procps: shrink /proc scanning code a bit

function                                             old     new   delta
skip_fields                                           16      15      -1
.rodata                                           144266  144258      -8
procps_scan                                          739     692     -47
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-56)             Total: -56 bytes
   text    data     bss     dec     hex filename
 734845    3028   14400  752273   b7a91 busybox_old
 734789    3028   14400  752217   b7a59 busybox_unstripped

diff --git a/libbb/procps.c b/libbb/procps.c
index 9f5a4c0620d14d3145ca249779820197e31ee071..5924d60a84487a3eeaff058beec33ba8b72c6d06 100644 (file)
--- a/libbb/procps.c
+++ b/libbb/procps.c
@@ -109,9 +109,10 @@ void free_procps_scan(procps_status_t* sp)
 
 #if ENABLE_FEATURE_FAST_TOP
 /* We cut a lot of corners here for speed */
-static unsigned long fast_strtoul_10(char *str, char **endptr)
+static unsigned long fast_strtoul_10(char **endptr)
 {
        char c;
+       char *str = *endptr;
        unsigned long n = *str - '0';
 
        while ((c = *++str) != ' ')
@@ -123,7 +124,9 @@ static unsigned long fast_strtoul_10(char *str, char **endptr)
 static char *skip_fields(char *str, int count)
 {
        do {
-               str = skip_non_whitespace(str); str++;
+               while (*str++ != ' ')
+                       continue;
+               /* we found a space char, str points after it */
        } while (--count);
        return str;
 }
@@ -181,11 +184,11 @@ procps_status_t* procps_scan(procps_status_t* sp, int flags)
                }
 
                if (flags & PSSCAN_STAT) {
-                       char *cp;
+                       char *cp, *comm1;
+                       int tty;
 #if !ENABLE_FEATURE_FAST_TOP
                        unsigned long vsz, rss;
 #endif
-                       int tty;
 
                        /* see proc(5) for some details on this */
                        strcpy(filename_tail, "/stat");
@@ -193,12 +196,14 @@ procps_status_t* procps_scan(procps_status_t* sp, int flags)
                        if (n < 0)
                                break;
                        cp = strrchr(buf, ')'); /* split into "PID (cmd" and "<rest>" */
-                       if (!cp || cp[1] != ' ')
-                               break;
+                       /*if (!cp || cp[1] != ' ')
+                               break;*/
                        cp[0] = '\0';
                        if (sizeof(sp->comm) < 16)
                                BUG_comm_size();
-                       sscanf(buf, "%*s (%15c", sp->comm);
+                       comm1 = strchr(buf, '(');
+                       /*if (comm1)*/
+                               safe_strncpy(sp->comm, comm1 + 1, sizeof(sp->comm));
 
 #if !ENABLE_FEATURE_FAST_TOP
                        n = sscanf(cp+2,
@@ -231,20 +236,21 @@ procps_status_t* procps_scan(procps_status_t* sp, int flags)
 /* This costs ~100 bytes more but makes top faster by 20%
  * If you run 10000 processes, this may be important for you */
                        sp->state[0] = cp[2];
-                       sp->ppid = fast_strtoul_10(cp + 4, &cp);
-                       sp->pgid = fast_strtoul_10(cp, &cp);
-                       sp->sid = fast_strtoul_10(cp, &cp);
-                       tty = fast_strtoul_10(cp, &cp);
+                       cp += 4;
+                       sp->ppid = fast_strtoul_10(&cp);
+                       sp->pgid = fast_strtoul_10(&cp);
+                       sp->sid = fast_strtoul_10(&cp);
+                       tty = fast_strtoul_10(&cp);
                        sp->tty_major = (tty >> 8) & 0xfff;
                        sp->tty_minor = (tty & 0xff) | ((tty >> 12) & 0xfff00);
                        cp = skip_fields(cp, 6); /* tpgid, flags, min_flt, cmin_flt, maj_flt, cmaj_flt */
-                       sp->utime = fast_strtoul_10(cp, &cp);
-                       sp->stime = fast_strtoul_10(cp, &cp);
+                       sp->utime = fast_strtoul_10(&cp);
+                       sp->stime = fast_strtoul_10(&cp);
                        cp = skip_fields(cp, 3); /* cutime, cstime, priority */
-                       tasknice = fast_strtoul_10(cp, &cp);
+                       tasknice = fast_strtoul_10(&cp);
                        cp = skip_fields(cp, 3); /* timeout, it_real_value, start_time */
-                       sp->vsz = fast_strtoul_10(cp, &cp) >> 10; /* vsize is in bytes and we want kb */
-                       sp->rss = fast_strtoul_10(cp, &cp) >> 10;
+                       sp->vsz = fast_strtoul_10(&cp) >> 10; /* vsize is in bytes and we want kb */
+                       sp->rss = fast_strtoul_10(&cp) >> 10;
 #endif
 
                        if (sp->vsz == 0 && sp->state[0] != 'Z')