[PATCH] readserial: allow setting real time timestamps

[Vadim Bendebury (вб)]

Sometimes it is beneficial to attach real time stamps to console
output, for instance when there is a need to correlate two
independently captured logs.

This patch adds another command line option (-r,--realtime), when
given the generated log is printed with second's resolution real time
timestamps.

Signed-off-by: Vadim Bendebury 
---
 scripts/readserial.py | 44 +++++++++++++++++++++++++++-----------------
 1 file changed, 27 insertions(+), 17 deletions(-)

diff --git a/scripts/readserial.py b/scripts/readserial.py
index a7383e8..dc294eb 100755
--- a/scripts/readserial.py
+++ b/scripts/readserial.py
@@ -8,7 +8,7 @@
 # Usage:
 #   scripts/readserial.py /dev/ttyUSB0 115200

-import sys, os, time, select, optparse
+import datetime, sys, os, time, select, optparse

from python23compat import as_bytes

@@ -54,8 +54,10 @@ def calibrateserialread(infile, byteadjust):
             totalchars += len(d)
         lasttime = curtime

-def readserial(infile, logfile, byteadjust):
+def readserial(infile, logfile, byteadjust, real_time):
     lasttime = 0
+    isnewline = 0
+    charcount = 0
     while 1:
         # Read data
         try:
@@ -74,25 +76,29 @@ def readserial(infile, logfile, byteadjust):
             return 0
         datatime = time.time()

-        datatime -= len(d) * byteadjust
+        if not real_time:
+            datatime -= len(d) * byteadjust

-        # Reset start time if no data for some time
-        if datatime - lasttime > RESTARTINTERVAL:
-            starttime = datatime
-            charcount = 0
-            isnewline = 1
-            msg = "\n\n======= %s (adjust=%.1fus)\n" % (
-                time.asctime(time.localtime(datatime)), byteadjust * 1000000)
-            sys.stdout.write(msg)
-            logfile.write(as_bytes(msg))
-        lasttime = datatime
+            # Reset start time if no data for some time
+            if datatime - lasttime > RESTARTINTERVAL:
+                starttime = datatime
+                charcount = 0
+                isnewline = 1
+                msg = "\n\n======= %s (adjust=%.1fus)\n" % (
+                    time.asctime(time.localtime(datatime)),
byteadjust * 1000000)
+                sys.stdout.write(msg)
+                logfile.write(as_bytes(msg))
+            lasttime = datatime

# Translate unprintable chars; add timestamps
         out = as_bytes("")
         for c in d:
             if isnewline:
-                delta = datatime - starttime - (charcount * byteadjust)
-                out += "%06.3f: " % delta
+                if real_time:
+                    out += datetime.datetime.now().strftime('%H:%M:%S: ')
+                else:
+                    delta = datatime - starttime - (charcount * byteadjust)
+                    out += "%06.3f: " % delta
                 isnewline = 0
             oc = ord(c)
             charcount += 1
@@ -138,6 +144,10 @@ def main():
     opts.add_option("-t", "--time",
                     type="float", dest="time", default=None,
                     help="time to write one byte on serial port (in us)")
+    opts.add_option("-r", "--realtime",
+                    action="store_true", dest="realtime", default=False,
+                    help="print real time timestamps instead of deltas")
+
     options, args = opts.parse_args()
     serialport = 0
     baud = 115200
@@ -176,12 +186,12 @@ Or: apt-get install python-serial
     logname = time.strftime("seriallog-%Y%m%d_%H%M%S.log")
     f = open(logname, 'wb')
     if options.serial:
-        readserial(ser, f, byteadjust)
+        readserial(ser, f, byteadjust, options.realtime)
     else:
         # Read from a pipe
         while 1:
             ser = os.fdopen(os.open(serialport,
os.O_RDONLY|os.O_NONBLOCK), 'rb')
-            res = readserial(ser, f, byteadjust)
+            res = readserial(ser, f, byteadjust, options.realtime)
             ser.close()
             if res < 0:
                 break