gfs_pio_gets(3) [debian man page]

GFS_PIO_GETS(3) 														   GFS_PIO_GETS(3)

NAME

       gfs_pio_gets - read one line

SYNOPSIS

       #include <gfarm/gfarm.h>

       char *gfs_pio_gets (GFS_File f, char * s, size_t size);

DESCRIPTION

       gfs_pio_gets()  reads one line from the file specified by the parameter gf to the buffer specified by the parameter s.  You need to specify
       the size of the buffer by the parameter size.

       Unlike gfs_pio_getline(3), this function doesn't remove newline character at the end of the buffer. But if whole contents of the line  can-
       not  be	stored to the buffer due to its length, or if the file reaches the end without newline, there will be no newline at the end of the
       buffer. In any case, one '' character is appended to the end of the buffer.

       If the file reaches its end, the length of the string in the buffer becomes 0.

RETURN VALUES

       NULL   The function terminated successfully.

       GFARM_ERR_NO_MEMORY
	      Insufficient memory was available.

       Others An error except the above occurred.  The reason is shown by its pointed strings.

EXAMPLES

   EXAMPLE OF GFS_PIO_GETS FUNCTION
       #include <stdio.h>
       #include <stdlib.h>
       #include <gfarm/gfarm.h>

       int
       main(int argc, char **argv)
       {
	    char *e;
	    GFS_File gf;
	    char buffer[512];

	    e = gfarm_initialize(&argc, &argv);
	    if (e != NULL) {
		 fprintf(stderr, "gfarm_initialize: %s
", e);
		 return (EXIT_FAILURE);
	    }
	    if (argc <= 1) {
		 fprintf(stderr, "missing gfarm filename
");
		 return (EXIT_FAILURE);
	    }
	    e = gfs_pio_open(argv[1], GFARM_FILE_RDONLY, &gf);
	    if (e != NULL) {
		 fprintf(stderr, "%s: %s
", argv[1], e);
		 return (EXIT_FAILURE);
	    }
	    e = gfs_pio_set_view_global(gf, 0);
	    if (e != NULL) {
		 fprintf(stderr, "%s: gfs_pio_set_view_global: %s
",
		     argv[1], e);
		 return (EXIT_FAILURE);
	    }

	    while ((e = gfs_pio_gets(gf, buffer, sizeof buffer)) != NULL &&
		*buffer != '') {
		 printf("got: %s", buffer);
	    }
	    if (e != NULL) {
		 fprintf(stderr, "ERROR: %s
", e);
		 return (EXIT_FAILURE);
	    }
	    e = gfs_pio_close(gf);
	    if (e != NULL) {
		 fprintf(stderr, "gfs_pio_close: %s
", e);
		 return (EXIT_FAILURE);
	    }
	    e = gfarm_terminate();
	    if (e != NULL) {
		 fprintf(stderr, "gfarm_initialize: %s
", e);
		 return (EXIT_FAILURE);
	    }
	    return (EXIT_SUCCESS);
       }

SEE ALSO

       gfs_pio_open(3), gfs_pio_getline(3), gfs_pio_readline(3), gfs_pio_readdelim(3)

Gfarm								    13 May 2004 						   GFS_PIO_GETS(3)

GETGROUPLIST(3) 					     Linux Programmer's Manual						   GETGROUPLIST(3)

NAME

       getgrouplist - get list of groups to which a user belongs

SYNOPSIS

       #include <grp.h>

       int getgrouplist(const char *user, gid_t group,
			gid_t *groups, int *ngroups);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       getgrouplist(): _BSD_SOURCE

DESCRIPTION

       The  getgrouplist()  function scans the group database (see group(5)) to obtain the list of groups that user belongs to.  Up to *ngroups of
       these groups are returned in the array groups.

       If it was not among the groups defined for user in the group database, then group is included in the list of groups  returned  by  getgrou-
       plist(); typically this argument is specified as the group ID from the password record for user.

       The  ngroups  argument  is a value-result argument: on return it always contains the number of groups found for user, including group; this
       value may be greater than the number of groups stored in groups.

RETURN VALUE

       If the number of groups of which user is a member is less than or equal to *ngroups, then the value *ngroups is returned.

       If the user is a member of more than *ngroups groups, then getgrouplist() returns -1.  In this case the value returned in *ngroups  can	be
       used to resize the buffer passed to a further call getgrouplist().

VERSIONS

       This function is present since glibc 2.2.4.

CONFORMING TO

       This function is nonstandard; it appears on most BSDs.

BUGS

       In  glibc  versions before 2.3.3, the implementation of this function contains a buffer-overrun bug: it returns the complete list of groups
       for user in the array groups, even when the number of groups exceeds *ngroups.

EXAMPLE

       The program below displays the group list for the user named in its first command-line argument.  The second command-line  argument  speci-
       fies the ngroups value to be supplied to getgrouplist().  The following shell session shows examples of the use of this program:

	   $ ./a.out cecilia 0
	   getgrouplist() returned -1; ngroups = 3
	   $ ./a.out cecilia 3
	   ngroups = 3
	   16 (dialout)
	   33 (video)
	   100 (users)

   Program source

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

       int
       main(int argc, char *argv[])
       {
	   int j, ngroups;
	   gid_t *groups;
	   struct passwd *pw;
	   struct group *gr;

	   if (argc != 3) {
	       fprintf(stderr, "Usage: %s <user> <ngroups>
", argv[0]);
	       exit(EXIT_FAILURE);
	   }

	   ngroups = atoi(argv[2]);

	   groups = malloc(ngroups * sizeof (gid_t));
	   if (groups == NULL) {
	       perror("malloc");
	       exit(EXIT_FAILURE);
	   }

	   /* Fetch passwd structure (contains first group ID for user) */

	   pw = getpwnam(argv[1]);
	   if (pw == NULL) {
	       perror("getpwnam");
	       exit(EXIT_SUCCESS);
	   }

	   /* Retrieve group list */

	   if (getgrouplist(argv[1], pw->pw_gid, groups, &ngroups) == -1) {
	       fprintf(stderr, "getgrouplist() returned -1; ngroups = %d
",
		       ngroups);
	    exit(EXIT_FAILURE);
	   }

	   /* Display list of retrieved groups, along with group names */

	   fprintf(stderr, "ngroups = %d
", ngroups);
	   for (j = 0; j < ngroups; j++) {
	       printf("%d", groups[j]);
	       gr = getgrgid(groups[j]);
	       if (gr != NULL)
		   printf(" (%s)", gr->gr_name);
	       printf("
");
	   }

	   exit(EXIT_SUCCESS);
       }

SEE ALSO

       getgroups(2), setgroups(2), getgrent(3), group(5), passwd(5)

COLOPHON

       This  page is part of release 3.44 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

GNU
								    2008-07-03							   GETGROUPLIST(3)