The C and C++ Include Header Files

/usr/include/shadow.h


$ cat -n /usr/include/shadow.h

     1	/* Copyright (C) 1996-2024 Free Software Foundation, Inc.
     2	   This file is part of the GNU C Library.
     3	
     4	   The GNU C Library is free software; you can redistribute it and/or
     5	   modify it under the terms of the GNU Lesser General Public
     6	   License as published by the Free Software Foundation; either
     7	   version 2.1 of the License, or (at your option) any later version.
     8	
     9	   The GNU C Library is distributed in the hope that it will be useful,
    10	   but WITHOUT ANY WARRANTY; without even the implied warranty of
    11	   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    12	   Lesser General Public License for more details.
    13	
    14	   You should have received a copy of the GNU Lesser General Public
    15	   License along with the GNU C Library; if not, see
    16	   <https://www.gnu.org/licenses/>.  */
    17	
    18	/* Declaration of types and functions for "shadow" storage of hashed
    19	   passphrases.  The shadow database is like the user database, but is
    20	   only accessible with special privileges, so that malicious users
    21	   cannot retrieve everyone else's hashed passphrase to brute-force at
    22	   their convenience.  */
    23	
    24	#ifndef _SHADOW_H
    25	#define _SHADOW_H	1
    26	
    27	#include <features.h>
    28	
    29	#include <paths.h>
    30	
    31	#define __need_size_t
    32	#include <stddef.h>
    33	
    34	#include <bits/types/FILE.h>
    35	
    36	/* Paths to the user database files.  */
    37	#define	SHADOW _PATH_SHADOW
    38	
    39	
    40	__BEGIN_DECLS
    41	
    42	/* A record in the shadow database.  */
    43	struct spwd
    44	  {
    45	    char *sp_namp;		/* Login name.  */
    46	    char *sp_pwdp;		/* Hashed passphrase.  */
    47	    long int sp_lstchg;		/* Date of last change.  */
    48	    long int sp_min;		/* Minimum number of days between changes.  */
    49	    long int sp_max;		/* Maximum number of days between changes.  */
    50	    long int sp_warn;		/* Number of days to warn user to change
    51					   the password.  */
    52	    long int sp_inact;		/* Number of days the account may be
    53					   inactive.  */
    54	    long int sp_expire;		/* Number of days since 1970-01-01 until
    55					   account expires.  */
    56	    unsigned long int sp_flag;	/* Reserved.  */
    57	  };
    58	
    59	
    60	/* Open database for reading.
    61	
    62	   This function is not part of POSIX and therefore no official
    63	   cancellation point.  But due to similarity with an POSIX interface
    64	   or due to the implementation it is a cancellation point and
    65	   therefore not marked with __THROW.  */
    66	extern void setspent (void);
    67	
    68	/* Close database.
    69	
    70	   This function is not part of POSIX and therefore no official
    71	   cancellation point.  But due to similarity with an POSIX interface
    72	   or due to the implementation it is a cancellation point and
    73	   therefore not marked with __THROW.  */
    74	extern void endspent (void);
    75	
    76	/* Get next entry from database, perhaps after opening the file.
    77	
    78	   This function is not part of POSIX and therefore no official
    79	   cancellation point.  But due to similarity with an POSIX interface
    80	   or due to the implementation it is a cancellation point and
    81	   therefore not marked with __THROW.  */
    82	extern struct spwd *getspent (void);
    83	
    84	/* Get shadow entry matching NAME.
    85	
    86	   This function is not part of POSIX and therefore no official
    87	   cancellation point.  But due to similarity with an POSIX interface
    88	   or due to the implementation it is a cancellation point and
    89	   therefore not marked with __THROW.  */
    90	extern struct spwd *getspnam (const char *__name);
    91	
    92	/* Read shadow entry from STRING.
    93	
    94	   This function is not part of POSIX and therefore no official
    95	   cancellation point.  But due to similarity with an POSIX interface
    96	   or due to the implementation it is a cancellation point and
    97	   therefore not marked with __THROW.  */
    98	extern struct spwd *sgetspent (const char *__string);
    99	
   100	/* Read next shadow entry from STREAM.
   101	
   102	   This function is not part of POSIX and therefore no official
   103	   cancellation point.  But due to similarity with an POSIX interface
   104	   or due to the implementation it is a cancellation point and
   105	   therefore not marked with __THROW.  */
   106	extern struct spwd *fgetspent (FILE *__stream);
   107	
   108	/* Write line containing shadow entry to stream.
   109	
   110	   This function is not part of POSIX and therefore no official
   111	   cancellation point.  But due to similarity with an POSIX interface
   112	   or due to the implementation it is a cancellation point and
   113	   therefore not marked with __THROW.  */
   114	extern int putspent (const struct spwd *__p, FILE *__stream);
   115	
   116	
   117	#ifdef __USE_MISC
   118	/* Reentrant versions of some of the functions above.
   119	
   120	   These functions are not part of POSIX and therefore no official
   121	   cancellation point.  But due to similarity with an POSIX interface
   122	   or due to the implementation they are cancellation points and
   123	   therefore not marked with __THROW.  */
   124	extern int getspent_r (struct spwd *__result_buf, char *__buffer,
   125			       size_t __buflen, struct spwd **__result)
   126		__attr_access ((__write_only__, 2, 3));
   127	
   128	extern int getspnam_r (const char *__name, struct spwd *__result_buf,
   129			       char *__buffer, size_t __buflen,
   130			       struct spwd **__result)
   131		__attr_access ((__write_only__, 3, 4));
   132	
   133	extern int sgetspent_r (const char *__string, struct spwd *__result_buf,
   134				char *__buffer, size_t __buflen,
   135				struct spwd **__result)
   136		__attr_access ((__write_only__, 3, 4));
   137	
   138	extern int fgetspent_r (FILE *__stream, struct spwd *__result_buf,
   139				char *__buffer, size_t __buflen,
   140				struct spwd **__result)
   141		__attr_access ((__write_only__, 3, 4));
   142	#endif	/* misc */
   143	
   144	
   145	/* The simple locking functionality provided here is not suitable for
   146	   multi-threaded applications.  */
   147	
   148	/* Request exclusive access to /etc/passwd and /etc/shadow.  */
   149	extern int lckpwdf (void) __THROW;
   150	
   151	/* Release exclusive access to /etc/passwd and /etc/shadow.  */
   152	extern int ulckpwdf (void) __THROW;
   153	
   154	__END_DECLS
   155	
   156	#endif /* shadow.h */