Re: strtok, bus error

thank you for that precise explanation.
objdump is now less cryptic to me...
- ben

Glynn Clements a écrit :
> ben wrote:
>> i don't know if it is a compiler feature (storage behavior into the DATA
>> segment), or a linux kernel feature, or if it is specified in ANSI, but
>> the second way leads to pointing to a _constant_ string. If someone can
>> enlighten...
> 
> ANSI C says that string literals "may" be read-only. On platforms with
> memory protection they usually are read-only.
> 
> On Linux, string literals are stored in the "rodata" segment, which is
> read-only, and thus can be shared between all processes which are
> using a given executable or shared library.
> 
> You can list the segments which make up an executable or shared
> library using "objdump -h"
> [snipped]
> 
> The main ones are text, rodata, data, and bss.
> 
> The text segment holds code, and is read-only and executable (CODE
> flag).
> 
> The others hold static data: global variables, "static" local
> variables, string literals, and intialisers for automatic
> (non-"static" local) arrays.
> 
> Read-only data (literals, initialisers, "const" variables) goes into
> the rodata segment, which is read-only.
> 
> Mutable variables with explicit initialisers go into the data segment.
> 
> Mutable variables without initialisers (i.e. implicitly initialised to
> zero) go into the bss segment. As the entire bss segment is initially
> zero, it doesn't need to be stored in the file (this is indicated by
> the lack of the CONTENTS, LOAD, and CODE/DATA flags).
> 
> The other segments tend to be architecture-specific.


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