Bash环境变量HISTSIZE与HISTFILESIZE的区别

[woodongwong]

Stack Overflow上有一个很有意思的答案： https://stackoverflow.com/a/19454838

一开始答主以一个非常完整的、详细的答案来回答的，结果有人评论说太长了，可以总结一下，后来答主把答案分成了简版和详版。这里引用一下简版答案：

HISTSIZE is the number of lines or commands that are stored in memory in a history list while your bash session is ongoing.

HISTFILESIZE is the number of lines or commands that (a) are allowed in the history file at startup time of a session, and (b) are stored in the history file at the end of your bash session for use in future sessions.

Notice the distinction between file: on disk - and list: in memory.

大概意思：

• HISTSIZE是存储在内存中的历史命令的条数（当前正在进行的会话）。
• HISTFILESIZE
  • 会话启动时，历史文件（.bash_history）中允许的命令行数
  • 会话结束时，存储在历史文件（.bash_history）中以供将来新会话使用的命令行数