), where you can more easily control the output.
I got a useful tip from this post: https://stackoverflow.com/a/374363/151453 , but plagued by doskey's special characters.
(env: Windows 7 and Windows XP)
Using Visual C++ command line, we have env-vars INCLUDE and LIB. So with this doskey macro,
doskey whichinclude=for %i in ($1) do #echo.%~$INCLUDE:i
we can easily findout which .h is found first in which INCLUDE directory, really convenient.
However, this trick fails for LIB. I just CANNOT simply code a macro like:
doskey whichlib=for %i in ($1) do #echo.%~$LIB:i
Call whichlib winsock32.lib, it spouts The system cannot find the file specified.
I launch Procmon to know what happens, it reveals:
So I realize $L has special meaning for doskey, it is replaced with current drive letter when run.
Try double dollar( #echo.%~$$LIB:i ), still not working, Procmon report CMD accessing C:\echo .
Counld someone kindly help me out?
My doskey book mark: http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/doskey.mspx?mfr=true
I agree with Michael Burr's comment - you may be better off with a batch file. I generally do not use DOSKEY macros because they do not work within batch files, so it seems kind of pointless. In my mind, if a command works on the command line, it should also work within a batch file.
But... it is possible to do what you want :)
The $ only has special meaning if it is followed by a character that has special meaning to DOSKEY. The $L is interpreted as the < character (input redirection). The MS documentation implies that $$L should give a $L literal, but the documentation is not correct, as you have discovered.
The DOSKEY $ substitution happens before the normal command line parsing. The trick to embed a literal $L in your macro definition is to put an intervening character between $ and L that is not treated as special by DOSKEY, but that disappears during the normal command line parsing - The ^ works perfectly. $^ has no special meaning to DOSKEY, and ^L simply becomes L during command line parsing.
You can list the definition of your DOSKEY macros by using DOSKEY /M.
The full definition you require is whichlib=for %i in ($1) do #echo(%~$^LIB:i.
The ^ must be escaped when you define the macro. So the complete line to define the macro becomes:
doskey whichlib=for %i in ($1) do #echo(%~$^^LIB:i