Linux Certif

Toute la documentation sur la certification Linux LPI

gfs_pio_readdelim

NAME

gfs_pio_readdelim - read one record

SYNOPSIS

#include <gfarm/gfarm.h>

char *gfs_pio_readdelim (GFS_File f, char **bufp, size_t *sizep, size_t *lenp, char *delimiter, size_t delimlen);

DESCRIPTION

gfs_pio_readdelim() works like gfs_pio_readline(), except a delimiter of input records is not always newline, and can be specified. This function reads one record from the file specified by the parameter gf, by using the parameter delimiter as the delimiter of the input records. You can include '\0' character in the delimiter, So, you have to specify the length of the delimiter by the parameter delimlen. If parameter delimiter is NULL, this function reads entire file as one record. Otherwise, and if the parameter delimlen is 0, this function treats two or more consecutive empty lines (/\n\n+/ in a regular expression) as the input delimiter. This feature is derived from INPUT_RECORD_SEPARATOR in perl language.

Parameter bufp specifies an address of a pointer variable initialzed by NULL at first. gfs_pio_readdelim() allocates a buffer for I/O dynamically, and stores the address of the buffer to this variable pointed by bufp. Parameter sizep specifies an address of a size_t variable initialized by 0. This size_t variable is used to record the size of the buffer. Or, you can specify a buffer allocated by malloc(3) in the variable pointed by the parameter bufp. In this case, you have to specify the size of the allocated buffer by the parameter sizep. If the length of the record exceeds the size of the buffer, the buffer will be automatically realloc(3)ed, and the variable pointed by bufp and sizep will be updated respectively. Note that you are responsible to free(3) this buffer.

This function returns the length of the record to a variable pointed by the parameter lenp. This length includes the length of the record delimiter.

This function doesn't remove the delimiter at the end of records. Also, despite that you can use the value returned by the variable pointed by lenp, this function always appends \0' character at the end of records.

If the file reaches its end, the length of the result record becomes 0.

gfs_pio_readdelim(f, bufp, sizep, lenp, "\n", 1) is equivalent to gfs_pio_readline() function.

RETURN VALUES

NULL

The function terminated successfully.

GFARM_ERR_NO_MEMORY

Insufficient memory was available.

Note that you need to free(3) the buffer pointed by the parameter bufp

Others

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

EXAMPLES

EXAMPLE OF GFS_PIO_READDELIM FUNCTION

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <gfarm/gfarm.h>
 
 int
 main(int argc, char **argv)
 {
         char *e;
         GFS_File gf;
         size_t bufsize = 0, delimlen = 1, len;
         char *buffer = NULL, *delim = "\n";
 
         e = gfarm_initialize(&argc, &argv);
         if (e != NULL) {
                 fprintf(stderr, "gfarm_initialize: %s\n", e);
                 return (EXIT_FAILURE);
         }
         while ((c = getopt(argc, argv, "d:D")) != -1) {
                 switch (c) {
                 case 'd':
                         delim = optarg;
                         delimlen = strlen(optarg);
                         break;
                 case 'D':
                         delim = NULL;
                         delimlen = 0;
                         break;
                 case '?':
                 default:
                         fprintf(stderr, "invalid option: %c\n", c);
                         return (EXIT_FAILURE);
                 }
         }
         if (optind >= argc) {
                 fprintf(stderr, "missing gfarm filename\n");
                 return (EXIT_FAILURE);
         }
         e = gfs_pio_open(argv[optind], GFARM_FILE_RDONLY, &gf);
         if (e != NULL) {
                 fprintf(stderr, "%s: %s\n", argv[optind], e);
                 return (EXIT_FAILURE);
         }
         e = gfs_pio_set_view_global(gf, 0);
         if (e != NULL) {
                 fprintf(stderr, "%s: gfs_pio_set_view_global: %s\n",
                     argv[optind], e);
                 return (EXIT_FAILURE);
         }
 
         while ((e = gfs_pio_readdelim(gf, &buffer, &bufsize, &len,
             delim, delimlen)) == NULL && len > 0) {
                 printf("<%6d/%6d >%s", len, bufsize, buffer);
         }
         if (buffer != NULL)
                 free(buffer);
         if (e != NULL) {
                 fprintf(stderr, "ERROR: %s\n", e);
                 return (EXIT_FAILURE);
         }
         e = gfs_pio_close(gf);
         if (e != NULL) {
                 fprintf(stderr, "gfs_pio_close: %s\n", e);
                 return (EXIT_FAILURE);
         }
         e = gfarm_terminate();
         if (e != NULL) {
                 fprintf(stderr, "gfarm_initialize: %s\n", e);
                 return (EXIT_FAILURE);
         }
         return (EXIT_SUCCESS);
 }
 

SEE ALSO

gfs_pio_open(3), gfs_pio_getline(3), gfs_pio_gets(3), gfs_pio_readline(3)