Format ‘ps’ command output without whitespace

This converts the first time to seconds:

ps -p $PROCID -o cputime,etimes | awk -F'[: ]+' '/:/ {t=$3+60*($2+60*$1); print t,$NF}'

As an example, the ps command produces:

$ ps -p 5403 -o cputime,etimes
    TIME ELAPSED
01:33:38 1128931

The awk command processes that and returns:

ps -p 5403 -o cputime,etimes | awk -F'[: ]+' '/:/ {t=$3+60*($2+60*$1); print t,$NF}'
5618 1128931

Explanation

• -F'[: ]+'

  This tells awk to treat both colons and spaces as field separators. This way, the hours, minutes, and seconds appear as separate fields.

• /:/ {t=$3+60*($2+60*$1); print t,$NF}

  The initial /:/ restricts the code to working only on lines that include a colon. This removes the header lines. The number of seconds is calculated from hours, minutes, seconds via t=$3+60*($2+60*$1). The resulting value for t is then printed along side with the elapsed time.

Handling days

If ps produces days,hours,minutes,seconds, as in:

2-03:01:33

Then, use this code instead:

ps -p $PROCID -o cputime,etimes | awk -F'[-: ]+' '/:/ {t=$4+60*($3+60*($2+24*$1)); print t,$NF}'

If days may or may not be prepended to the output, then use this combination command:

ps -p $PROCID -o cputime,etimes | awk -F'[-: ]+' '/:/ && NF==5 { t=$4+60*($3+60*($2+24*$1)); print t,$NF} /:/ && NF==4 {t=$3+60*($2+60*$1); print t,$NF}'

It seems to be a misleading error message.

If you look at the procps source, file common.h line 290:

extern unsigned        format_modifiers; /* -c -j -y -P -L... */

-j implied format_modifiers flag to be set, which cause the error if used with user defined output:

if(format_list){
  if(format_flags) return "Conflicting format options.";
  if(format_modifiers) return "Can't use output modifiers with user-defined output";
  if(thread_flags&TF_must_use) return "-L/-T with H/m/-m and -o/-O/o/O is nonsense";
  return NULL;
}

A message like Can't use output format modifiers with user-defined output would be better.

FreeBSD ps doesn't have this issue, -j option cause ps to print information about user, pid, ppid, pgid, sid, jobc, state, tt, time, and command. Adding -o makes the output aggregated:

$ ps -j -o ppid,sid
USER     PID PPID PGID  SID JOBC STAT TT     TIME COMMAND          PPID  SID
cuonglm 1196 1195 1196 1196    0 Ss    0  0:00.02 -sh (sh)         1195 1196
cuonglm 1233 1196 1233 1196    1 R+    0  0:00.00 ps -j -o ppid,si 1196 1196

Output modifiers control how information displayed, while output format controls control what information displayed.

Example the s options is an output format control, because it added process signal information to ps output:

$ ps s
  UID   PID          PENDING          BLOCKED          IGNORED           CAUGHT STAT TTY        TIME COMMAND
 1000 12831 0000000000000000 0000000000000002 0000000000384004 0000000188013003 Ss   pts/1      0:00 zsh
 1000 13067 0000000000000000 0000000000000000 0000000000000000 0000000073d3fef9 R+   pts/1      0:00 ps s

f is an output modifier, because it changed how the output displayed:

$ ps f
  PID TTY      STAT   TIME COMMAND
12831 pts/1    Ss     0:00 zsh
13238 pts/1    R+     0:00  \_ ps f

Here the output was displayed as hierarchy.