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CANDUMP(1) User Commands CANDUMP(1)


candump - manual page for candump 2020.11.0-1


candump [options] <CAN interface>+


candump - dump CAN bus traffic.

(use CTRL-C to terminate candump)


(timestamp: (a)bsolute/(d)elta/(z)ero/(A)bsolute w date)
(read hardware timestamps instead of system timestamps)
(increment color mode level)
(binary output - may exceed 80 chars/line)
(enable additional ASCII output)
(swap byte order in printed CAN data[] - marked with '`' )
(silent mode - 0: off (default) 1: animation 2: silent)
(log CAN-frames into file. Sets '-s 2' by default)
(use log file format on stdout)
(terminate after reception of <count> CAN frames)
(set socket receive buffer to <size>)
(Don't exit if a "detected" can device goes down.
(monitor dropped CAN frames)
(dump CAN error frames in human-readable format)
(print extra message infos, rx/tx brs esi)
(terminate after <msecs> without any reception)

Up to 16 CAN interfaces with optional filter sets can be specified on the commandline in the form: <ifname>[,filter]*


Comma separated filters can be specified for each given CAN interface:
(matches when <received_can_id> & mask == can_id & mask)
(matches when <received_can_id> & mask != can_id & mask)
(set error frame filter, see include/linux/can/error.h)
(join the given CAN filters - logical AND semantic)

CAN IDs, masks and data content are given and expected in hexadecimal values. When the can_id is 8 digits long the CAN_EFF_FLAG is set for 29 bit EFF format. Without any given filter all data frames are received ('0:0' default filter).

Use interface name 'any' to receive from all CAN interfaces.


candump -c -c -ta can0,123:7FF,400:700,#000000FF can2,400~7F0 can3 can8

candump -l any,0~0,#FFFFFFFF

(log only error frames but no(!) data frames)

candump -l any,0:0,#FFFFFFFF

(log error frames and also all data frames)

candump vcan2,12345678:DFFFFFFF

(match only for extended CAN ID 12345678)

candump vcan2,123:7FF

(matches CAN ID 123 - including EFF and RTR frames)

candump vcan2,123:C00007FF

(matches CAN ID 123 - only SFF and non-RTR frames)
December 2020 candump 2020.11.0-1