procfs helper functions

We need these so we can create lash clients for liblash-less jack clients

lashd/Makefile.am

@@ -20,6 +20,7 @@ lashd_SOURCES = \
 	appdb.c appdb.h \
 	sigsegv.c sigsegv.h \
 	proctitle.c proctitle.h \
+	procfs.c procfs.h \
 	types.h \
 	$(top_srcdir)/common/safety.c
 

lashd/procfs.c

@@ -0,0 +1,127 @@
+/* -*- Mode: C ; indent-tabs-mode: t ; tab-width: 8 ; c-basic-offset: 8 -*- */
+/*
+ *   LASH
+ *
+ *   Copyright (C) 2009 Nedko Arnaudov <nedko@arnaudov.name>
+ *
+ *   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.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <assert.h>
+
+#include "procfs.h"
+#include "common/debug.h"
+
+static char g_buffer[4096];
+
+static
+char *
+procfs_get_process_file(
+	unsigned long long pid,
+	const char * filename)
+{
+	int fd;
+	ssize_t ret;
+	size_t max;
+	char * buffer_ptr;
+
+	sprintf(g_buffer, "/proc/%llu/%s", pid, filename);
+
+	fd = open(g_buffer, O_RDONLY);
+	if (fd == -1)
+	{
+		return NULL;
+	}
+
+	buffer_ptr = g_buffer;
+	do
+	{
+		max = sizeof(g_buffer) - (buffer_ptr - g_buffer);
+		ret = read(fd, buffer_ptr, max);
+		buffer_ptr += ret;
+	}
+	while (ret > 0);
+
+	if (ret == 0)
+	{
+		buffer_ptr = strdup(g_buffer);
+		lash_debug("process %llu %s is \"%s\"", pid, filename, buffer_ptr);
+	}
+	else
+	{
+		assert(ret == -1);
+		buffer_ptr = NULL;
+	}
+
+	close(fd);
+
+	return buffer_ptr;
+}
+
+static
+char *
+procfs_get_process_link(
+	unsigned long long pid,
+	const char * filename)
+{
+	int fd;
+	ssize_t ret;
+	char * buffer_ptr;
+
+	sprintf(g_buffer, "/proc/%llu/%s", pid, filename);
+
+	fd = open(g_buffer, O_RDONLY);
+	if (fd == -1)
+	{
+		return NULL;
+	}
+
+	ret = readlink(g_buffer, g_buffer, sizeof(g_buffer));
+	if (ret != 0)
+	{
+		g_buffer[ret] = 0;
+		buffer_ptr = strdup(g_buffer);
+		lash_debug("process %llu %s symlink points to \"%s\"", pid, filename, buffer_ptr);
+	}
+	else
+	{
+		assert(ret == -1);
+		buffer_ptr = NULL;
+	}
+
+	close(fd);
+
+	return buffer_ptr;
+}
+
+char *
+procfs_get_process_cmdline(
+	unsigned long long pid)
+{
+	return procfs_get_process_file(pid, "cmdline");
+}
+
+char *
+procfs_get_process_cwd(
+	unsigned long long pid)
+{
+	return procfs_get_process_link(pid, "cwd");
+}

lashd/procfs.h

@@ -0,0 +1,33 @@
+/* -*- Mode: C ; indent-tabs-mode: t ; tab-width: 8 ; c-basic-offset: 8 -*- */
+/*
+ *   LASH
+ *
+ *   Copyright (C) 2009 Nedko Arnaudov <nedko@arnaudov.name>
+ *
+ *   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.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef PROCFS_H__604D0D94_1609_4BB4_BFA7_5DC47830011A__INCLUDED
+#define PROCFS_H__604D0D94_1609_4BB4_BFA7_5DC47830011A__INCLUDED
+
+char *
+procfs_get_process_cmdline(
+	unsigned long long pid);
+
+char *
+procfs_get_process_cwd(
+	unsigned long long pid);
+
+#endif /* #ifndef PROCFS_H__604D0D94_1609_4BB4_BFA7_5DC47830011A__INCLUDED */