diff options
| -rw-r--r-- | Doc/lib/libstruct.tex | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/Doc/lib/libstruct.tex b/Doc/lib/libstruct.tex index 62892ec..eef84a4 100644 --- a/Doc/lib/libstruct.tex +++ b/Doc/lib/libstruct.tex @@ -1,15 +1,18 @@ \section{\module{struct} --- - Interpret strings as packed binary data.} + Interpret strings as packed binary data} \declaremodule{builtin}{struct} \modulesynopsis{Interpret strings as packed binary data.} -\indexii{C@\C{}}{structures} +\indexii{C}{structures} +\indexiii{packing}{binary}{data} -This module performs conversions between Python values and \C{} +This module performs conversions between Python values and C structs represented as Python strings. It uses \dfn{format strings} -(explained below) as compact descriptions of the lay-out of the \C{} -structs and the intended conversion to/from Python values. +(explained below) as compact descriptions of the lay-out of the C +structs and the intended conversion to/from Python values. This can +be used in handling binary data stored in files or from network +connections, among other sources. The module defines the following exception and functions: @@ -40,7 +43,7 @@ The module defines the following exception and functions: \end{funcdesc} Format characters have the following meaning; the conversion between -\C{} and Python values should be obvious given their types: +C and Python values should be obvious given their types: \begin{tableiii}{c|l|l}{samp}{Format}{C Type}{Python} \lineiii{x}{pad byte}{no value} @@ -96,9 +99,9 @@ example, the Alpha and Merced processors use 64-bit pointer values, meaning a Python long integer will be used to hold the pointer; other platforms use 32-bit pointers and will use a Python integer. -By default, \C{} numbers are represented in the machine's native format +By default, C numbers are represented in the machine's native format and byte order, and properly aligned by skipping pad bytes if -necessary (according to the rules used by the \C{} compiler). +necessary (according to the rules used by the C compiler). Alternatively, the first character of the format string can be used to indicate the byte order, size and alignment of the packed data, @@ -118,7 +121,7 @@ Native byte order is big-endian or little-endian, depending on the host system (e.g. Motorola and Sun are big-endian; Intel and DEC are little-endian). -Native size and alignment are determined using the \C{} compiler's +Native size and alignment are determined using the C compiler's \keyword{sizeof} expression. This is always combined with native byte order. @@ -168,6 +171,6 @@ This only works when native size and alignment are in effect; standard size and alignment does not enforce any alignment. \begin{seealso} - \seemodule{array}{packed binary storage of homogeneous data} - \seemodule{xdrlib}{packing and unpacking of XDR data} + \seemodule{array}{Packed binary storage of homogeneous data.} + \seemodule{xdrlib}{Packing and unpacking of XDR data.} \end{seealso} |