Can I head a file in tramp? - emacs

Say I want to tramp a remote file in Emacs. If the file is huge, this could take a long time.
Can I tell Emacs/Tramp to only head or display/retrieve part of it?

You can open the directory that the file is in, and type M-! head my_file. The command gets executed over SSH.
The function insert-file-contents takes optional arguments that specify which portion of the file to insert, and from a quick glance it seems like Tramp tries to extract only the parts it needs. You'd need to write an interactive function on top of that, though.

Related

mIRC Read command not performing

I am writing an mIRC script for a bot account to read a random line of text from a text file when a user keys in !read. As of now, when any user types !read, absolutely nothing happens. I have other commands set to work on TEXT commands, but this one seems to be the most puzzling, as I'm referencing a document rather than putting everything into the script itself.
on *:TEXT:!text:#: {
$read(C:\Program Files (x86)\mIRC\8Ball.txt,n)
}
My file is titled 8Ball.txt. What could be going wrong here?
Got it.
echo -a $read(C:\Users\Christopher\Desktop\8Ball.txt,n)
Changing the directory ended up doing it...it wasn't liking the location for some reason...I either blame me putting a / in front of echo, or I blame the space in Program Files (x86)
Your best move is to use the relative mIRC dir identifier $mircdir combing it with $qt which adds enclosing quotes.
$qt($+($mircdir,8Ball.txt))
Output:
"C:\Program Files (x86)\mIRC\8Ball.txt"
This way, you won't need to wonder why the script break when you changed the mIRC directory a year after.

Simple script to copy check and delete

I am brand new to scripts and would like to be able to write a script to copy a file (example.doc) from the source C:\Test to destination D:\Destination which checks that the copy has been successful and then deletes the original file.
A couple answers:
Research "move" (maybe, Google "batch files move"). The short documentation at the command prompt (move /?) doesn't specifically address whether it checks that the file arrived correctly before erasing the original, but it seems like a kinda obvious thing for the developers to do. There's probably someplace on the web that'll confirm whether they do that.
If that works, try "move C:\Test\example.doc D:\Destination". That'll probably do it.
Or, write a batch file, maybe mymove.bat
copy C:\Test\example.doc D:\Destination
if exist D:\Destination\example.doc del C:\Test\example.doc
You can get more elaborate: using a parameter to specify the file name, checking whether D:\Destination\example.doc and C:\Test\example.doc have the same size before you delete, using some switches to keep from getting prompted about things and similar. Maybe this'll get you started.
For all these batch file commands (move, copy, del, dir), you can get some good documentation for your particular operating system at the command prompt. Type <cmd> /? (like the move /? I mentioned above).
Batch file programming is tedious and frustrating, but it's available to all of us! Good luck.

zip recursively each file in a dir, where the name of the file has spaces in it

I am quite stuck; I need to compress the content of a folder, where I have multiple files (extension .dat). I went for shell scripting.
So far I told myself that is not that hard: I just need to recursively read the content of the dir, get the name of the file and zip it, using the name of the file itself.
This is what I wrote:
for i in *.dat; do zip $i".zip" $i; done
Now when I try it I get a weird behavior: each file is called like "12/23/2012 data102 test1.dat"; and when I run this sequence of commands; I see that zip instead of recognizing the whole file name, see each part of the string as single entity, causing the whole operation to fail.
I told myself that I was doing something wrong, and that the i variable was wrong; so I have replaced echo, instead than the zip command (to see which one was the output of the i variable); and the $i output is the full name of the file, not part of it.
I am totally clueless at this point about what is going on...if the variable i is read by zip it reads each single piece of the string, instead of the whole thing, while if I use echo to see the content of that variable it gets the correct output.
Do I have to pass the value of the filename to zip in a different way? Since it is the content of a variable passed as parameter I was assuming that it won't matter if the string is one or has spaces in it, and I can't find in the man page the answer (if there is any in there).
Anyone knows why do I get this behavior and how to fix it? Thanks!
You need to quote anything with spaces in it.
zip "$i.zip" "$i"
Generally speaking, any variable interpolation should have double quotes unless you specifically require the shell to split it into multiple tokens. The internal field separator $IFS defaults to space and tab, but you can change it to make the shell do word splitting on arbitrary separators. See any decent beginners' shell tutorial for a detailed account of the shell's quoting mechanisms.

How do I prevent emacs from resolving directory symlinks in paths?

I have a project, call it 'foobar', that when I checkout has all its source in the folder "foobar/foobar". Because the top level foobar directory contains nothing except for the inner foobar directory, it's pointless, but that's how things were originally checked into the project and it's outside my control. This has the unfortunate effect of making paths longer and harder to read, so I rename the toplevel foobar to "foobar-checkout" and then make a symlink called "foobar" that links to "foobar-checkout/foobar". This way I can open "foobar/source.c" instead of "foobar/foobar/source.c".
This works for when I'm in the shell, and when I first open the file in emacs, but after that emacs will resolve the symlink. So if I have source.c open and I press Ctrl+x Ctrl+f to open a new file, the path it lists is "foobar-checkout/foobar/" rather than "foobar/". Is there a way to get emacs to not resolve the symlink so I can enjoy the shorter path?
I've just tried this on GNU Emacs 22.2.1, and it doesn't seem to resolve my symlinks. Is it possible that the resolving of symlinks is not vanilla emacs behavior and is rather something unintentionally introduced with a file opening module, such as ffap.el?
Either way, I couldn't test my idea, but it occured to me that you might override file-symlink-p, described currently as:
file-symlink-p is a built-in function in `C source code'.
(file-symlink-p FILENAME)
Return non-nil if file FILENAME is the name of a symbolic link.
The value is the link target, as a string.
Otherwise it returns nil.
This function returns t when given the name of a symlink that
points to a nonexistent file.
If you modify that to always return nil, perhaps emacs won't resolve the symlinks:
(defun file-symlink-p (FILENAME)
nil)
Of course, this will probably break some other stuff, but maybe it's worth a shot.
You might like to use directory-abbrev-alist or maybe vc-follow-symlinks.

Emacs: Is there a way to generate a skeleton ChangeLog from diff?

I'd like to partly automate creation of GNU-style ChangeLog entries when working with source code in version control. The add-changelog-entry-other-window works with one file at a time and you have to visit the file to use it.
What I'd like to see instead is to have some command that would take an output of diff -u -p (or have integration with VC modes so it could process svn diff etc) and to create all the skeleton entries at once.
For example, if svn status shows
D file1.c
M file2.c
A file3.c
the command would create
2009-09-05 My Name <my.email>
* file1.c: Removed.
* file2.c: WRITE YOUR CHANGES HERE
* file3.c: New.
Better yet, if it could parse the changed files in some languages to an extent so it could offer:
* file2.c (new_function): New function.
(deleted_function): Removed.
(changed_function): WRITE YOUR CHANGES HERE
I have found this feature in Emacs manual, but I don't see how I could apply it here.
Any suggestions? Thanks.
EDIT: One answer suggested vc-update-change-log. Unfortunately it only supports CVS and it creates ChangeLog entries by querying the already-commited VC logs. Thus even if it supported svn and others, it would be impossible to commit the changes and the ChangeLog in the same commit.
EDIT2: Apparently add-changelog-entry-other-window (C-x 4 a) works not only from visited file but from diff hunk involving that file too. (Source) This is almost what I am looking for. This together with elisp loop to iterate through all hunks should solve it.
There is a function vc-update-change-log that automatically generates change log entries from the version control log entries.
diff-add-change-log-entries-other-window is documented to do exactly what you mentioned in EDIT2:
diff-add-change-log-entries-other-window is an interactive compiled
Lisp function in `diff-mode.el'.
(diff-add-change-log-entries-other-window)
Iterate through the current diff and create ChangeLog entries.
I.e. like `add-change-log-entry-other-window' but applied to all hunks.
Unfortunately, it doesn't work very well for, say, new files: it doesn't even include the filenames of such files in the skeletal changelog entry.
You might have better luck with gcc's mklog script, which you can get from http://gcc.gnu.org/viewcvs/gcc/trunk/contrib/mklog.
I don't know of a function that does this, but it should be easy to implement. Basically, you want to
get the changed files
for each file, call add-change-log
"Find change log file, and add an entry for today and an item for this file.
Optional arg WHOAMI (interactive prefix) non-nil means prompt for user
name and email (stored in `add-log-full-name' and `add-log-mailing-address').
Second arg FILE-NAME is file name of the change log.
If nil, use the value of `change-log-default-name'.
Third arg OTHER-WINDOW non-nil means visit in other window.
Fourth arg NEW-ENTRY non-nil means always create a new entry at the front;
never append to an existing entry. Option `add-log-keep-changes-together'
otherwise affects whether a new entry is created.
Option `add-log-always-start-new-record' non-nil means always create a
new record, even when the last record was made on the same date and by
the same person.
The change log file can start with a copyright notice and a copying
permission notice. The first blank line indicates the end of these
notices.
Today's date is calculated according to `add-log-time-zone-rule' if
non-nil, otherwise in local time."
so the magic code is going to look something like
(apply 'make-magic-change-log-entry changed-files-list)
and make-magic-change-log-entry simply curries the add-change-log function so that the only argument is file-name — you set the other ones.
I've written a function to do something similar to what you were talking about. You can get the code at http://www.emacswiki.org/emacs/log-edit-fill