cpio

Purpose

     Describes copy in and out (cpio) archive file.

Description

     When the  -c flag of  the cpio  command is not  used, the
     header structure is:

          struct {
            short
               h_magic,
               h_dev;
            unsigned short
               h_ino,
               h_mode,
               h_uid,
               h_gid;
            short
               h_nlink,
               h_rdev,
               h_mtime[2],
               h_namesize,
               h_filesize[2];
            char
               h_name[n];         /* described below */
          } Hdr;

     When  the cpio  command is  used  with the  -c flag,  the
     header for the cpio structure may be read as:

         sscanf(Chdr,"%6ho%6ho%6ho%6ho%6ho%6ho%6ho%6ho%11lo%6ho%11lo%s",
         &Hdr.h_magic, &Hdr.h_dev, &Hdr.h_ino, &Hdr.h_mode,
         &Hdr.h_uid, &Hdr.h_gid, &Hdr.h_nlink, &Hdr.h_rdev,
         &Longtime, &Hdr.h_namesize, &Longfile, &Hdr.h_name);

     Longtime and  Longfile are equivalent to  Hdr.h_mtime and
     Hdr.h_filesize, respectively.  The  contents of each file
     together  with  other  items   describing  the  file  are
     recorded in  an element  of the  array of  varying length
     structures.   The member  h_magic  contains the  constant
     octal 070707 (or 0x71c7).   The stat system call explains
     the meaning  of structure members h_dev  through h_mtime.
     The  length of  the  null-terminated  path name,  h_name,
     including  the null  byte is  indicated by  n, where  n =
     (h_namesize  % 2)  + h_namesize.   In other  words, n  is
     equal to h_namesize if h_namesize is even.  If h_namesize
     is odd, n is equal to h_namesize + 1.

     The last record  of the archive always  contains the name
     "TRAILER!!!" Special files,  directories, and the trailer
     are recorded with h_filesize equal to 0.

Related Information

     In this book:  "scanf, fscanf, sscanf, NLscanf, NLfscanf,
     NLsscanf" and "stat, fstat."

     The cpio and  find commands in AIX  Operating System Com-
     mands Reference.