CANGEN(1)

✨ CANGEN(1) ✨

okay bestie, welcome to the cangen manual page — she's a User Command and she's here to serve 💅

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🎀 NAME 🎀

cangen — the manual page for cangen 2023.03-1build1, no cap

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🌸 SYNOPSIS 🌸

cangen [options] <CAN interface>

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🦋 DESCRIPTION 🦋

cangen is literally a CAN frames generator. that's the whole vibe. she makes frames and she makes them on purpose ✨

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💖 OPTIONS 💖

• -g <ms> — gap in milli seconds, and the default is 200 ms 🫶
• -a — use absolute time for the gap, periodt
• -t — use SO_TXTIME 👑
• --start <ns> — start time, measured in UTC nanoseconds ⏰
• --mark <id> — set SO_MARK to <id>, and the default is 1
• -e — generate extended frame mode (EFF) CAN frames 🦋
• -f — generate CAN FD CAN frames
• -b — generate CAN FD CAN frames with bitrate switch (BRS) 🔥
• -E — generate CAN FD CAN frames with error state (ESI) 😭
• -R — generate RTR frames
• -8 — allow DLC values greater then 8 for Classic CAN frames (yes, "then", that's how she wrote it, iykyk)
• -m — mix -e -f -b -E -R frames together, it's giving chaos and we love her
• -I <mode> — CAN ID generation mode, peep below for the deets
• -L <mode> — CAN data length code (dlc) generation mode, also below
• -D <mode> — CAN data (payload) generation mode, also also below
• -p <timeout> — poll on -ENOBUFS to write frames with <timeout> ms 💫
• -n <count> — terminate after <count> CAN frames, and the default is infinite 🌈
• -i — ignore -ENOBUFS return values on write() syscalls, living dangerously
• -x — disable local loopback of generated CAN frames 🚫
• -c <count> — number of messages to send in burst, default is 1
• -v — increment verbose level for printing sent CAN frames, stack it up for more drama 🎀

🌟 Generation modes 🌟

• 'r' => random values, and yes this is the default babe
• 'e' => random values, even ID
• 'o' => random values, odd ID
• 'i' => increment values
• <value> => fixed value (in hexadecimal for -I and -D) 💜
• => nibbles written as 'x' are randomized (only for -D) — so cute, so specific

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the gap value (in milliseconds) may have decimal places, like '-g 4.73' — she's precise like that 💅

when incrementing the CAN data the data length code minimum is set to 1.

CAN IDs and data content are given and expected in hexadecimal values. no cap, hex only 🧚

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⭐ EXAMPLES ⭐

cangen vcan0 -g 4 -I 42A -L 1 -D i -v -v

fixed CAN ID and length, with incrementing data 💖

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cangen vcan0 -e -L i -v -v -v

generate EFF frames with incrementing length, triple verbose because main character energy ✨

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cangen vcan0 -D 11223344DEADBEEF -L 8

fixed CAN data payload and fixed length 🎀

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cangen vcan0 -D 11xx3344DEADBEEF -L 8

fixed CAN data payload where the 2. byte is randomized, with a fixed length — the xx ate 💅

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cangen vcan0 -I 555 -D CCCCCCCCCCCCCCCC -L 8 -g 3.75

generate a fix busload without bit-stuffing effects 🌸

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cangen vcan0 -g 0 -i -x

full load test ignoring -ENOBUFS 🔥

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cangen vcan0 -g 0 -p 10 -x

full load test with polling and a 10ms timeout ⏰

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cangen vcan0

my favourite default :) 🫶 couldn't be me picking anything else

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ok so quick vibe check reminder: -8 really does say "greater then 8" in the original and we are NOT fixing her grammar, we are respecting her journey 😌

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and that's the whole page bestie, you're fully caught up 💜 mwah 💋

this was cangen 2023.03-1build1, dated December 2025 — from me and the rest of the User Commands girlies, slay responsibly 👑