getline(3) 맨 페이지 - 윈디하나의 솔라나라

개요

섹션
맨 페이지 이름
검색(S)

getline(3)

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

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
           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 set to NULL and *n is set 0 before the call, then get‐
       line() will allocate a buffer for storing the line.  This buffer should
       be freed by the user program even if getline() failed.

       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  ('\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).

       ENOMEM Allocation or reallocation of the line buffer failed.

ATTRIBUTES
       For an explanation of the terms  used  in  this  section,  see  attrib‐
       utes(7).  allbox; lbw21 lb lb l l l.  Interface Attribute Value T{ get‐
       line(), getdelim() T}   Thread safety  MT-Safe


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(int argc, char *argv[])
       {
           FILE *stream;
           char *line = NULL;
           size_t len = 0;
           ssize_t nread;

           if (argc != 2) {
               fprintf(stderr, "Usage: %s <file>\n", argv[0]);
               exit(EXIT_FAILURE);
           }

           stream = fopen(argv[1], "r");
           if (stream == NULL) {
               perror("fopen");
               exit(EXIT_FAILURE);
           }

           while ((nread = getline(&line, &len, stream)) != -1) {
               printf("Retrieved line of length %zu:\n", nread);
               fwrite(line, nread, 1, stdout);
           }

           free(line);
           fclose(stream);
           exit(EXIT_SUCCESS);
       }

SEE ALSO
       read(2), fgets(3), fopen(3), fread(3), scanf(3)

COLOPHON
       This page is part of release 5.02 of the Linux  man-pages  project.   A
       description  of  the project, information about reporting bugs, and the
       latest    version    of    this    page,    can     be     found     at
       https://www.kernel.org/doc/man-pages/.

GNU                               2019-03-06                        GETLINE(3)
맨 페이지 내용의 저작권은 맨 페이지 작성자에게 있습니다.
RSS ATOM XHTML 5 CSS3