getspent(), getspent_r()

Get an entry from the shadow password database


#include <sys/types.h>
#include <shadow.h>

struct spwd* getspent( void );

struct spwd* getspent_r( struct spwd* result, 
                         char* buffer, 
                         int buflen );


These arguments apply only to getspent_r():

A pointer to a spwd structure where the function can store the entry. For more information about this structure, see putspent().
A block of memory that the function can use to allocate storage referenced by the spwd structure. You can determine the maximum size needed for this buffer by calling sysconf() with an argument of _SC_GETPW_R_SIZE_MAX.
The size of the block that buffer points to, in characters.



Use the -l c option to qcc to link against this library. This library is usually included automatically.


The getspent() and getspent_r() functions return the next entry from the shadow password database. The getspent() function uses a static buffer that's overwritten by each call.

Note: The fgetspent(), getspent(), getspnam(), and functions share the same static buffer.


The getspent() function returns a pointer to an object of type struct spwd containing the next entry from the shadow password database. When getspent() is first called, the database is opened, and remains open until either a NULL is returned to signify end-of-file, or endspent() is called.


The getspent() function uses the following functions, and as a result, errno can be set to an error for any of these calls:


#include <stdio.h>
#include <stdlib.h>
#include <pwd.h>
#include <shadow.h>

 * This program loops, reading a login name from standard
 * input and checking to see if it is a valid name. If it
 * is not valid, the entire contents of the name in the
 * password database are printed.

int main(int argc, char** argv)
   struct spwd* sp;
    char  buf[80];

    setpwent( );
    while( gets( buf ) != NULL ) {
      if( ( sp = getspnam( buf ) ) != ( struct spwd * )0 ) {
        printf( "Valid login name is: %s\n", sp->sp_namp );
      } else {
        setspent( );
        while( ( sp=getspent( ) ) != ( struct spwd * )0 )
          printf( "%s\n", sp->sp_namp );
    return( EXIT_SUCCESS );



Table 1. getspent()
Cancellation point Yes
Interrupt handler No
Signal handler No
Thread No
Table 2. getspent_r()
Cancellation point Yes
Interrupt handler No
Signal handler No
Thread Yes