diff options
Diffstat (limited to 'doc/emacs/files.texi')
| -rw-r--r-- | doc/emacs/files.texi | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/doc/emacs/files.texi b/doc/emacs/files.texi index 29cc22e7557..74315a05bbd 100644 --- a/doc/emacs/files.texi +++ b/doc/emacs/files.texi @@ -812,22 +812,21 @@ in these cases, customize the variable @vindex write-region-inhibit-fsync Normally, when a program writes a file, the operating system briefly caches the file's data in main memory before committing the data to -disk. This can greatly improve performance; for example, when running -on laptops, it can avoid a disk spin-up each time a file is written. -However, it risks data loss if the operating system crashes before -committing the cache to disk. +secondary storage. Although this can greatly improve performance, it +risks data loss if the system loses power before committing the cache, +and on some platforms other processes might not immediately notice the +file's change. To lessen this risk, Emacs can invoke the @code{fsync} system call after saving a file. Using @code{fsync} does not eliminate the risk -of data loss, partly because many systems do not implement +of data loss or slow notification, partly because many systems do not support @code{fsync} properly, and partly because Emacs's file-saving procedure typically relies also on directory updates that might not survive a crash even if @code{fsync} works properly. The @code{write-region-inhibit-fsync} variable controls whether Emacs invokes @code{fsync} after saving a file. The variable's -default value is @code{nil} when Emacs is interactive, and @code{t} -when Emacs runs in batch mode (@pxref{Initial Options, Batch Mode}). +default value is @code{t}. Emacs never uses @code{fsync} when writing auto-save files, as these files might lose data anyway. @@ -1738,9 +1737,13 @@ only the hunks within the region. Re-generate the current hunk (@code{diff-refresh-hunk}). @item C-c C-w +@vindex diff-ignore-whitespace-switches @findex diff-ignore-whitespace-hunk -Re-generate the current hunk, disregarding changes in whitespace -(@code{diff-ignore-whitespace-hunk}). +Re-generate the current hunk, disregarding changes in whitespace. +With a non-@code{nil} prefix arg, re-generate all the hunks +(@code{diff-ignore-whitespace-hunk}). This calls @code{diff-command} +with @code{diff-ignore-whitespace-switches}, which defaults to +@samp{-b}, meaning ignore changes in whitespace only. @item C-x 4 A @findex diff-add-change-log-entries-other-window @@ -1900,6 +1903,11 @@ following in the Trash directory: liable to also delete this @code{.dir-locals.el} file, so this should only be done if you delete files from the Trash directory manually. +@vindex remote-file-name-inhibit-delete-by-moving-to-trash + If the variable @code{remote-file-name-inhibit-delete-by-moving-to-trash} +is non-@code{nil}, remote files are never moved to the Trash. They +are deleted instead. + @ifnottex If a file is under version control (@pxref{Version Control}), you should delete it using @kbd{M-x vc-delete-file} instead of @kbd{M-x |