ps: conditionally support additional -o FIELDs

function                                             old     new   delta
procps_scan                                         1409    1642    +233
out_spec                                             220     300     +80
func_ruser                                             -      36     +36
func_rgroup                                            -      36     +36
func_group                                            13      49     +36
func_nice                                              -      29     +29
buffer_fill_and_print                                179     196     +17
send_tree                                            355     360      +5
mkfs_vfat_main                                      1604    1609      +5
display_speed                                         85      90      +5
scriptreplay_main                                    194     197      +3
find_out_spec                                         55      58      +3
changepath                                           192     195      +3
sha1_process_block64                                 497     484     -13
------------------------------------------------------------------------------
(add/remove: 3/0 grow/shrink: 10/1 up/down: 491/-13)          Total: 478 bytes

Signed-off-by: David Krakov <krakov@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 34 insertions, 7 deletions

diff --git a/procps/ps.c b/procps/ps.c
index b9a4aef15..4a6b60bdc 100644
--- a/procps/ps.c
+++ b/procps/ps.c
@@ -32,7 +32,7 @@ enum { MAX_WIDTH = 2*1024 };
 
 typedef struct {
         uint16_t width;
-        char name[6];
+        char name6[6];
         const char *header;
         void (*f)(char *buf, int size, const procps_status_t *ps);
         int ps_flags;
@@ -174,6 +174,11 @@ static void func_user(char *buf, int size, const procps_status_t *ps)
 #endif
 }
 
+static void func_group(char *buf, int size, const procps_status_t *ps)
+{
+        safe_strncpy(buf, get_cached_groupname(ps->gid), size+1);
+}
+
 static void func_comm(char *buf, int size, const procps_status_t *ps)
 {
         safe_strncpy(buf, ps->comm, size+1);
@@ -227,6 +232,26 @@ static void func_tty(char *buf, int size, const procps_status_t *ps)
                 snprintf(buf, size+1, "%u,%u", ps->tty_major, ps->tty_minor);
 }
 
+
+#if ENABLE_FEATURE_PS_ADDITIONAL_COLUMNS
+
+static void func_rgroup(char *buf, int size, const procps_status_t *ps)
+{
+        safe_strncpy(buf, get_cached_groupname(ps->rgid), size+1);
+}
+
+static void func_ruser(char *buf, int size, const procps_status_t *ps)
+{
+        safe_strncpy(buf, get_cached_username(ps->ruid), size+1);
+}
+
+static void func_nice(char *buf, int size, const procps_status_t *ps)
+{
+        sprintf(buf, "%*d", size, ps->niceness);
+}
+
+#endif /* FEATURE_PS_ADDITIONAL_COLUMNS */
+
 #if ENABLE_FEATURE_PS_TIME
 static void func_etime(char *buf, int size, const procps_status_t *ps)
 {
@@ -276,6 +301,7 @@ static void func_pcpu(char *buf, int size, const procps_status_t *ps)
 static const ps_out_t out_spec[] = {
 // Mandated by POSIX:
         { 8                  , "user"  ,"USER"   ,func_user  ,PSSCAN_UIDGID  },
+        { 8                  , "group" ,"GROUP"  ,func_group ,PSSCAN_UIDGID  },
         { 16                 , "comm"  ,"COMMAND",func_comm  ,PSSCAN_COMM    },
         { 256                , "args"  ,"COMMAND",func_args  ,PSSCAN_COMM    },
         { 5                  , "pid"   ,"PID"    ,func_pid   ,PSSCAN_PID     },
@@ -284,11 +310,12 @@ static const ps_out_t out_spec[] = {
 #if ENABLE_FEATURE_PS_TIME
         { sizeof("ELAPSED")-1, "etime" ,"ELAPSED",func_etime ,PSSCAN_START_TIME },
 #endif
-//      { sizeof("GROUP"  )-1, "group" ,"GROUP"  ,func_group ,PSSCAN_UIDGID  },
-//      { sizeof("NI"     )-1, "nice"  ,"NI"     ,func_nice  ,PSSCAN_        },
-//      { sizeof("%CPU"   )-1, "pcpu"  ,"%CPU"   ,func_pcpu  ,PSSCAN_        },
-//      { sizeof("RGROUP" )-1, "rgroup","RGROUP" ,func_rgroup,PSSCAN_UIDGID  },
-//      { sizeof("RUSER"  )-1, "ruser" ,"RUSER"  ,func_ruser ,PSSCAN_UIDGID  },
+#if ENABLE_FEATURE_PS_ADDITIONAL_COLUMNS
+        { 5                  , "nice"  ,"NI"     ,func_nice  ,PSSCAN_NICE    },
+        { 8                  , "rgroup","RGROUP" ,func_rgroup,PSSCAN_RUIDGID },
+        { 8                  , "ruser" ,"RUSER"  ,func_ruser ,PSSCAN_RUIDGID },
+//      { 5                  , "pcpu"  ,"%CPU"   ,func_pcpu  ,PSSCAN_        },
+#endif
 #if ENABLE_FEATURE_PS_TIME
         { 6                  , "time"  ,"TIME"   ,func_time  ,PSSCAN_STIME | PSSCAN_UTIME },
 #endif
@@ -311,7 +338,7 @@ static const ps_out_t* find_out_spec(const char *name)
 {
         unsigned i;
         for (i = 0; i < ARRAY_SIZE(out_spec); i++) {
-                if (!strcmp(name, out_spec[i].name))
+                if (!strncmp(name, out_spec[i].name6, 6))
                         return &out_spec[i];
         }
         bb_error_msg_and_die("bad -o argument '%s'", name);