CPIO

Section: File Formats (5)
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BSD mandoc
 

NAME

cpio - format of cpio archive  

DESCRIPTION

The header structure, when the -c option of cpio(1) is not used, is:
struct {
        short   h_magic,
                h_dev;
        ushort  h_ino,
                h_mode,
                h_uid,
                h_gid;
        short   h_nlink,
                h_rdev,
                h_mtime[2],
                h_namesize,
                h_filesize[2];
        char    h_name[h_namesize rounded to word];
} Hdr;

When the -c option is used, the header information is described by:

sscanf(Chdr,"%6o%6o%6o%6o%6o%6o%6o%6o%11lo%6o%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);

Fa Longtime and Fa Longfile are equivalent to Fa Hdr.h_mtime and Fa Hdr.h_filesize , respectively. The contents of each file are recorded in an element of the array of varying lenght structures, archive, together with other items describing the file. Every instance of Fa h_magic contains the constant 070707 (octal). The itimes Fa h_dev through Fa h_mtime have meanings explained in stat(2). The length of the null-terminated path name Fa H_name , icluding the null byte, is given by Fa h_namesize .

The last record of the archive always contains the name TRAILER!!!. Special files, directories, and the trailer are recorded with Fa H_filesize equal to zero.  

SEE ALSO

cpio(1), find(1), stat(2)  

HISTORY

A cpio(1) command appeared in AT&T System V . This file format is derived from the AT&T System V sources which were contributed to the public domain by AT&T.


 

Index

NAME
DESCRIPTION
SEE ALSO
HISTORY

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Time: 06:31:23 GMT, May 19, 2025