I am working on a pexpect script that is running populating an output file name and then a prompt for the file's parameters.
The program that the script runs asks for Device: then Parameters: always on the same line.... so if the file path-name that is entered for Device is long, sometimes the Parameters prompt wraps to the next line.
My code looks like..
child.expect_exact('Device:')
child.sendline('/umcfiles/ftp_dir/ftp_peoplesoft/discount/AES_DISCOUNT_15010.TXT')
child.expect_exact('Parameters:')
This times out.. and here is what is in child.before
' /umcfiles/ftp_dir/ftp_peoplesoft/discount/AES_DISCOUNT_15010.TXT Param\r\neters: "RWSN" => '
so the expect fails... (a child.expect('Parameters:') also fails)
How can I ignore the \r\n if it is there, because depending on the length of the path/filename I am using it may not be there at all, or be in a different position.
Thanks!
Actually... I found a way to calculate how much is left on the given line, and dynamically set my expect to how much of the Parameter prompt should be visible... seems to be working
#look for end of line and fix how much of 'Parameters:' we look for in pexpect
dlen = 80-len('Device: /umcfiles/ftp_dir/ftp_peoplesoft/discount/AES_DISCOUNT_15010.TXT')
pstr='Parameters:'
if dlen > len(pstr):
dlen=len(pstr)
else:
dlen=dlen-3 #remove the /r/n
child.expect(pstr[0:dlen])
I am confused about the use of torch.CmdLine:text().
The documentation says the following:
text(string)
Logs a custom text message.
My understanding is that it adds some text message to the log file and the console. I just tried the sample code provided in the documentation page.
cmd = torch.CmdLine()
cmd:text()
cmd:text('Training a simple network')
cmd:text()
cmd:text('Options')
cmd:option('-seed',123,'initial random seed')
cmd:option('-booloption',false,'boolean option')
cmd:option('-stroption','mystring','string option')
cmd:text()
-- parse input params
params = cmd:parse(arg)
params.rundir = cmd:string('experiment', params, {dir=true})
paths.mkdir(params.rundir)
-- create log file
cmd:log(params.rundir .. '/log', params)
and I got the following output in command line and in the log file:
[program started on Sat Sep 10 14:55:30 2016]
[command line arguments]
stroption mystring
booloption false
seed 123
rundir experiment
[----------------------]
I am not seeing any output from calling text() method.
Could someone please help me in understanding what's happening here and the proper usage of text() method?
:text(string) method of CmdLine will only print string when the script is run with -help argument (and also when you decide to show help to user through its :help() method).
Example:
th MyScript.lua -help
In my Informix 4GL program, I have an input field where the user can insert a URL and the feed is later being sent over to the web via a script.
How can I validate the URL at the time of input, to ensure that it's a live link? Can I make a call and see if I get back any errors?
I4GL checking the URL
There is no built-in function to do that (URLs didn't exist when I4GL was invented, amongst other things).
If you can devise a C method to do that, you can arrange to call that method through the C interface. You'll write the method in native C, and then write an I4GL-callable C interface function using the normal rules. When you build the program with I4GL c-code, you'll link the extra C functions too. If you build the program with I4GL-RDS (p-code), you'll need to build a custom runner with the extra function(s) exposed. All of this is standard technique for I4GL.
In general terms, the C interface code you'll need will look vaguely like this:
#include <fglsys.h>
// Standard interface for I4GL-callable C functions
extern int i4gl_validate_url(int nargs);
// Using obsolescent interface functions
int i4gl_validate_url(int nargs)
{
if (nargs != 1)
fgl_fatal(__FILE__, __LINE__, -1318);
char url[4096];
popstring(url, sizeof(url));
int r = validate_url(url); // Your C function
retint(r);
return 1;
}
You can and should check the manuals but that code, using the 'old style' function names, should compile correctly. The code can be called in I4GL like this:
DEFINE url CHAR(256)
DEFINE rc INTEGER
LET url = "http://www.google.com/"
LET rc = i4gl_validate_url(url)
IF rc != 0 THEN
ERROR "Invalid URL"
ELSE
MESSAGE "URL is OK"
END IF
Or along those general lines. Exactly what values you return depends on your decisions about how to return a status from validate_url(). If need so be, you can return multiple values from the interface function (e.g. error number and text of error message). Etc. This is about the simplest possible design for calling some C code to validate a URL from within an I4GL program.
Modern C interface functions
The function names in the interface library were all changed in the mid-00's, though the old names still exist as macros. The old names were:
popstring(char *buffer, int buflen)
retint(int retval)
fgl_fatal(const char *file, int line, int errnum)
You can find the revised documentation at IBM Informix 4GL v7.50.xC3: Publication library in PDF in the 4GL Reference Manual, and you need Appendix C "Using C with IBM Informix 4GL".
The new names start ibm_lib4gl_:
ibm_libi4gl_popMInt()
ibm_libi4gl_popString()
As to the error reporting function, there is one — it exists — but I don't have access to documentation for it any more. It'll be in the fglsys.h header. It takes an error number as one argument; there's the file name and a line number as the other arguments. And it will, presumably, be ibm_lib4gl_… and there'll be probably be Fatal or perhaps fatal (or maybe Err or err) in the rest of the name.
I4GL running a script that checks the URL
Wouldn't it be easier to write a shell script to get the status code? That might work if I can return the status code or any existing results back to the program into a variable? Can I do that?
Quite possibly. If you want the contents of the URL as a string, though, you'll might end up wanting to call C. It is certainly worth thinking about whether calling a shell script from within I4GL is doable. If so, it will be a lot simpler (RUN "script", IIRC, where the literal string would probably be replaced by a built-up string containing the command and the URL). I believe there are file I/O functions in I4GL now, too, so if you can get the script to write a file (trivial), you can read the data from the file without needing custom C. For a long time, you needed custom C to do that.
I just need to validate the URL before storing it into the database. I was thinking about:
#!/bin/bash
read -p "URL to check: " url
if curl --output /dev/null --silent --head --fail "$url"; then
printf '%s\n' "$url exist"
else
printf '%s\n' "$url does not exist"
fi
but I just need the output instead of /dev/null to be into a variable. I believe the only option is to dump the output into a temp file and read from there.
Instead of having I4GL run the code to validate the URL, have I4GL run a script to validate the URL. Use the exit status of the script and dump the output of curl into /dev/null.
FUNCTION check_url(url)
DEFINE url VARCHAR(255)
DEFINE command_line VARCHAR(255)
DEFINE exit_status INTEGER
LET command_line = "check_url ", url
RUN command_line RETURNING exit_status
RETURN exit_status
END FUNCTION {check_url}
Your calling code can analyze exit_status to see whether it worked. A value of 0 indicates success; non-zero indicates a problem of some sort, which can be deemed 'URL does not work'.
Make sure the check_url script (a) exits with status zero on success and non-zero on any sort of failure, and (b) doesn't write anything to standard output (or standard error) by default. The writing to standard error or output will screw up screen layouts, etc, and you do not want that. (You can obviously have options to the script that enable standard output, or you can invoke the script with options to suppress standard output and standard error, or redirect the outputs to /dev/null; however, when used by the I4GL program, it should be silent.)
Your 'script' (check_url) could be as simple as:
#!/bin/bash
exec curl --output /dev/null --silent --head --fail "${1:-http://www.example.com/"
This passes the first argument to curl, or the non-existent example.com URL if no argument is given, and replaces itself with curl, which generates a zero/non-zero exit status as required. You might add 2>/dev/null to the end of the command line to ensure that error messages are not seen. (Note that it will be hell debugging this if anything goes wrong; make sure you've got provision for debugging.)
The exec is a minor optimization; you could omit it with almost no difference in result. (I could devise a scheme that would probably spot the difference; it involves signalling the curl process, though — kill -9 9999 or similar, where the 9999 is the PID of the curl process — and isn't of practical significance.)
Given that the script is just one line of code that invokes another program, it would be possible to embed all that in the I4GL program. However, having an external shell script (or Perl script, or …) has merits of flexibility; you can edit it to log attempts, for example, without changing the I4GL code at all. One more file to distribute, but better flexibility — keep a separate script, even though it could all be embedded in the I4GL.
As Jonathan said "URLs didn't exist when I4GL was invented, amongst other things". What you will find is that the products that have grown to superceed Informix-4gl such as FourJs Genero will cater for new technologies and other things invented after I4GL.
Using FourJs Genero, the code below will do what you are after using the Informix 4gl syntax you are familiar with
IMPORT com
MAIN
-- Should succeed and display 1
DISPLAY validate_url("http://www.google.com")
DISPLAY validate_url("http://www.4js.com/online_documentation/fjs-fgl-manual-html/index.html#c_fgl_nf.html") -- link to some of the features added to I4GL by Genero
-- Should fail and display 0
DISPLAY validate_url("http://www.google.com/testing")
DISPLAY validate_url("http://www.google2.com")
END MAIN
FUNCTION validate_url(url)
DEFINE url STRING
DEFINE req com.HttpRequest
DEFINE resp com.HttpResponse
-- Returns TRUE if http request to a URL returns 200
TRY
LET req = com.HttpRequest.create(url)
CALL req.doRequest()
LET resp = req.getResponse()
IF resp.getStatusCode() = 200 THEN
RETURN TRUE
END IF
-- May want to handle other HTTP status codes
CATCH
-- May want to capture case if not connected to internet etc
END TRY
RETURN FALSE
END FUNCTION
So I'm working with DrRacket and since I'm making a manual via #lang scribble for my procedures I'd like to put actual examples of my procedures running using #interactions So far I've got this part:
#lang scribble/manual
#(require (for-label racket))
#(require scribble/eval racket/sandbox)
#(define my-evaluator
(parameterize ([sandbox-output 'string]
[sandbox-error-output 'string])
(make-evaluator 'racket/base '(define (f) later) '(define later 5))))
And when I do
#interaction[#:eval my-evaluator]{
#(f)
}
and then I run scribble --htmls ++main-xref-in manual.scrbl it correctly renders as:
> (f)
5
Is there a way to use all my definitios (that are in a different file) to evaluate using scribble? I've tried changing the line 7 for :
(make-evaluator 'racket/base '(define (f) later) '(define later 5) #:require "mydefs.rkt")))
But when I try to render it, it throws something like this:
make-evaluator: bad requires: "mydefs.rkt"
I don't want to copy paste my definitions in the make-evaluator part (they're a lot!) any fix? Thank you racketeers!
asumu from IRC #racket helped me with this.
All I needed was to do this:
#(define my-evaluator
(parameterize ([sandbox-output 'string]
[sandbox-error-output 'string])
(make-base-eval #:lang 'racket '(define (f) later)
'(define later 5)
'(require "../man/manager.rkt"))))
Note that instead of using keywords I just quoted the require statement.
Using
#interaction[#:eval my-evaluator]{
#(define man (new manager%))#(send man crear-nodo '9)
}
Renders perfectly.
Thanks!
Say i have two files:
One is called mainFile.lua:
function altDoFile(name)
dofile(debug.getinfo(1).source:sub(debug.getinfo(1).source:find(".*\\")):sub(2)..name)
end
altDoFile("libs/caller.lua")
function callBack()
print "called back"
end
doCallback()
The other called caller.lua, located in a libs folder:
function doCallback()
print "performing call back"
_G["callBack"]()
end
The output of running the first file is then:
"performing call back"
Then nothing more, i'm missing a line!
Why is callBack never getting executed? is this intended behavior, and how do i get around it?
The fact that the function is getting called from string is important, so that can't be changed.
UPDATE:
I have tested it further, and the _G["callBack"] does resolve to a function (type()) but it still does not get called
Why not just use dofile?
It seems that the purpose of altDoFile is to replace the running script's filename with the script you want to call thereby creating an absolute path. In this case the path for caller.lua is a relative path so you shouldn't need to change anything for Lua to load the file.
Refactoring your code to this:
dofile("libs/caller.lua")
function callBack()
print "called back"
end
doCallback()
Seems to give the result you are looking for:
$ lua mainFile.lua
performing call back
called back
Just as a side note, altDoFile throws an error if the path does not contain a \ character. Windows uses the backslash for path names, but other operating systems like Linux and MacOS do not.
In my case running your script on Linux throws an error because string.find returns nill instead of an index.
lua: mainFile.lua:2: bad argument #1 to 'sub' (number expected, got nil)
If you need to know the working path of the main script, why not pass it as a command line argument:
C:\LuaFiles> lua mainFile.lua C:/LuaFiles
Then in Lua:
local working_path = arg[1] or '.'
dofile(working_path..'/libs/caller.lua')
If you just want to be able to walk back up one directory, you can also modify the loader
package.path = ";../?.lua" .. package.path;
So then you could run your file by doing:
require("caller")
dofile "../Untitled/SensorLib.lua" --use backpath librarys
Best Regards
K.