A Few Questions About: libc

[scurtyParticipant]

I have a few questions in regards to the libc Module. I’m trying to covert a “libc.char_t *” (from returned from “libc.getenv()” ) to a String.

I know that a “libc.char_t *” is a pointer, so I tried just referencing it to maybe get a value, but I got a memory access error for some reason.

This seems to make sense to me but it’s obviously not valid. xD

Monkey

Local USERNAME:libc.char_t Ptr = libc.getenv("USER") Print(Cast<String>(USERNAME[0]))

1 2	Local USERNAME:libc.char_t Ptr = libc.getenv("USER") Print(Cast<String>(USERNAME[0]))

Error: Can’t convert “char_t” to a “String”
How would I get retrieve environment variables from libc?
Any help would be greatly appreciated. xD Thanks.

Edit: I’m currently getting this values from a simple

Monkey

libc.system("echo $USER > data.txt")

1	libc.system("echo $USER > data.txt")

[abakoboParticipant]

Mark just added String.FromChars a few days ago. It’s in the develop branch on github. I suppose it’s for that purpose..

https://github.com/blitz-research/monkey2/commit/b2976c674ad445a321b8f9c9c175c4025336b664

[scurtyParticipant]

That only seems to only convert an Array of Int’s to their to Unicode equivalents…

[codifiesParticipant]

Monkey

[crayon-5cba8b0ae4e95283956521 inline="true" ]#import "<libc>" Function Main() Local USERNAME:libc.char_t Ptr = libc.getenv("USER") Print(String.FromCString(USERNAME)) End

1 2 3 4 5

[crayon-5cba8b0ae4e95283956521 inline="true" ]#import "<libc>" Function Main() Local USERNAME:libc.char_t Ptr = libc.getenv("USER") Print(String.FromCString(USERNAME)) End

[/crayon]

[abakoboParticipant]

indeed…

There is the FromCString for that purpose..?

Monkey

[crayon-5cba8b0ae7096346344262 inline="true" ]#Import "<std>" Using std.. Function Main() Local USERNAME:= libc.getenv("USER") Local s:=String.FromCString(USERNAME) Print s End

1 2 3 4 5 6 7 8 9 10 11

[crayon-5cba8b0ae7096346344262 inline="true" ]#Import "<std>"   Using std..   Function Main()   Local USERNAME:= libc.getenv("USER") Local s:=String.FromCString(USERNAME) Print s End

[/crayon]

But the argument of get env is wrong:
Function getenv:char_t Ptr( name:@cstring )

So “USER” has to be converted to a cstring (don’t know what the @ means!)
from the docs:
monkey:monkey.types.String.ToCString
Method ToCString:Void( buf:Void Ptr, bufSize:Int )
Converts the string to a CString.

If there is enough room in the memory buffer, a null terminating ‘0’ is appended to the CString.
Parameters
buf Memory buffer to write the CString to.
bufSize Size of the memory buffer in bytes.

[scurtyParticipant]

Monkey

Local USERNAME:libc.char_t Ptr = libc.getenv("USERNAME") Print(String.FromCString(USERNAME))

1 2	Local USERNAME:libc.char_t Ptr = libc.getenv("USERNAME") Print(String.FromCString(USERNAME))

Sorry I didn’t realize I used the wrong Environment Variable to retrieve. I meant “USERNAME” xD

“String.FromCString” is what I need! Thanks so much!

[codifiesParticipant]

@scurty are you on windows ’cause USER works for me! whereas USERNAME does not…

maybe check both and see which one isn’t empty?

[scurtyParticipant]

USERNAME is for Linux. xD Sorry forgot to mention that. xD

[codifiesParticipant]

narp not here! its USER (Void Linux) let me reboot and see Antix (non systemd debian variant)… (brb)

Antix Linux also uses USER … NOT USERNAME

its login that sets the variable see also LOGNAME… just for extra confusion!

[scurtyParticipant]

I’ve always wanted to make my own Distro, and try and fix a few things I’ve noticed such as the Environment Vars. Pre-load it with a nice looking, light weight GUI(Openbox or XFCE/LXDE) with the some of the user-space written in mostly in Monkey2. No way I could do it myself. xD

Addition: I’m running the new Zorin OS 12 Core. And I don’t have a “USER” just a “USERNAME” and a “LOGNAME”
I’ll switch it to “LOGNAME” since both of our distros support it.

Monkey

Function GetEnv:String(value) Local variable:libc.char_t Ptr = libc.getenv(value) return String.FromCString(variable) End Function Function Main:Void() Print(GetEnv("LOGNAME")) End Function

1 2 3 4 5 6 7 8

Function GetEnv:String(value)     Local variable:libc.char_t Ptr = libc.getenv(value)     return String.FromCString(variable) End Function   Function Main:Void()     Print(GetEnv("LOGNAME")) End Function

[abakoboParticipant]

So “USER” has to be converted to a cstring

looks like it’s implicitly converting on this side

On Windows “USERNAME” is working..

Note that

Monkey

[crayon-5cba8b0af1bee290110532 inline="true" ] Local variable:libc.char_t Ptr = libc.getenv(value)

1 2 3

[crayon-5cba8b0af1bee290110532 inline="true" ] Local variable:libc.char_t Ptr = libc.getenv(value)

[/crayon]

can be declared simply by

Monkey

[crayon-5cba8b0af1bf3549486858 inline="true" ] Local variable:= libc.getenv(value)

1 2 3

[crayon-5cba8b0af1bf3549486858 inline="true" ] Local variable:= libc.getenv(value)

[/crayon]

[codifiesParticipant]

@scurty I love standards – there are so many to choose from… problem is what you fix others will probably consider broken…

@abakobo personally I’m not keep on implicit declarations – makes code less readable, explicit declaration might mean more typing but its worth it in the long run!

[scurtyParticipant]

Duplicate variables are in principle still not good. I just love K.I.S.S.

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