> Linux Man Page: "free"


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The Linux Documentation Project maintains an archive of snaphots of the (English language) core Linux manual pages that are maintained by Michael Kerrisk. Corrections and additions are welcome, but review the "Help Wanted" list, first.

Man pages belonging to programs are usually distributed together with those programs. Therefore, the core Linux man-pages mainly contains the pages for system calls and library routines, special devices, and file formats. However, it also contains documentation for a few programs, in cases where the authors or maintainers of the program do not distribute man pages themselves.

This page is part of release 3.11 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at


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free - Display amount of free and used memory in the system


free [-b | -k | -m] [-o] [-s delay ] [-t] [-V]


free displays the total amount of free and used physical and swap memory in the system, as well as the buffers used by the kernel. The shared memory column should be ignored; it is obsolete.

The -b switch displays the amount of memory in bytes; the -k switch (set by default) displays it in kilobytes; the -m switch displays it in megabytes.

The -t switch displays a line containing the totals.

The -o switch disables the display of a “buffer adjusted” line. If the -o option is not specified, free subtracts buffer memory from the used memory and adds it to the free memory reported.

The -s switch activates continuous polling delay seconds apart. You may actually specify any floating point number for delay, usleep(3) is used for microsecond resolution delay times.

The -V displays version information.


/proc/meminfo-- memory information

See Also

ps(1) , slabtop(1) , vmstat(8) , top(1)


Written by Brian Edmonds.

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