rlwrap cannot read/write its own history after sudo rlwrap in Ubuntu

[hanslub42]

See this question on Stack Overflow

Ubuntu's sudo preserves the value of $HOME. After a sudo rlwrap xxx xxxs history file will be owned by root, so that a subsequent invocation of rlwrap as the original user will fail with rlwrap: cannot read and write /home/user/.xxx_history: Permission denied

My first reaction would be that this is a screw-up by Ubuntu. But how do other programs avoid the problem (if at all)?

Note: the preserving of $HOME is the default under Ubuntu (they apply a special patch to sudo) but can be specified in /etc/sudoers on any system. Hence, it is not 100% fair to call this an Ubuntu problem. But I do feel that any user that messes with env_keep in /etc/sudoers can be expected to know what she is doing, while unsuspecting Ubuntu users likely will be flummoxed by this error.

In the meantime, the problem can be avoided by adding the user name to the history file name:

    rlwrap --history-filename=$HOME/.${USER}_command_history command

[hanslub42]

... or should rlwrap always use ~$USER instead of $HOME to construct the history filename?

[hanslub42]

Idea: if the history is not owned by the (real) user , treat it as read-only:

struct stat buf;

stat("bla_history", &buf);
if (buf.st_uid != getuid())
   write_histfile = FALSE;

[hanslub42]

Closed initially (incorrectly) by 4ad17ef, then by 2d7b940

[hanslub42]

Apparenly, Ubuntu has mended its ways. Closing.