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Top Forums Programming Results Of A Variable Into An Array Using C Language Post 302929352 by Corona688 on Friday 19th of December 2014 04:54:45 PM
Old 12-19-2014
Speaking more generally, C does have a way to slurp an entire file into memory at once: mmap. It's actually better than reading it into memory, a 200MB file won't waste 200MB RAM just sitting there, only the parts you're using will actually be "read". To your program, it's a giant array of bytes corresponding to the entire file.

Since you actually want the file to be organized into lines, etc, this may not be too useful for you.
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MMAP2(2)						     Linux Programmer's Manual							  MMAP2(2)

NAME
mmap2 - map files or devices into memory SYNOPSIS
#include <sys/mman.h> void *mmap2(void *addr, size_t length, int prot, int flags, int fd, off_t pgoffset); DESCRIPTION
The mmap2() system call operates in exactly the same way as mmap(2), except that the final argument specifies the offset into the file in 4096-byte units (instead of bytes, as is done by mmap(2)). This enables applications that use a 32-bit off_t to map large files (up to 2^44 bytes). RETURN VALUE
On success, mmap2() returns a pointer to the mapped area. On error -1 is returned and errno is set appropriately. ERRORS
EFAULT Problem with getting the data from userspace. EINVAL (Various platforms where the page size is not 4096 bytes.) offset * 4096 is not a multiple of the system page size. mmap2() can return any of the same errors as mmap(2). VERSIONS
mmap2() is available since Linux 2.3.31. CONFORMING TO
This system call is Linux-specific. NOTES
Nowadays, the glibc mmap() wrapper function invokes this system call rather than the mmap(2) system call. On ia64, the unit for offset is actually the system page size, rather than 4096 bytes. SEE ALSO
getpagesize(2), mmap(2), mremap(2), msync(2), shm_open(3) COLOPHON
This page is part of release 3.25 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/. Linux 2008-04-22 MMAP2(2)
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