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 24  .\" $Id$
 25  .\"
 26  .Dd June 28, 2006
 27  .Os
 28  .Dt ELF_MEMORY 3
 29  .Sh NAME
 30  .Nm elf_memory
 31  .Nd process an ELF or ar(1) archive mapped into memory
 32  .Sh LIBRARY
 33  .Lb libelf
 34  .Sh SYNOPSIS
 35  .In libelf.h
 36  .Ft "Elf *"
 37  .Fn elf_memory "char *image" "size_t size"
 38  .Sh DESCRIPTION
 39  Function
 40  .Fn elf_memory
 41  is used to process an ELF file or
 42  .Xr ar 1
 43  archive whose image is present in memory.
 44  .Pp
 45  Argument
 46  .Ar image
 47  points to the start of the memory image of the file or archive.
 48  Argument
 49  .Ar size
 50  contains the size in bytes of the memory image.
 51  .Pp
 52  The ELF descriptor is created for reading (i.e., analogous to the
 53  use of
 54  .Xr elf_begin 3
 55  with a command argument value of
 56  .Dv ELF_C_READ Ns ).
 57  .Sh RETURN VALUES
 58  Function
 59  .Fn elf_memory
 60  returns a pointer to a new ELF descriptor if successful, or NULL if an
 61  error occurred.
 62  .Pp
 63  The return value may be queried for the file type using
 64  .Xr elf_kind 3 .
 65  .Sh EXAMPLES
 66  To read parse an elf file, use:
 67  .Bd -literal -offset indent
 68  int fd;
 69  void *p;
 70  struct stat sb;
 71  Elf *e;
 72  \&...
 73  if ((fd = open("./elf-file", O_RDONLY)) < 0 ||
 74      fstat(fd, &sb) < 0 ||
 75      (p = mmap(NULL, sb.st_size, PROT_READ, MAP_PRIVATE, fd, (off_t) 0)) ==
 76      MAP_FAILED) {
 77  	... handle system error ...
 78  }
 79  
 80  if ((e = elf_memory(p, sb.st_size)) == NULL) {
 81  	... handle elf(3) error ...
 82  }
 83  \&... use ELF descriptor "e" here ...
 84  .Ed
 85  .Sh ERRORS
 86  Function
 87  .Fn elf_memory
 88  can fail with the following errors:
 89  .Bl -tag -width "[ELF_E_RESOURCE]"
 90  .It Bq Er ELF_E_ARGUMENT
 91  A NULL value was used for argument
 92  .Ar image
 93  or the value of argument
 94  .Ar sz
 95  was zero.
 96  .It Bq Er ELF_E_HEADER
 97  The header of the ELF object contained an unsupported value in its
 98  .Va e_ident[EI_CLASS]
 99  field.
100  .It Bq Er ELF_E_HEADER
101  The header of the ELF object contained an unsupported value in its
102  .Va e_ident[EI_DATA]
103  field.
104  .It Bq Er ELF_E_RESOURCE
105  An out of memory condition was detected.
106  .It Bq Er ELF_E_SEQUENCE
107  Function
108  .Fn elf_memory
109  was called before a working version was set using
110  .Xr elf_version 3 .
111  .It Bq Er ELF_E_VERSION
112  The ELF object referenced by argument
113  .Ar image
114  was of an unsupported ELF version.
115  .El
116  .Sh SEE ALSO
117  .Xr elf 3 ,
118  .Xr elf_begin 3 ,
119  .Xr elf_end 3 ,
120  .Xr elf_errno 3 ,
121  .Xr elf_kind 3 ,
122  .Xr gelf 3