strace: add a preset for ISO 8601 --absolute-timestamps formatesyr/long-options

* src/strace.c (parse_ts_arg) <enum>: Add FK_ISO.
(parse_ts_arg): Match "iso8601" and "iso" as FK_ISO format_kind.
(parse_ts_arg) <case FK_ISO>: Copy "%FT%T%z" to tflag_format.
(usage): Document it.
* doc/strace.1.in (.SS Output format): Likewise.
* NEWS: Mention it.
* tests/gen_tests.in (strace--absolute-timestamps-format-iso,
* strace--absolute-timestamps-format-iso-s,
* strace--absolute-timestamps-format-iso-ms,
* strace--absolute-timestamps-format-iso-us, strace--timestamps-iso-ns):
New tests.
* tests/options-syntax.test: Add new checks.
* tests/strace-tt.test: Escape "+" in the "date" output.

6 files changed, 26 insertions, 3 deletions

diff --git a/NEWS b/NEWS
index 5c95d4d27..721ba163b 100644
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,8 @@ Noteworthy changes in release ?.?? (????-??-??)
     SIGSYS siginfo_t).
   * Added ability to set arbitrary absolute timestamp formatting (using
     --absolute-timestamps=format:strftime=FORMAT option syntax).
+  * Added ability to set ISO 8601 time stamp format (using
+    --absolute-timestamps=format:iso8601 option syntax).
   * Implemented decoding of process_mrelease syscall, introduced in Linux 5.15.
   * Implemented decoding of SECCOMP_GET_NOTIF_SIZES operation of seccomp
     syscall.
diff --git a/doc/strace.1.in b/doc/strace.1.in
index b5f1dda1f..bfdf34640 100644
--- a/doc/strace.1.in
+++ b/doc/strace.1.in
@@ -986,6 +986,12 @@ Number of seconds since the epoch
 format string is
 .BR %s ).
 .TQ
+.BR iso8601 ", " iso
+Time stamp in ISO 8601 format
+.RB ( strftime (3)
+format string is
+.BR %FT%T%z ).
+.TQ
 .BR strftime = \fIfmt\fR
 Arbitrary
 .BR strftime (3)
diff --git a/src/strace.c b/src/strace.c
index 916b2295d..989d94678 100644
--- a/src/strace.c
+++ b/src/strace.c
@@ -394,7 +394,7 @@ Output format:\n\
                  limit length of print strings to STRSIZE chars (default %d)\n\
   --absolute-timestamps=[[format:]FORMAT[,[precision:]PRECISION]]\n\
                  set the format of absolute timestamps\n\
-     format:     none, time, unix, or strftime=STRING; default is time\n\
+     format:     none, time, unix, iso, or strftime=STRING; default is time\n\
      precision:  one of s, ms, us, ns; default is seconds\n\
   -t, --absolute-timestamps[=time]\n\
                  print absolute timestamp\n\
@@ -1841,6 +1841,7 @@ parse_ts_arg(const char *in_arg)
 		FK_NONE,
 		FK_TIME,
 		FK_UNIX,
+		FK_ISO,
 		FK_STRFTIME,
 	} format_kind = FK_UNSET;
 	int precision_width;
@@ -1873,6 +1874,10 @@ parse_ts_arg(const char *in_arg)
 			} else if (!strcasecmp(token, "unix")) {
 				format_kind = FK_UNIX;
 				continue;
+			} else if (!strcasecmp(token, "iso8601") ||
+				   !strcasecmp(token, "iso")) {
+				format_kind = FK_ISO;
+				continue;
 			} else if (!strncasecmp(token, strftime_pfx,
 						sizeof(strftime_pfx) - 1)) {
 				format_kind = FK_STRFTIME;
@@ -1910,6 +1915,9 @@ parse_ts_arg(const char *in_arg)
 	case FK_UNIX:
 		tflag_format = xstrdup("%s");
 		break;
+	case FK_ISO:
+		tflag_format = xstrdup("%FT%T%z");
+		break;
 	case FK_STRFTIME:
 		tflag_format = xstrdup(format_str);
 		break;
diff --git a/tests/gen_tests.in b/tests/gen_tests.in
index 00c930924..b5501589c 100644
--- a/tests/gen_tests.in
+++ b/tests/gen_tests.in
@@ -863,6 +863,10 @@ strace--absolute-timestamps-format-unix-precision-ms +strace-ttt.test 3 --absolu
 strace--absolute-timestamps-format-unix-precision-ns +strace-ttt.test 9 --absolute-timestamps=format:unix --absolute-timestamps=precision:ns
 strace--absolute-timestamps-format-unix-precision-s +strace-ttt.test 0 --absolute-timestamps=format:unix --absolute-timestamps=precision:s
 strace--absolute-timestamps-format-unix-precision-us +strace-ttt.test 6 --absolute-timestamps=precision:us --absolute-timestamps=format:unix
+strace--absolute-timestamps-format-iso +strace-tt.test 0 "%FT%T%z" "%FT%T%z" --absolute-timestamps=format:iso
+strace--absolute-timestamps-format-iso-ms +strace-tt.test 0 "%FT%T%z" "%FT%T\\.[[:digit:]]{3}%z" --absolute-timestamps=iso8601 --absolute-timestamps=precision:ms
+strace--absolute-timestamps-format-iso-s +strace-tt.test 0 "%FT%T%z" "%FT%T%z" --absolute-timestamps=precision:s --absolute-timestamps=iso
+strace--absolute-timestamps-format-iso-us +strace-tt.test 0 "%FT%T%z" "%FT%T\\.[[:digit:]]{6}%z" --timestamps=precision:us --absolute-timestamps=format:iso8601
 strace--follow-forks-output-separately +strace-ff.test --follow-forks --output-separately
 strace--relative-timestamps +strace-r.test --relative-timestamps
 strace--relative-timestamps-ms +strace-r.test --relative-timestamps=ms
@@ -878,6 +882,7 @@ strace--syscall-times-ns +strace-T.test --syscall-times=ns
 strace--syscall-times-s +strace-T.test --syscall-times=s
 strace--syscall-times-us +strace-T.test --syscall-times=us
 strace--timestamps +strace-t.test --timestamps
+strace--timestamps-iso-ns +strace-tt.test 0 "%FT%T%z" "%FT%T\\.[[:digit:]]{9}%z" --timestamps=iso --timestamps=ns
 strace--timestamps-time +strace-t.test --timestamps=time
 strace--timestamps-time-ms +strace-tt.test 3 "%T" "%T" --timestamps=time,ms
 strace--timestamps-time-ns +strace-tt.test 9 "%T" "%T" --timestamps=time,ns
diff --git a/tests/options-syntax.test b/tests/options-syntax.test
index b37819b5e..86cff2845 100755
--- a/tests/options-syntax.test
+++ b/tests/options-syntax.test
@@ -40,13 +40,15 @@ check_h "must have PROG [ARGS] or -p PID" --absolute-timestamps=s,
 check_h "must have PROG [ARGS] or -p PID" --absolute-timestamps=,,
 check_h "must have PROG [ARGS] or -p PID" --absolute-timestamps=s,,none
 check_h "must have PROG [ARGS] or -p PID" --timestamps=strftime=
-check_h "must have PROG [ARGS] or -p PID" --timestamps --absolute-timestamps=ns --timestamps=none --absolute-timestamps=format:time,precision:s --timestamps=ns,format:unix --absolute-timestamps=us,precision:ms,unix,precision:ns --timestamps=format:none,time,precision:us --absolute-timestamps=format:strftime=%r
+check_h "must have PROG [ARGS] or -p PID" --timestamps --absolute-timestamps=ns --timestamps=none --absolute-timestamps=format:time,precision:s --timestamps=ns,format:unix --absolute-timestamps=us,precision:ms,unix,precision:ns --timestamps=format:none,time,precision:us --absolute-timestamps=format:strftime=%r --timestamps=iso,iso8601,format:iso,format:iso8601
 check_h "invalid --absolute-timestamps argument: 'ss'" --absolute-timestamps=ss
 check_h "invalid --absolute-timestamps argument: 'strftime'" --absolute-timestamps=strftime
+check_h "invalid --absolute-timestamps argument: 'format:iso860'" --absolute-timestamps=format:iso860
 check_h "invalid --timestamps argument: 'format:s'" --timestamps=format:s
 check_h "invalid --timestamps argument: 's,non'" --timestamps=s,non
 check_h "invalid --timestamps argument: 'precision:strftime='" --timestamps=precision:strftime=
 check_h "invalid --timestamps argument: 'precision:none'" --timestamps=precision:none
+check_h "invalid --timestamps argument: 'precision:iso'" --timestamps=precision:iso
 check_e '-t and --absolute-timestamps cannot be provided simultaneously' -t --timestamps -p $$
 check_e '-t and --absolute-timestamps cannot be provided simultaneously' --absolute-timestamps -ttt -p $$
 check_e '-t and --absolute-timestamps cannot be provided simultaneously' -t --timestamps=ns -t -p $$
diff --git a/tests/strace-tt.test b/tests/strace-tt.test
index 150d0e43d..e79cd0bcb 100755
--- a/tests/strace-tt.test
+++ b/tests/strace-tt.test
@@ -28,7 +28,7 @@ s1="$(date +%s)"
 s="$s0"
 t_reg=
 while [ "$s" -le "$s1" ]; do
-	t="$(date "+${fmt_re}" --date "@$s")"
+	t="$(date "+${fmt_re}" --date "@$s" | sed 's/\(+\)/\\\1/')"
 	[ -z "$t_reg" ] && t_reg="$t" || t_reg="$t_reg|$t"
 	s=$(($s + 1))
 done