NAME

       getline, getdelim - delimited string input

SYNOPSIS

       #include <stdio.h>

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

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

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

       getline(), getdelim():
           Since glibc 2.10:
               _POSIX_C_SOURCE >= 200809L || _XOPEN_SOURCE >= 700
           Before glibc 2.10:
               _GNU_SOURCE

DESCRIPTION

       getline()  reads  an entire line from stream, storing the address of the buffer containing
       the text into *lineptr.  The buffer is null-terminated 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.  (In this case, 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 that 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 terminating null byte ('\0').  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).  In
       the event of an error, errno is set to indicate the cause.

ERRORS

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

VERSIONS

       These functions are available since libc 4.6.27.

CONFORMING TO

       Both getline() and getdelim() were originally GNU extensions.  They were  standardized  in
       POSIX.1-2008.

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);
           }

           free(line);
           exit(EXIT_SUCCESS);
       }

SEE ALSO

       read(2), fgets(3), fopen(3), fread(3), gets(3), scanf(3)

COLOPHON

       This  page  is  part of release 3.54 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/.