[Xfce4-commits] <xfce4-taskmanager:master> Several micro fixes on the Linux implementation

[Mike Massonnet]

Updating branch refs/heads/master
         to e524915ac7ed98dcf0c08084711567e885f6024a (commit)
       from a7465b61f4a5eedc08d1a1223c2f32b86ad5fd0b (commit)

commit e524915ac7ed98dcf0c08084711567e885f6024a
Author: Mike Massonnet <mmassonnet at gmail.com>
Date:   Sat May 8 14:45:13 2010 +0200

    Several micro fixes on the Linux implementation
    
    Fix one segfault where some processes like “ls” live very briefly and
    those may be catched up but at the time to read the cmdline the process
    tree already disappeared. Also terminate the cmdline with \0.
    
    I ran the application on my netbook, which doesn't have /proc/<PID>/comm
    files... The code has been updated to read the short command from the
    buffer.

 src/task-manager-linux.c |   42 +++++++++++++++++++++++++-----------------
 1 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/src/task-manager-linux.c b/src/task-manager-linux.c
index f1aa1e9..6a5e2c0 100644
--- a/src/task-manager-linux.c
+++ b/src/task-manager-linux.c
@@ -107,7 +107,7 @@ static inline int get_pagesize ()
 	return pagesize;
 }
 
-static void
+static gboolean
 get_task_cmdline (Task *task)
 {
 	FILE *file;
@@ -116,11 +116,13 @@ get_task_cmdline (Task *task)
 	gchar c;
 
 	snprintf (filename, 96, "/proc/%i/cmdline", task->pid);
+	if ((file = fopen (filename, "r")) == NULL)
+		return FALSE;
 
-	/* Read byte per byte until EOF */
-	file = fopen (filename, "r");
+	/* Read full command byte per byte until EOF */
 	for (i = 0; (c = fgetc (file)) != EOF && i < sizeof (task->cmdline) - 1; i++)
 		task->cmdline[i] = (c == '\0') ? ' ' : c;
+	task->cmdline[i] = '\0';
 	if (task->cmdline[i-1] == ' ')
 		task->cmdline[i-1] = '\0';
 	fclose (file);
@@ -134,6 +136,8 @@ get_task_cmdline (Task *task)
 		task->cmdline[len+1] = ']';
 		task->cmdline[len+2] = '\0';
 	}
+
+	return TRUE;
 }
 
 static void
@@ -171,7 +175,6 @@ get_task_details (guint pid, Task *task)
 	FILE *file;
 	gchar filename[96];
 	gchar buffer[1024];
-	gchar *p1, *p2;
 
 	snprintf (filename, 96, "/proc/%d/stat", pid);
 	if ((file = fopen (filename, "r")) == NULL)
@@ -180,21 +183,25 @@ get_task_details (guint pid, Task *task)
 	fgets (buffer, 1024, file);
 	fclose (file);
 
-	/* Scanning the short process name is unreliable with scanf when it contains spaces */
-	p1 = g_strrstr (buffer, "(");
-	p2 = g_strrstr (buffer, ")");
-	while (p1 <= p2)
+	/* Scanning the short process name is unreliable with scanf when it contains
+	 * spaces, retrieve it manually and fill the buffer */
 	{
-		*p1 = 'x';
-		p1++;
+		gchar *p1, *po, *p2;
+		guint i = 0;
+		p1 = po = g_strstr_len (buffer, -1, "(");
+		p2 = g_strrstr (buffer, ")");
+		while (po <= p2)
+		{
+			if (po > p1 && po < p2)
+			{
+				task->name[i++] = *po;
+				task->name[i] = '\0';
+			}
+			*po = 'x';
+			po++;
+		}
 	}
 
-	/* Retrieve the short name from the comm file */
-	snprintf (filename, 96, "/proc/%d/comm", pid);
-	file = fopen (filename, "r");
-	fscanf (file, "%255s", task->name);
-	fclose (file);
-
 	/* Parse the stat file */
 	{
 		gchar dummy[256];
@@ -265,7 +272,8 @@ get_task_details (guint pid, Task *task)
 	}
 
 	/* Read the full command line */
-	get_task_cmdline (task);
+	if (!get_task_cmdline (task))
+		return FALSE;
 
 	return TRUE;
 }