A feature request -- '-l 0:99:99', or custom profiles

[gf-mse]

Hi there -- thank you for a great program, it is an absolute joy to use!

Do you think it is possible to have a several atop aliases targeting disk activity, cpu etc, and save even more keystrokes? This would also make scripting in batch mode a bit easier.

In particular, when debugging disk-related issues, it is nice to have limitedlines() setting maxcpulines = 0, but keeping maxdsklines big.

If there were syntax like atop -l 0:99:99:.. to set these limits, or an option to have a custom rc file, one could make a few different atop aliases like atopd=atop -l 0:99:99:... or atopd=atop --rcfile=atoprc.disk ; I can see a quick and dirty way to have a custom rc file using an environment variable, but I'm not sure if that would go with the general style:

====
$ diff -u atop.c.2017-10-07 atop.c 
--- atop.c.2017-10-07	2017-10-07 22:25:26.079844329 +1100
+++ atop.c	2017-10-07 23:21:27.239578628 +1100
@@ -466,14 +466,32 @@
        */
        readrc("/etc/atoprc", 1);
 
-	if ( (p = getenv("HOME")) )
+        /* for local atoprc, p == NULL will mean "file not found" */
+        p = NULL ; /* NULL : no local rcfile */
+
+        /* try $ATOPRC first */
+	if ( (p = getenv("ATOPRC")) )
        {
-		char path[1024];
+                /* if we can read it -- let's read it */
+                if( access( p, R_OK ) != -1 ) {
+                        readrc(p, 0);
+                } else {
+                    /* if we can't -- let's try HOME next */
+                    p = NULL ;
+                }
+	}
+        
+        /* go for $HOME/.atoprc next */
+        if ( ( NULL == p ) ) {
+                if ( (p = getenv("HOME")) )
+                {
+                        char path[1024];
 
-		snprintf(path, sizeof path, "%s/.atoprc", p);
+                        snprintf(path, sizeof path, "%s/.atoprc", p);
 
-		readrc(path, 0);
-	}
+                        readrc(path, 0);
+                }
+        }
 
        /*
        ** check if we are supposed to behave as 'atopsar'
====