Fortunately `jc`[0] does parse `/proc/<pid>/stat` correctly. I, of course, originally implemented it the naive/incorrect way until a contributor fixed it. :)

    $ cat /proc/2001/stat | jc --proc
    {"pid":2001,"comm":"my program with\nsp","state":"S","ppid":1888,"pgrp":2001,"session":1888,"tty_nr":34816,"tpg_id":2001,"flags":4202496,"minflt":428,"cminflt":0,"majflt":0,"cmajflt":0,"utime":0,"stime":0,"cutime":0,"cstime":0,"priority":20,"nice":0,"num_threads":1,"itrealvalue":0,"starttime":75513,"vsize":115900416,"rss":297,"rsslim":18446744073709551615,"startcode":4194304,"endcode":5100612,"startstack":140737020052256,"kstkeep":140737020050904,"kstkeip":140096699233308,"signal":0,"blocked":65536,"sigignore":4,"sigcatch":65538,"wchan":18446744072034584486,"nswap":0,"cnswap":0,"exit_signal":17,"processor":0,"rt_priority":0,"policy":0,"delayacct_blkio_ticks":0,"guest_time":0,"cguest_time":0,"start_data":7200240,"end_data":7236240,"start_brk":35389440,"arg_start":140737020057179,"arg_end":140737020057223,"env_start":140737020057223,"env_end":140737020059606,"exit_code":0,"state_pretty":"Sleeping in an interruptible wait"}

[0] https://kellyjonbrazil.github.io/jc/docs/parsers/proc_pid_st...