getline


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-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.   (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  get-
       line(),  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).

VERSIONS
       These functions are available since libc 4.6.27.

CONFORMING TO
           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 3.35 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://man7.org/linux/man-pages/.



GNU                               2010-06-12                        GETLINE(3)
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