top,ps: improve /proc/PID/cmdinfo reading code

function                                             old     new   delta
display_status                                         -    1231   +1231
read_cmdline                                           -     101    +101
parse_conf                                          1284    1303     +19
arith                                               2033    2042      +9
collect_blk                                          467     474      +7
fsck_main                                           1909    1911      +2
dhcprelay_main                                      1125    1122      -3
singlemount                                         4555    4547      -8
read_close                                            50      36     -14
get_lcm                                              123     105     -18
ed_main                                             3111    3084     -27
func_args                                             73      28     -45
procps_scan                                          732     658     -74
top_main                                            2187     899   -1288
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 4/8 up/down: 1369/-1477)       Total: -108 bytes
   text    data     bss     dec     hex filename
 676048    2744   13968  692760   a9218 busybox_old
 675940    2744   13968  692652   a91ac busybox_unstripped

1 files changed, 9 insertions, 4 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 6a699a7e6..a95de848b 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -836,7 +836,7 @@ enum { COMM_LEN = 16 };
 typedef struct {
         DIR *dir;
 /* Fields are set to 0/NULL if failed to determine (or not requested) */
-        char *cmd;
+        /*char *cmd;*/
         char *argv0;
         /*char *exe;*/
         USE_SELINUX(char *context;)
@@ -852,7 +852,9 @@ typedef struct {
         unsigned gid;
         unsigned tty_major,tty_minor;
         char state[4];
-        /* basename of executable in exec(2), read from /proc/N/stat */
+        /* basename of executable in exec(2), read from /proc/N/stat
+         * (if executable is symlink or script, it is NOT replaced
+         * by link target or interpreter name) */
         char comm[COMM_LEN];
         /* user/group? - use passwd/group parsing functions */
 } procps_status_t;
@@ -863,9 +865,9 @@ enum {
         PSSCAN_SID      = 1 << 3,
         PSSCAN_UIDGID   = 1 << 4,
         PSSCAN_COMM     = 1 << 5,
-        PSSCAN_CMD      = 1 << 6,
+        /* PSSCAN_CMD      = 1 << 6, - use read_cmdline instead */
         PSSCAN_ARGV0    = 1 << 7,
-        PSSCAN_EXE      = 1 << 8, /* not implemented yet */
+        /* PSSCAN_EXE      = 1 << 8, - not implemented */
         PSSCAN_STATE    = 1 << 9,
         PSSCAN_VSZ      = 1 << 10,
         PSSCAN_RSS      = 1 << 11,
@@ -883,6 +885,9 @@ enum {
 procps_status_t* alloc_procps_scan(int flags);
 void free_procps_scan(procps_status_t* sp);
 procps_status_t* procps_scan(procps_status_t* sp, int flags);
+/* Format cmdline (up to col chars) into char buf[col+1] */
+/* Puts [comm] if cmdline is empty (-> process is a kernel thread) */
+void read_cmdline(char *buf, int col, unsigned pid, const char *comm);
 pid_t *find_pid_by_name(const char* procName);
 pid_t *pidlist_reverse(pid_t *pidList);