[freenos] r335 committed - Modified /bin/ps to use the new length modifiers....

From: codesite-noreply@xxxxxxxxxx
To: freenos@xxxxxxxxxxxxx
Date: Thu, 03 Sep 2009 22:55:28 +0000
Revision: 335
Author: nieklinnenbank
Date: Thu Sep  3 15:49:33 2009
Log: Modified /bin/ps to use the new length modifiers.
Additionally, lines are now printed using one printf(),
which results in much better performance.

http://code.google.com/p/freenos/source/detail?r=335

Modified:
 /trunk/bin/ps/Main.cpp

=======================================
--- /trunk/bin/ps/Main.cpp      Thu Jun 25 14:50:40 2009
+++ /trunk/bin/ps/Main.cpp      Thu Sep  3 15:49:33 2009
@@ -24,9 +24,9 @@
 #include <fcntl.h>
 #include <unistd.h>

-void outputf(char *fmt, ...)
-{
-    char path[128], buf[1025];
+void readfile(char *buf, Size size, char *fmt, ...)
+{
+    char path[128];
     int fd;
     Error e;
     va_list av;
@@ -36,9 +36,6 @@
     vsnprintf(path, sizeof(path), fmt, av);
     va_end(av);

-    /* Clear buffer. */
-    memset(buf, 0, sizeof(buf));
-
     /* Attempt to open the file first. */
     if ((fd = open(path, ZERO)) < 0)
     {
@@ -47,41 +44,36 @@
        exit(EXIT_FAILURE);
     }
     /* Read contents. */
-    while (1)
-    {
-       e = read(fd, buf, sizeof(buf) - 1);
-       switch (e)
-        {
-           /* Error occurred. */
-           case -1:
-               printf("Failed to read '%s': %s\r\n",
-                       path, strerror(errno));
-               close(fd);
-               exit(EXIT_FAILURE);
-
-           /* End of file. */
-           case 0:
-               close(fd);
-               return;
-
-           /* Print out results. */
-           default:
-               buf[e] = 0;
-               printf("%s", buf);
-               break;
-       }
-    }
-    /* Not reached. */
-    exit(EXIT_FAILURE);
+    switch ((e = read(fd, buf, size)))
+    {
+        /* Error occurred. */
+       case -1:
+           printf("Failed to read '%s': %s\r\n",
+                   path, strerror(errno));
+           close(fd);
+           exit(EXIT_FAILURE);
+
+       /* End of file. */
+       case 0:
+           close(fd);
+           return;
+
+       /* Success. */
+       default:
+           buf[e] = ZERO;
+           return;
+    }
 }

 int main(int argc, char **argv)
 {
     DIR *d;
     struct dirent *dent;
+    char status[11];
+    char cmdline[64];

     /* Print header. */
-    printf("PID STATUS CMD\r\n");
+    printf("PID   STATUS     CMD\r\n");

     /* Attempt to open the directory. */
     if (!(d = opendir("/proc")))
@@ -95,11 +87,15 @@
     {
        if (dent->d_name[0] != '.')
        {
-           printf("%s ", dent->d_name);
-           outputf("/proc/%s/status",  dent->d_name);
-           printf(" ");
-           outputf("/proc/%s/cmdline", dent->d_name);
-           printf("\r\n");
+           /* Read the process' status. */
+           readfile(status,  sizeof(status),
+                   "/proc/%s/status",  dent->d_name);
+           readfile(cmdline, sizeof(cmdline),
+                   "/proc/%s/cmdline", dent->d_name);
+
+           /* Output a line. */
+           printf("%5s %10s %32s\r\n",
+                   dent->d_name, status, cmdline);
        }
     }
     /* Close it. */
[freenos] r335 committed - Modified /bin/ps to use the new length modifiers....

Other related posts:
