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



NAME
       getline, getdelim - delimited string input

SYNOPSIS
       #define _GNU_SOURCE
       #include <&lt;stdio.h>&gt;

       ssize_t getline(char **lineptr, size_t *n, FILE *stream);

       ssize_t getdelim(char **lineptr, size_t *n, int delim, FILE *stream);

DESCRIPTION
       getline()  reads an entire line from stream, storing the address of the
       buffer containing the text into *lineptr.  The  buffer  is  null-termi-
       nated and includes the newline character, if one was found.

       If  *lineptr is NULL, then getline() will allocate a buffer for storing
       the line, which should be freed by the user program.  (The value in  *n
       is ignored.)

       Alternatively, before calling getline(), *lineptr can contain a pointer
       to a malloc(3)-allocated buffer *n bytes in size.  If the buffer is not
       large  enough  to  hold the line, getline() resizes it with realloc(3),
       updating *lineptr and *n as necessary.

       In either case, on a successful call, *lineptr and *n will  be  updated
       to reflect the buffer address and allocated size respectively.

       getdelim()  works  like  getline(),  except a line delimiter other than
       newline can be specified as the delimiter argument.  As with getline(),
       a  delimiter character is not added if one was not present in the input
       before end of file was reached.

RETURN VALUE
       On success, getline() and getdelim() return the  number  of  characters
       read,  including  the delimiter character, but not including the termi-
       nating null byte.  This value can be used to handle embedded null bytes
       in the line read.

       Both  functions  return -1  on failure to read a line (including end of
       file condition).

ERRORS
       EINVAL Bad arguments (n or lineptr is NULL, or stream is not valid).

CONFORMING TO
       Both getline() and getdelim() are GNU extensions.  They  are  available
       since libc 4.6.27.

EXAMPLE
       #define _GNU_SOURCE
       #include <stdio.h>
       #include <stdlib.h>

       int
       main(void)
       {
           FILE * fp;
           char * line = NULL;
           size_t len = 0;
           ssize_t read;

           fp = fopen("/etc/motd", "r");
           if (fp == NULL)
               exit(EXIT_FAILURE);

           while ((read = getline(&line, &len, fp)) != -1) {
               printf("Retrieved line of length %zu :\n", read);
               printf("%s", line);
           }

           if (line)
               free(line);
           exit(EXIT_SUCCESS);
       }

SEE ALSO
       read(2),   fgets(3),   fopen(3),   fread(3),  gets(3),  scanf(3),  fea-
       ture_test_macros(7)

COLOPHON
       This page is part of release 3.05 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                               2006-05-17                        GETLINE(3)