time: add -f format option compatible with GNU time

etc/mtree/BSD.tests.dist

@@ -1151,6 +1151,8 @@
         ..
         tar
         ..
+        time
+        ..
         touch
         ..
         tr

usr.bin/time/Makefile

@@ -1,5 +1,10 @@
 #	@(#)Makefile	8.1 (Berkeley) 6/6/93
 
+.include <src.opts.mk>
+
 PROG=	time
 
+HAS_TESTS=
+SUBDIR.${MK_TESTS}+= tests
+
 .include <bsd.prog.mk>

usr.bin/time/tests/Makefile

@@ -0,0 +1,4 @@
+PACKAGE=	tests
+ATF_TESTS_SH=	time_test
+
+.include <bsd.test.mk>

usr.bin/time/tests/time_test.sh

@@ -0,0 +1,171 @@
+#
+# Copyright (c) 2026 Lucas Holt
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+
+TIME=/usr/bin/time
+
+atf_test_case format_literal
+format_literal_head() {
+	atf_set descr "-f copies literal text and appends a newline"
+}
+format_literal_body() {
+	atf_check -s exit:0 -e inline:"hello world\n" \
+	    ${TIME} -f "hello world" true
+}
+
+atf_test_case format_percent
+format_percent_head() {
+	atf_set descr "-f prints %% as a single percent sign"
+}
+format_percent_body() {
+	atf_check -s exit:0 -e inline:"100%\n" \
+	    ${TIME} -f "100%%" true
+}
+
+atf_test_case format_backslash
+format_backslash_head() {
+	atf_set descr "-f expands \\t, \\n and \\\\"
+}
+format_backslash_body() {
+	printf 'a\tb\nc\\d\n' >expected
+	atf_check -s exit:0 -e file:expected \
+	    ${TIME} -f 'a\tb\nc\\d' true
+}
+
+atf_test_case format_unknown
+format_unknown_head() {
+	atf_set descr "-f prints unknown conversions as ?c"
+}
+format_unknown_body() {
+	atf_check -s exit:0 -e inline:"?q\n" \
+	    ${TIME} -f "%q" true
+}
+
+atf_test_case format_trailing
+format_trailing_head() {
+	atf_set descr "-f keeps a trailing % or backslash literal"
+}
+format_trailing_body() {
+	atf_check -s exit:0 -e inline:"x%\n" ${TIME} -f "x%" true
+	atf_check -s exit:0 -e inline:"x\\\\\n" ${TIME} -f 'x\' true
+}
+
+atf_test_case format_command
+format_command_head() {
+	atf_set descr "%C prints the command and its arguments"
+}
+format_command_body() {
+	atf_check -s exit:0 -e inline:"sh -c exit 0\n" \
+	    ${TIME} -f "%C" sh -c "exit 0"
+}
+
+atf_test_case format_exit_status
+format_exit_status_head() {
+	atf_set descr "%x prints the exit status of the command"
+}
+format_exit_status_body() {
+	atf_check -s exit:0 -e inline:"0\n" ${TIME} -f "%x" true
+	atf_check -s exit:3 -e inline:"3\n" ${TIME} -f "%x" sh -c "exit 3"
+}
+
+atf_test_case format_signal
+format_signal_head() {
+	atf_set descr "%x prints the signal number when the command is killed"
+}
+format_signal_body() {
+	atf_check -s signal:15 -e match:"^15$" \
+	    ${TIME} -f "%x" sh -c 'kill -TERM $$'
+}
+
+atf_test_case format_elapsed
+format_elapsed_head() {
+	atf_set descr "%e and %E report the elapsed time"
+}
+format_elapsed_body() {
+	atf_check -s exit:0 -e match:"^[1-9][.,][0-9][0-9]$" \
+	    ${TIME} -f "%e" sleep 1
+	atf_check -s exit:0 -e match:"^0:0[1-9][.,][0-9][0-9]$" \
+	    ${TIME} -f "%E" sleep 1
+	atf_check -s exit:0 -e match:"^0[.,][0-9][0-9]$" \
+	    ${TIME} -f "%e" true
+}
+
+atf_test_case format_numeric
+format_numeric_head() {
+	atf_set descr "numeric conversions produce numbers"
+}
+format_numeric_body() {
+	atf_check -s exit:0 \
+	    -e match:"^U=[0-9]+[.,][0-9]{2} S=[0-9]+[.,][0-9]{2} P=[0-9?]+%$" \
+	    ${TIME} -f "U=%U S=%S P=%P" true
+	atf_check -s exit:0 \
+	    -e match:"^M=[0-9]+ t=[0-9]+ K=[0-9]+ D=[0-9]+ p=[0-9]+ X=[0-9]+$" \
+	    ${TIME} -f "M=%M t=%t K=%K D=%D p=%p X=%X" true
+	atf_check -s exit:0 \
+	    -e match:"^F=[0-9]+ R=[0-9]+ W=[0-9]+ c=[0-9]+ w=[0-9]+$" \
+	    ${TIME} -f "F=%F R=%R W=%W c=%c w=%w" true
+	atf_check -s exit:0 \
+	    -e match:"^I=[0-9]+ O=[0-9]+ r=[0-9]+ s=[0-9]+ k=[0-9]+$" \
+	    ${TIME} -f "I=%I O=%O r=%r s=%s k=%k" true
+}
+
+atf_test_case format_pagesize
+format_pagesize_head() {
+	atf_set descr "%Z matches the system page size"
+}
+format_pagesize_body() {
+	pagesize=$(sysctl -n hw.pagesize)
+	atf_check -s exit:0 -e inline:"${pagesize}\n" ${TIME} -f "%Z" true
+}
+
+atf_test_case format_overrides
+format_overrides_head() {
+	atf_set descr "-f takes precedence over -p and -h, -l still appends"
+}
+format_overrides_body() {
+	atf_check -s exit:0 -e inline:"fmt\n" ${TIME} -p -f "fmt" true
+	atf_check -s exit:0 -e inline:"fmt\n" ${TIME} -h -f "fmt" true
+	atf_check -s exit:0 -e match:"^fmt$" \
+	    -e match:"maximum resident set size" \
+	    ${TIME} -l -f "fmt" true
+}
+
+atf_test_case format_output_file
+format_output_file_head() {
+	atf_set descr "-f output honours -o and -a"
+}
+format_output_file_body() {
+	atf_check -s exit:0 ${TIME} -o out.txt -f "first %x" true
+	atf_check -o inline:"first 0\n" cat out.txt
+	atf_check -s exit:0 ${TIME} -a -o out.txt -f "second %x" true
+	atf_check -o inline:"first 0\nsecond 0\n" cat out.txt
+	atf_check -s exit:0 ${TIME} -o out.txt -f "third %x" true
+	atf_check -o inline:"third 0\n" cat out.txt
+}
+
+atf_test_case format_missing_arg
+format_missing_arg_head() {
+	atf_set descr "-f without an argument is a usage error"
+}
+format_missing_arg_body() {
+	atf_check -s exit:1 -e match:"usage:" ${TIME} -f
+}
+
+atf_init_test_cases() {
+	atf_add_test_case format_literal
+	atf_add_test_case format_percent
+	atf_add_test_case format_backslash
+	atf_add_test_case format_unknown
+	atf_add_test_case format_trailing
+	atf_add_test_case format_command
+	atf_add_test_case format_exit_status
+	atf_add_test_case format_signal
+	atf_add_test_case format_elapsed
+	atf_add_test_case format_numeric
+	atf_add_test_case format_pagesize
+	atf_add_test_case format_overrides
+	atf_add_test_case format_output_file
+	atf_add_test_case format_missing_arg
+}

usr.bin/time/time.1

@@ -27,7 +27,7 @@
 .\"
 .\"     @(#)time.1	8.1 (Berkeley) 6/6/93
 .\"
-.Dd July 7, 2020
+.Dd September 8, 2026
 .Dt TIME 1
 .Os
 .Sh NAME
@@ -36,7 +36,7 @@
 .Sh SYNOPSIS
 .Nm
 .Op Fl al
-.Op Fl h | Fl p
+.Op Fl f Ar format | Fl h | Fl p
 .Op Fl o Ar file
 .Ar utility Op Ar argument ...
 .Sh DESCRIPTION
@@ -65,6 +65,107 @@ If the
 flag is used, append to the specified file rather than overwriting
 it.
 Otherwise, this option has no effect.
+.It Fl f Ar format
+Print the resource usage using
+.Ar format
+instead of the default output.
+The format string is copied to the output verbatim, with the following
+exceptions:
+a newline is appended,
+the sequences
+.Ql \et ,
+.Ql \en
+and
+.Ql \e\e
+produce a tab, a newline and a backslash respectively,
+and each
+.Ql %
+introduces a conversion described below.
+An unknown conversion is printed as a
+.Ql \&?
+followed by the offending character.
+The conversions are compatible with those of GNU
+.Nm ,
+so scripts written for it can be used unchanged.
+.Pp
+Time:
+.Bl -tag -width indent -compact
+.It Cm \&%E
+Elapsed real time, as
+.Ar minutes:seconds.hundredths ,
+or
+.Ar hours:minutes:seconds
+if the command ran for an hour or more.
+.It Cm \&%e
+Elapsed real time in seconds.
+.It Cm \&%S
+Total CPU seconds spent in kernel mode.
+.It Cm \&%U
+Total CPU seconds spent in user mode.
+.It Cm \&%P
+Percentage of the CPU this job got, computed as
+.Cm ( \&%U No + Cm \&%S ) No / Cm \&%e .
+.El
+.Pp
+Memory (all sizes are in kilobytes):
+.Bl -tag -width indent -compact
+.It Cm \&%M
+Maximum resident set size.
+.It Cm \&%t
+Average resident set size (unshared data).
+.It Cm \&%K
+Average total memory use (data, stack and text).
+.It Cm \&%D
+Average size of the unshared data and stack areas.
+.It Cm \&%p
+Average size of the unshared stack area.
+.It Cm \&%X
+Average size of the shared text area.
+.It Cm \&%Z
+The system page size, in bytes.
+.It Cm \&%F
+Number of major page faults.
+.It Cm \&%R
+Number of minor page faults (page reclaims).
+.It Cm \&%W
+Number of times the process was swapped out.
+.It Cm \&%c
+Number of involuntary context switches.
+.It Cm \&%w
+Number of voluntary context switches.
+.El
+.Pp
+I/O and miscellaneous:
+.Bl -tag -width indent -compact
+.It Cm \&%I
+Number of block input operations.
+.It Cm \&%O
+Number of block output operations.
+.It Cm \&%r
+Number of socket messages received.
+.It Cm \&%s
+Number of socket messages sent.
+.It Cm \&%k
+Number of signals delivered to the process.
+.It Cm \&%C
+The name and arguments of the command being timed.
+.It Cm \&%x
+The exit status of the command, or the number of the signal that
+terminated it.
+.It Cm \&%%
+A literal
+.Ql % .
+.El
+.Pp
+The
+.Fl f
+option takes precedence over
+.Fl h
+and
+.Fl p .
+The
+.Fl l
+output, if requested, follows the formatted line.
 .It Fl h
 Print times in a human friendly format.
 Times are printed in minutes, hours,
@@ -102,7 +203,7 @@ receives a
 (see the status argument for
 .Xr stty 1 )
 signal, the current time the given command is running will be written to the
-standard output.
+standard output in the default format.
 .Sh ENVIRONMENT
 The
 .Ev PATH
@@ -184,6 +285,14 @@ sys 0.00
          3  voluntary context switches
          0  involuntary context switches
 .Ed
+.Pp
+Print only the elapsed time and the peak memory use of a
+.Xr sort 1
+run, using a custom format:
+.Bd -literal -offset indent
+$ /usr/bin/time -f "%e seconds, %M KB max RSS, exit %x" sort -o /dev/null words
+0.12 seconds, 6740 KB max RSS, exit 0
+.Ed
 .Sh SEE ALSO
 .Xr builtin 1 ,
 .Xr csh 1 ,