libprocstat/procstat.c

/*	libprocstat
	Copyright 2015-2022 Rivoreo

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or (at
	your option) any later version.

	This program is distributed in the hope that it will be useful, but
	WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
	General Public License for more details.
*/

#include "procstat.h"
#include "procstat-private.h"
#include <sys/param.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>

struct procstat_handle {
	const struct procstat_interface *interface;
	struct procstat_private_handle *handle;
};

extern const struct procstat_interface procstat_available_interfaces[];

/*
#if defined BSD || __FreeBSD_kernel__
#include "procstat.sysctl.c"
#elif defined __SVR4
#include "procstat.sysv.c"
#elif defined __linux__ || defined __CYGWIN__
#include "procstat.linux-procfs.c"
#elif defined __INTERIX
#include "procstat.interix.c"
#elif _WINDOWSNT_NATIVE
#include "procstat.nt.c"
#elif _WIN32
#include "procstat.windows.c"
#else
#error "Unsupported platform"
#endif

extern int _check[sizeof available_interfaces ? 1 : -1];
*/

struct procstat_handle *procstat_open() {
	unsigned int i;
	const struct procstat_interface *interface;
	struct procstat_private_handle *handle = NULL;
	struct procstat_handle *r = malloc(sizeof(struct procstat_handle));
	if(!r) return NULL;
	const char *interface_name = getenv("PROCSTAT_INTERFACE");
	if(interface_name && *interface_name) {
		//for(i = 0; i < sizeof available_interfaces / sizeof *available_interfaces; i++) {
		unsigned int i = 0;
		while(1) {
			interface = procstat_available_interfaces + i++;
			if(!interface->name) {
				fprintf(stderr, "procstat: requested interface '%s' not found\n",
					interface_name);
				break;
			}
			if(strcmp(interface->name, interface_name)) continue;
			handle = interface->open(r);
			if(!handle) {
				fprintf(stderr, "procstat: failed to open requested interface '%s'\n",
					interface_name);
				interface = NULL;
			}
			break;
		}
	}
	if(!handle) {
		unsigned int i = 0;
		do {
			interface = procstat_available_interfaces + i++;
			if(!interface->name) {
				int e = errno;
				free(r);
				errno = e;
				return NULL;
			}
			handle = interface->open(r);
		} while(!handle);
	}
	r->handle = handle;
	r->interface = interface;
	return r;
}

void procstat_close(struct procstat_handle *handle) {
	handle->interface->close(handle->handle);
	free(handle);
}

int procstat_get(struct procstat_handle *handle, pid_t pid, int flags, struct procstat *ps) {
	return handle->interface->get(handle->handle, pid, flags, ps);
}

int procstat_get_command_line(struct procstat_handle *handle, pid_t pid, char **command_line) {
	return handle->interface->get_command_line(handle->handle, pid, command_line);
}

int procstat_get_argv(struct procstat_handle *handle, pid_t pid, int *argc, char ***argv) {
	return handle->interface->get_argv(handle->handle, pid, argc, argv);
}

int procstat_get_path(struct procstat_handle *handle, pid_t pid, char **path) {
	return handle->interface->get_path(handle->handle, pid, path);
}

int procstat_get_mac_label(struct procstat_handle *handle, pid_t pid, char **label) {
	return handle->interface->get_mac_label(handle->handle, pid, label);
}

void procstat_walk(struct procstat_handle *handle, int walk_type, int flags, int (*func)(struct procstat_handle *, struct procstat *, void *), void *arg) {
	return handle->interface->walk(handle->handle, walk_type, flags, func, arg);
}