06-17-2012
Hi, Scrutinizer.
Quote:
Originally Posted by
Scrutinizer
It seems to me any solution should always make use a temporary intermediate file for safety reasons. If we read the whole file into memory and then write it back to the same file, we run the risk of losing the original in case of power failure during the write-back phase..
With a temporary file there is only mv involved, which is only a rename if the temporary file is in the same dir on the same file system, so a temporary file in the same directory instead of /tmp for example may be preferably. If we use /tmp for example for the intermediate file, a temporary rename to .bak of the original until the move from /tmp may be required and safest will probably be to keep the .bak until the user deletes it..
When was the last time you know that that happened to
anyone? Most important *nix boxes will be backed up with a UPS. I think it is
far more likely to fall prey to plain old
user error.
However, I sometimes allow myself the luxury of following:
Quote:
"Unix was not designed to stop its users from doing stupid things, as that would also stop them from doing clever things." - Doug Gwyn
--
Unix philosophy - Wikipedia, the free encyclopedia
Best wishes ... cheers, drl
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LEARN ABOUT DEBIAN
dh-exec-install
DH-EXEC-INSTALL(1) dh-exec DH-EXEC-INSTALL(1)
NAME
dh-exec-install - Install (and possibly rename) files.
SYNOPSIS
#! /usr/bin/dh-exec
debian/default.conf => /etc/my-package/start.conf
usr/bin/*
DESCRIPTION
Being a sub-command of dh-exec(1), this program must not be ran directly, but through dh-exec, which automatically runs all available
sub-commands if run bare; or explicitly with dh-exec --with=install.
It is meant to be used for dh_install(1) files, and those alone. If it finds that its input is not such a file, it will do nothing, but
echo back the contents.
The purpose of the program is to extend dh_install(1)'s functionality, by allowing to specify a destination filename.
This can be accomplished by a special syntax: the " => " mark between a source and a destination means that the source file should be
installed with the specified destination name.
For obvious reasons, the source must not be a wildcard, and the destination in this case must be a file, and not a directory.
All other non-comment lines are left alone.
RESTRICTIONS
Due to the way executable scripts are called from debhelper(1), there is no way to know what options were used for the original
dh_install(1). This means, that the --sourcedir option of dh_install(1) will not work correctly when dh-exec-install is in use.
IMPLEMENTATION
Internally, the renaming happens by creating a temporary directory under debian/tmp/, and copying (or moving, if the source was under
debian/tmp/ to begin with) the file there, with the new name.
This is done this way to allow dh_install(1) to do the real copying, and allow its options to continue working, even when renaming is
involved.
The temporary directory is put under debian/tmp so that it will be cleaned by dh_prep(1) when the clean target gets to run. Thus, no extra
code is needed anywhere to clean up the renamed files.
ENVIRONMENT
DH_EXEC_SCRIPTDIR
Indicates which directory the command-specific scripts should be sought for. If not specified, scripts will be searched for in
/usr/share/dh-exec/.
FILES
$DH_EXEC_SCRIPTDIR/dh-exec-install-*
The various scripts for the higher-level program.
SEE ALSO
debhelper(1), dh-exec(1), dh_install(1)
AUTHOR
dh-exec-install is copyright (C) 2011-2012 by Gergely Nagy <algernon@madhouse-project.org>.
2012-05-03 DH-EXEC-INSTALL(1)