I need to calculate the md5 sum of a file in Elixir, how can this be achieved?
I would expect that something like:
iex(15)> {:ok, f} = File.open "file"
{:ok, #PID<0.334.0>}
iex(16)> :crypto.hash(:md5, f)
** (ArgumentError) argument error
:erlang.iolist_to_binary(#PID<0.334.0>)
(crypto) crypto.erl:225: :crypto.hash/2
But clearly it doesn't work..
The documentation of Mix.Utils tells about read_path/2, but it didn't worked either.
iex(22)> Mix.Utils.read_path("file", [:sha512])
{:ok, "Elixir"} #the expected was {:checksum, "<checksum_value>"}
Is there any library that provides such functionality in a easy way?
In case anyone else finds this question and misses #FredtheMagicWonderDog's comment . . .
Check out this blog posting: http://www.cursingthedarkness.com/2015/04/how-to-get-hash-of-file-in-exilir.html
And here's the relevant code:
File.stream!("./known_hosts.txt",[],2048)
|> Enum.reduce(:crypto.hash_init(:sha256),fn(line, acc) -> :crypto.hash_update(acc,line) end )
|> :crypto.hash_final
|> Base.encode16
#=> "97368E46417DF00CB833C73457D2BE0509C9A404B255D4C70BBDC792D248B4A2"
NB: I'm posting this as community wiki. I'm not trying to get rep points; just trying to ensure the answer isn't buried in comments.
This also does the job:
iex(25)> {:ok, content} = File.read "file"
{:ok, "Elixir"}
iex(26)> :crypto.hash(:md5, content) |> Base.encode16
"A12EB062ECA9D1E6C69FCF8B603787C3"
The md5sum program on the same file returned:
$ md5sum file
a12eb062eca9d1e6c69fcf8b603787c3 file
I have used the information Ryan provided in the comments above, and added the Base.encode16 to reach the final result.
I don't know elixir, but in erlang proper, crypto:hash/2 takes iodata, which a file handle is not. You need to read the file and pass the content to hash(). If you know the file is fairly small, {ok, Content} = file:read_file("file") (or the elixir equivalent) would do the trick.
Besides the #aeliton solution is short and nifty, it has the best performance.
Related
Let's say I have two methods
"""
f(x::Integer)
Integer version of `f`.
"""
f(x::Integer) = println("I'm an integer!")
"""
f(x::Float64)
Float64 version of `f`.
"""
f(x::Float64) = println("I'm floating!")
and produce doc entries for those methods in my documentation using Documenter.jl's #autodocs or #docs.
How can I refer (with #ref) to one of the methods?
I'm searching for something like [integer version](#ref f(::Integer)) (which unfortunately does not work) rather than just [function f](#ref f) or [f](#ref).
Note that for generating the doc entries #docs has a similar feature. From the guide page:
[...] include the type in the signature with
```#docs
length(::T)
```
Thanks in advance.
x-ref: https://discourse.julialang.org/t/documenter-jl-ref-a-specific-method-of-a-function/8792
x-ref: https://github.com/JuliaDocs/Documenter.jl/issues/569#issuecomment-362760811
As pointed out by #mortenpi on Discourse and github:
You would normally refer to a function with [`f`](#ref), with the name
of the function being referred to between backticks in text part of
the link. You can then also refer to specific signatures, e.g. with
[`f(::Integer)`](#ref).
The #ref section in the docs should be updated to mention this
possibility.
When a line in my CSS file appears to be too long (typically a property followed by a bunch of values), I want to split them in to several new lines like this (sorry for my low reputation):
https://i.stack.imgur.com/bxXvv.png
But I have to manually enter spaces before the lines to achieve that. In reality, when I hit TAB with my cursor on the url line, what I get is this:
https://i.stack.imgur.com/r4nxa.png
The worst thing is that, after manually inserting the spaces, when I hit TAB again on the same line, it goes back to the ugly format due to indent-region.
This is not a significant issue but it really pains me and I really hope we can have a decent solution here. Thanks in advance!
M-x version:
GNU Emacs 25.1.1 (x86_64-apple-darwin16.1.0, NS appkit-1504.60 Version 10.12.1 (Build 16B2555)) of 2016-11-27
EDIT:
Also tried web-mode for css files and xah-css-mode. None of them worked out.
css-mode uses smie for indentation. It looks like the : in that scenario is tokenized as ":-property". One option would be changing the css-smie-rules to include another rule for indenting after that token.
Evaluating the following redefinition seems to give the indentation you want,
(defun css-smie-rules (kind token)
(pcase (cons kind token)
(`(:elem . basic) css-indent-offset)
(`(:elem . arg) 0)
(`(:list-intro . ,(or `";" `"")) t) ;"" stands for BOB (bug#15467).
(`(:before . "{")
(when (or (smie-rule-hanging-p) (smie-rule-bolp))
(smie-backward-sexp ";")
(smie-indent-virtual)))
(`(:before . ,(or "{" "("))
(if (smie-rule-hanging-p) (smie-rule-parent 0)))
;; *** Additional rule ***
(`(:after . ":-property") css-indent-offset)))
There is the command smie-config-show-indent that is useful to determine what indentation rules are being used at a given point.
#jenesaisquoi mentioned smie and provided an example which is really helpful. Here's my maybe-final solution to my own question.
Add these to the init.el file:
(require 'smie)
(defun css-smie-rules (kind token)
(pcase (cons kind token)
(`(:elem . basic) css-indent-offset)
(`(:elem . arg) 0)
(`(:list-intro . ,(or `";" `"")) t) ;"" stands for BOB (bug#15467).
(`(:before . "{")
(when (or (smie-rule-hanging-p) (smie-rule-bolp))
(smie-backward-sexp ";")
(smie-indent-virtual)))
(`(:before . ,(or "{" "("))
(if (smie-rule-hanging-p) (smie-rule-parent 0)))
;; *** Additional rules below ***
(`(:after . ":") css-indent-offset)
(`(:after . ",") css-indent-offset)))
The syntax is pretty self-explaining.
Maybe there are some ways to modify a function without re-writing it, but I'm not familiar with all the advice thing yet, so if I find a more elegant way I'll come back and edit.
Go to jenesaiquoi's answer for the best solution we can have now.
I've opened a issue for web-mode in Github, and the author of web-mode is now working on it. We will soon see an integrated support for the indentation I mentioned in the question.
I'm having issues when trying to read in a binary file I've previously written into another program. I have been able to open it and read it to an array with out compilation errors, however, the array is not populated (all 0's). Any suggestions or thoughts would be great. Here is the open/read statement I'm using:
allocate(dummy(imax,jmax))
open(unit=io, file=trim(input), form='binary', access='stream', &
iostat=ioer, status='old', action='READWRITE')
if(ioer/=0) then
print*, 'Cannot open file'
else
print*,'success opening file'
end if
read(unit=io, fmt=*, iostat=ioer) dummy
j=0
k=0
size: do j=1, imax
do k=1, jmax
if(dummy(j,k) > 0.) print*,dummy(j,k)
end do
end do size
Please let me know if you need more info.
Here is how the file is originally written:
out_file = trim(output_dir)//'SEVIRI_FRP_.08deg_'//trim(season)//'.bin'
print*, out_file
print*, i_max,' i_max,',j_max,' j_max'
open (io, file = out_file, access = 'direct', status = 'replace', recl = i_max*j_max*4)
write(io, rec = 1) sev_frp
write(io, rec = 2) count_sev_frp
write(io, rec = 3) sum_sev_frp
check: do n=1, i_max
inna: do m=1, j_max
!if (sev_frp(n,m) > 0) print*, count_sev_frp(n,m)
end do inna
end do check
print*,'n-',n,'m-',m
close(io)
First of all the form takes two possible values as far as I know: "FORMATTED" or "UNFORMATTED".
Second, to read, you should use a open that is symmetric to the open statement that you used to write the file, Unless you know exactely what you are doing. I suggest that for reading, you open with:
open(unit=io, file=trim(input), access='direct', &
iostat=ioer, status='old', action='READ', recl = i_max*j_max*4)
That corresponds to the open statement that you used to save the file.
As innoSPG says, you have a mismatch in the way the file is written and how it is read.
An external file may be connected with one of three access methods: sequential; direct; stream. Further, a connection may be formatted or unformatted.
When the file is opened for writing it uses the direct access method with unformatted records. The records are unformatted because this is the default (in the abscence of the form= specifier).
When you open the file for reading you use the non-standard extension of form="binary" and stream access. There is possibly nothing wrong with this, but it does require care.
However, with the read statements you are using formatted (list-directed) input. This will not be allowed.
The way suggested in the previous answer, of using a similar access method and record length will require a further change to the code. [You'll also need to set the value of the record length somehow.]
Not only will you need to remove the format, to match the unformatted records written, but you'll want to use the rec= specifier to access the records of the file.
Finally, if you are using the iostat= specifier you really should check the resulting value.
I am having troubles manipulating raw data. I am trying to change around a
resp_cookie in my ISAKMP header and when I do a sniff on the packet it is all in raw data format under Raw Load='\x00\x43\x01........... ' with about 3 lines like that. When I do a Wireshark capture I see the information I want to change but I cant seem to find a way to convert and change that raw data to find and replace the information I am looking for. Also, I can see the information I need when I do a hexdump(), but I can't store that in a variable. when I type i = hexdump(pkt) it spits out the hexdump but doesn't store the hexdump in i.
So this post is a little old, but I've come across it a dozen or so times trying to find the answer to a similar problem I'm having. I doubt OP has need for an answer anymore, but if anyone else is looking to do something similar...here you go!
I found the following code snippet somewhere in the deep, dark depths of google and it worked for my situation.
Hexdump(), show() and other methods of Scapy just output the packet to the terminal/console; they don't actually return a string or any other sort of object. So you need a way to intercept that data that it intends to write and put it in a variable to be manipulated.
NOTE: THIS IS PYTHON 3.X and SCAPY 3K
import io
import scapy
#generic scapy sniff
sniff(iface=interface,prn=parsePacket, filter=filter)
With the above sniff method, you're going to want to do the following.
def parsePacket(packet):
outputPacket = ''
#setup
qsave = sys.stdout
q = io.StringIO()
#CAPTURES OUTPUT
sys.stdout = q
#Text you're capturing
packet.show()
#restore original stdout
sys.stdout = qsave
#release output
sout = q.getvalue()
#Add to string (format if need be)
outputPacket += sout + '\n'
#Close IOStream
q.close()
#return your packet
return outputPacket
The string you return (outputPacket) can now be manipulated how you want.
Swap out .show() with whatever function you see fit.
P.S. Forgive me if this is a little rough from a Pythonic point of view...not a python dev by any stretch.
I'm trying to write a lua script that reads input from other processes and analyzes it. For this purpose I'm using io.popen and it works as expected in Windows, but on Unix(Solaris) reading from io.popen blocks, so the script just waits there until something comes along instead of returning immediately...
As far as I know I can't change the functionality of io.popen from within the script, and if at all possible I would rather not have to change the C code, because then the script will then need to be bound with the patched binary.
Does that leave me with any command-line solutions?
Ok got no answers so far, but for posterity if someone needs a similar solution I did the following more or less
function my_popen(name,cmd)
local process = {}
process.__proc = assert(io.popen(cmd..">"..name..".tmp", 'r'))
process.__file = assert(io.open(name..".tmp", 'r'))
process.lines = function(self)
return self.__file:lines()
end
process.close = function(self)
self.__proc:close()
self.__file:close()
end
return process
end
proc = my_popen("somename","some command")
while true
--do stuf
for line in proc:lines() do
print(line)
end
--do stuf
end
Your problems seems to be related to buffering. For some reason the pipe is waiting for some data to be read before it allows the opened program to write more to it, and it seems to be less than a line. What you can do is use io.popen(cmd):read"*a" to read everything. This should avoid the buffering problem. Then you can split the returned string in lines with for line in string.gmatch("[^\n]+") do someting_with(line) end.
Your solution consist in dumping the output of the process to a file, and reading that file. You can replace your use or io.popen with io.execute, and discard the return value (just check it's 0).