Getting LOAD$(°) to load /proc/something

[rikky]

Somehow LOAD$ doesn't work in /proc
Not /proc/cpuinfo nor /proc/cmdline or /proc/consoles etc.
The rights for these files are -r--r--r--, owner:group root:root
I'm not root, but cat works.
And even if I turn myself in root, LOAD$ doesn't work.

I tested on a testfile with only read rights for everybody, and owner:group root:root
If this file is not in /proc, BaCon works.

SUB SUDO

 ALIAS getuid() TO GETUID

 IF GETUID != 0 THEN
   SYSTEM "sudo " & ARGUMENT$
   END RETVAL
 ELSE
   PRINT "you are now running as the root user "
 END IF

END SUB

IF GETUID != 0 THEN
 PRINT
 PRINT "cat works as a normal user:"
 PRINT "cat /proc/consoles => " & CHOP$(EXEC$("cat /proc/consoles"))
 PRINT
 PRINT "but not from BaCon:"
 PRINT "/proc/consoles => " & LOAD$("/proc/consoles")
 PRINT
END IF

SUDO

IF GETUID == 0 THEN
 PRINT
 PRINT "Even root is powerless:"
 PRINT "/proc/consoles => " & LOAD$("/proc/consoles")
 PRINT
END IF
response:

cat works as a normal user:
cat /proc/consoles => tty0                 -WU (EC p  )    4:7

but not from BaCon:
/proc/consoles =>

you are now running as the root user

Even root is powerless:
/proc/consoles =>

 Rik.

[Pjot]

Hi rikky,

Believe it or not, this makes perfectly sense. The Linux "proc" files are special files and created by the kernel. They have 0 byte size.

More details here: Linux Documentation Project

The BaCon function "LOAD$" uses the libc fread function. This function needs to specify how many bytes must be read from the disk. If the file is 0 bytes, then LOAD$ will load 0 bytes.

Instead, you must use the READLN function. This is not a bug, it is the same as you are programming in C directly.

This program works for me:

OPEN "/proc/cpuinfo" FOR READING AS proc

WHILE NOT(ENDFILE(proc))
   READLN txt$ FROM proc
   PRINT txt$
WEND

CLOSE FILE proc


HTH
Peter

[rikky]

Ow,,so.. 

Looking at your Linux documentation page the courage is sinking into my shoes.
Am I ever going to learn even one tenth of this?

Anyway, I adapted my bash4dummy's LOAD program, but now I'm bumping into the next error.

The program has OPTION EXPLICIT activated, and this option wants to have a TYPE for proc

This doesnt work:
GLOBAL proc TYPE FILE
OPEN argument$("1") FOR READING AS proc


How do you define a file? 

 Rik.

[Pjot]

Dear rikky,

You can use the C-type FILE* for this:

LOCAL proc TYPE FILE*

Regards,
Peter