How to invoke other programs in Racket? - lisp

I can successfully run pandoc in Windows CMD using the command:
pandoc test.md -o test.html
Then I want do the same in Racket, I tried:
(subprocess #f #f #f "pandoc" "test.md -o test.html")
and:
(shell-execute "pandoc" "" "test.md -o test.html" (current-directory) 'sw_showdefault)
But none of them gave me the expected .html file.
What is the correct way to do this? Thank you.

I agree with Joshua that it's hard to know how to answer your question as you originally asked it. Maybe you'll edit it. Meanwhile, to answer it as originally asked:
I think the equivalent of "typing it at the command prompt" in Racket would be system, or better system*.
(system "pandoc test.md -o test.html")

Related

Did `pwd` use to have a `-W` option?

I am reviewing the source code for gitflow-avh (A VirtualHome edition), version 1.12.3, which ships with Git for Windows, version 2.31.1. I'm looking at lines 67-73 of the script git-flow.
*MINGW*)
export GITFLOW_DIR=$(dirname "$(echo "$0" | sed -e 's,\\,/,g')")
pwd () {
builtin pwd -W
}
;;
*)
# The sed expression here replaces all backslashes by forward slashes.
# This helps our Windows users, while not bothering our Unix users.)
export GITFLOW_DIR=$(dirname "$(echo "$0" | sed -e 's,\\,/,g')")
;;
esac
What is the -W option? I'm only aware of -L and -P in bash. I'm fairly confident this is a "MINGW-ism", but I'm having trouble finding documentation online.
Does anyone know what the -W option does?
Ok, so I found this specifically has to do with MSYS2, as opposed to MINGW.
Per MSYS2's website, "How does MSYS2 differ from Cygwin?":
I had to run MSYS2 itself to actually see what the -W option provided:
In my "root" directory in Git Bash on Windows, pwd just gives me /.
But with -W, I get the real location:
$ pwd -W
C:/Program Files/Git
There's nothing on the man page for pwd, of course. Based on #A. Hendry's answer, I think I'll just alias pwd so that it always uses the -W option.

How can I get zsh to inherit the complete autocompletion?

I have an little shell script (named "run") which redirects all output of a program to /dev/null:
#!/bin/bash
$# &> /dev/null &
disown +
How can I say zsh that the whole autocompletion shall work for this?
I mean
$ run git com<TAB>
autocomplete to
$ run git commit
I was able to make that work by adding:
compdef _command run
to my .zshrc file.
I've based my answer on this bash question. It was worth giving it a try with compdef - surprisingly it worked.
As I'm still zsh/autocompletion newbie I cannot explain the inner workings and you should probably go through the documentation or other sources to find more on the topic.

run a prolog code with swipl in a command line

I am searching for swipl the similar feature as perl -e
In particular, I want to run prolog code in this fashion:
swipl --wanted-flag "fact(a). message:-writeln('hello')." -g "message" -t halt
This is possible to do with
swipl -f file -g "message" -t halt
where the prolog clauses are written in file
I am running swipl on the server side that takes user input as prolog clauses, therefore writing a file on the server is not a good idea.
One thing you can do is to use load_files/2 with the option stream, and load from standard input, not from an argument (you can still pass the entry point as an argument, I guess):
Say in a file fromstdin.pl you have:
main :-
load_files(stdin, [stream(user_input)]),
current_prolog_flag(argv, [Goal|_]),
call(Goal),
halt.
main :- halt(1).
and with this you can do:
$ echo 'message :- format("hello~n").' | swipl -q -t main fromstdin.pl -- message
|: hello
The comments by #false to this answer and the question will tell you what this |: is, if you are wondering, but if it annoys you, just do:
$ echo 'message :- format("hello~n").' \
| swipl -q -t main fromstdin.pl -- message \
| cat
hello
instead.
This will let you read any Prolog from standard input and call an arbitrary predicate from it. Whether this is a clever thing to do, I don't know. I would also not be surprised if there is a much easier way to achieve the same.

Bash: rewriting emacs command in bash_profile

I'm trying to write a command in my bash_profile to replace the default emacs command that will emacs a file if it exists, and if it doesn't exist, will copy a template to the new file and then emacs that.
What I attempted was:
function emacs()
{
if [ ! -f ${1} ]; then \
cp /FILEPATH/template.sh ${1}; fi;
builtin emacs ${1}
}
but the error I'm getting is "-bash: builtin: emacs: not a shell builtin"
How do I create a new function to replace the emacs command and then call the original emacs command within that function if emacs is not a builtin command?
You want command emacs, not builtin emacs. See help command.
As an aside, doesn't emacs have some sort of internal support for new-file templates? You might want to take a look at this: http://www.emacswiki.org/emacs/TemplatesMode. (Disclaimer: I don't use emacs; this was just one of the first pages I found while searching for "emacs new file template.)
(edit: sorry, command emacs in the other answer is better, use that.)
builtin only works for actual shell builtins like test, read, ...
Use the explicit path to emacs instead:
function emacs()
{
if [ ! -f ${1} ]; then \
cp /FILEPATH/template.sh ${1}; fi;
/usr/bin/emacs ${1}
}

lgrep and rgrep in Emacs

I am having problems with the greps in Emacs.
a) grep doesnt seem to understand the .[ch] for searching .c and .h files. This is a default option provided by Emacs with the lgrep command. The example is searching for the word "global" in .c/.h files.
grep -i -nH "global" *.[ch]
grep: *.[ch]: No such file or directory
Grep exited abnormally with code 2 at Mon Feb 16 19:34:36
Is this format not valid?
b) Using rgrep I get the following error:
find . "(" -path "*/CVS" -o -path "*/.svn" -o -path "*/{arch}" -o -path "*/.hg" -o -path "*/_darcs" -o -path "*/.git" -o -path "*/.bzr" ")" -prune -o -type f "(" -iname "*.[ch]" ")" -print0 | xargs -0 -e grep -i -nH "global"
FIND: Wrong parameter format
Grep finished (matches found) at Mon Feb 16 19:37:10
I am using Emacs 22.3.1 on Windows XP with the GNU W32 Utils (grep, find, xargs etc.). Grep v2.5.3 and find v4.2.20.
What am I missing?
UPDATE:
Too bad one can't accept multiple answers...since the solution to my problems are spread out.
grep -i -nH "global" *.c *.h
This solves the first problem. Thanks luapyad!
(setq find-program "c:\\path\\to\\gnuw32\\find.exe")
emacs was indeed using the Windows find.exe. Forcing the gnu32 find fixed the second problem. Thanks scottfrazer.
However, I still like ack best.
I found out that using:
(setq find-program "\"C:/path/to/GnuWin32/bin/find.exe\"")
(setq grep-program "\"C:/path/to/GnuWin32/bin/grep.exe\"")
Works better in windows, since you could have a space laying around the path and will screw up eventually.
Notice I used the two programs in my .emacs file.
Hope it's of some help to some other programmer in need ;)
Well, there is always Ack and Ack.el
For a) it looks like there are simply no .c or .h files in the current directory.
For b) Windows is trying to use its own find instead of the one from the GNU W32 Utils. Try:
(setq find-program "c:\\path\\to\\gnuw32\\find.exe")
Adam Rosenfield comment is worth expanding into an answer:
grep -r --include=\*.[ch] --exclude=\*{CVS,.svn,arch} -i -nH
To make the example given in this question work, use this:
grep -i -nH --include=\*.[ch] "global" *
It is also helpful to set the variable grep-command providing defaults to M-x grep:
(setq grep-command "grep -i -nH --include=\*.[ch] ")
Also here are some other useful command line parameters to grep:
-n print the line number
-s suppress error messages
-r recursive
I think the general problem is the windows cmd "shell" behaves very differently to a unix shell in respect to filename expansion regexps and wildcards.
To answer your (a) above try using:
grep -i -nH "global" *.c *.h
(You will still get an "invalid argument" if no *.c's or *.h's exist).
Or you can use command line option --include=\*.[ch] to make windows grep do "proper" filename pattern matching (see grep --help for other options)
I usually just use M-x grep and alter the command line args when prompted if I need to. But I just tried running M-x lgrep and got the same thing as you. It simply means that no files match *.[ch] in the current directory. You can customize the default options to include -r and search recursively through child directories as well:
M-x customize-group RET grep RET
Search for lgrep in that buffer to find/edit the Grep Template.
As far as M-x rgrep goes, I suspect it has something to do with the Windows version of find not liking the default options. That command works fine for me on Linux. Search for rgrep in that same customize buffer and tweak those options until the Windows find is happy.
Sorry I can't be more help with the Windows options, but I'm not familiar with them.