Read environment variables of a process in Linux

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When try to get the content of any /proc/PID/environ file in more readable format, you can:

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/proc/[pid]/environ
      This file contains the environment for the process.  The entries
      are separated by null bytes ('\0'), and there may be a null byte
      at the end.

A simple way is to apply xargs -0 -L1 -a on it:

  • -0 - read null-delimited lines,
  • -L1 - read one line per execution of command
  • -a - file read lines from file
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# ps -aef
10101     3629  3589  0 Apr27 ?        00:00:00 /bin/bash bin/start
10101     3670  3629  0 Apr27 ?        00:00:00 /bin/bash bin/start-tomcat
10101     3671  3670  0 Apr27 ?        00:07:36 /usr/lib/jvm/java-11-amazon-corretto.x86_64/bin/java -Djava.util.logging.config.file=/usr/local/tomcat/conf/

# cat /proc/3629/environ
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/binHOSTNAME=27c44e8a5c7cJAVA_HOME=/usr/lib/jvm/java-11-amazon-corretto.x86_64HOME=/usr/local/tomcat

# xargs -0 -L1 -a /proc/3629/environ
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=27c44e8a5c7c
JAVA_HOME=/usr/lib/jvm/java-11-amazon-corretto.x86_64
HOME=/usr/local/tomcat

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