envp.h File Reference

Read environment variables without libc. More...

#include "common/platform/sys/syscall.h"

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Functions
const char *	wired_envp_get (int argc, char **argv, const char *name)
	Look up name in the environ block following argv.

Detailed Description

Read environment variables without libc.

wired_main receives only argc/argv, but a freestanding _start passes the kernel's initial stack through unchanged, so per the Linux ABI the NULL-terminated environ block sits right after argv: argv + argc + 1.

Function Documentation

wired_envp_get()

const char * wired_envp_get	(	int	argc,
		char **	argv,
		const char *	name )

Look up name in the environ block following argv.

Parameters

argc	argument count
argv	argument vector; argv[argc] is NULL and the environ block ("NAME=value" strings, NULL-terminated) follows it
name	NUL-terminated variable name without '=', e.g. "PROTOCOLS"

Returns

pointer to the NUL-terminated value (just past '='), which is the empty string for "NAME="; 0 when name is not present