From: Stefan Kangas Date: Wed, 23 Oct 2019 23:08:30 +0000 (+0200) Subject: Update FAQ section on large files (Bug#37818) X-Git-Tag: emacs-27.0.90~897 X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=b3b74514e98e2fc85c261a1444ce2db0cf23abfc;p=emacs.git Update FAQ section on large files (Bug#37818) * doc/misc/efaq.texi (Problems with very large files): Extend section and remove information about ancient versions of Emacs. --- diff --git a/doc/misc/efaq.texi b/doc/misc/efaq.texi index 0b7b6d9c9f2..29461bec7a6 100644 --- a/doc/misc/efaq.texi +++ b/doc/misc/efaq.texi @@ -2918,20 +2918,29 @@ type @kbd{C-h C-p} to read it. @end menu @node Problems with very large files -@section Does Emacs have problems with files larger than 8 megabytes? +@section Does Emacs have problems with large files? @cindex Very large files, opening @cindex Large files, opening @cindex Opening very large files @cindex Maximum file size @cindex Files, maximum size -Old versions (i.e., anything before 19.29) of Emacs had problems editing -files larger than 8 megabytes. In versions 19.29 and later, the maximum -buffer size is at least @math{2^{27}-1}, or 134,217,727 bytes, or 132 MBytes. -The maximum buffer size on 32-bit machines increased to 256 MBytes in -Emacs 22, and again to 512 MBytes in Emacs 23.2. +Emacs has an inherent fixed limitation on the size of buffers. This +limit is stricter than the maximum size of objects supported by other +programs on the same architecture. -Emacs compiled on a 64-bit machine can handle much larger buffers. +The maximum buffer size on 32-bit machines is 512 MBytes beginning +with version 23.2. If Emacs was built using the +@code{--with-wide-int} flag, the maximum buffer size on 32-bit +machines is 2 GB. + +Emacs compiled on a 64-bit machine can handle much larger buffers; up +to @code{most-positive-fixnum} (2.3 exabytes). + +Due to things like decoding of multibyte characters, you can only +visit files with a size that is roughly half the buffer size limit. +When visiting compressed archives, the file size limit will be +smaller than that due to decompression. @node ^M in the shell buffer @section How do I get rid of @samp{^M} or echoed commands in my shell buffer?