CLOSEFROM(2)

✨ NAME ✨

closefrom, close_range — delete open file descriptors 💅

okay so bestie, this is the manual page for closefrom(2) and close_range(2) — they're literally the "bye bye file descriptors" girlies 👋✨

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🎀 LIBRARY 🎀

Standard C Library (libc, -lc) — she lives there, no cap 🫶

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🦋 SYNOPSIS 🦋

#include <unistd.h>

void
closefrom(int lowfd);

int
close_range(u_int lowfd, u_int highfd, int flags);

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🌸 DESCRIPTION 🌸

Okay so first up: closefrom() is a system call that deletes all open file descriptors greater than or equal to lowfd from the per-process object reference table. That's it, that's the whole vibe ✨ any errors encountered while closing file descriptors are ignored — she's unbothered, she's thriving, she does not care 💅

Then we have close_range(), which deletes all open file descriptors between lowfd and highfd inclusive, clamped to the range of open file descriptors. Same energy: any errors encountered while closing file descriptors are ignored, periodt 😌

The supported flags are:

• CLOSE_RANGE_CLOEXEC — set the close-on-exec flag on descriptors in the range instead of closing them 🔥
• CLOSE_RANGE_CLOFORK — set the close-on-fork flag on descriptors in the range instead of closing them 🌈

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⭐ RETURN VALUES ⭐

Upon successful completion, close_range() returns a value of 0. Otherwise, a value of -1 is returned and the global variable errno is set to indicate the error. (Yes bestie, <italic>errno</italic> is literally the main character of error reporting 🎀)

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💀 ERRORS 💀

The close_range() system call will fail if:

• [EINVAL] — the highfd argument is lower than the lowfd argument. not her getting the order wrong 😭
• [EINVAL] — an invalid flag was set. nope, not on the list, not today 🙈

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💖 SEE ALSO 💖

• close(2) — the og, the blueprint, we stan 👑

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🧚 HISTORY 🧚

• The closefrom() function first appeared in FreeBSD 8.0.
• The close_range() function first appeared in FreeBSD 12.2.
• The CLOSE_RANGE_CLOFORK flag appeared in FreeBSD 15.0.

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okay that's the whole page bestie, hope it slayed 💅 this little drop came from the Debian fam, dated October 27, 2025 — mwah, take care, and remember: close your fds before they close you 🫶✨