---
name: "sig"
section: "3"
platform: "macos"
package: "ksh"
version: "42"
release: "macOS 26.5"
platforms: ["macos"]
url: "https://new.carta.tech/sig"
---

# sig(3)

signal interface routines

## NAME

sig - signal interface routines

## SYNOPSIS

$1$2#include \<ast.h\>#include \<ast.h\>#include \<ast.h\>#include \<ast.h\>#include \<ast.h\>#include \<ast.h\>#include \<ast.h\>#include \<ast.h\> $1$2#include \<sig.h\>#include \<sig.h\>#include \<sig.h\>#include \<sig.h\>#include \<sig.h\>#include \<sig.h\>#include \<sig.h\>#include \<sig.h\>

$1$2int sigunblock(int sig);int sigunblock(int sig);int sigunblock(int sig);int sigunblock(int sig);int sigunblock(int sig);int sigunblock(int sig);int sigunblock(int sig);int sigunblock(int sig); $1$2int sigcritical(int op);int sigcritical(int op);int sigcritical(int op);int sigcritical(int op);int sigcritical(int op);int sigcritical(int op);int sigcritical(int op);int sigcritical(int op);

## DESCRIPTION

$1$2sigunblocksigunblocksigunblocksigunblocksigunblocksigunblocksigunblocksigunblock is called to unblocks the signal $1$2sigsigsigsigsigsigsigsig from within a handler currently servicing $1$2sigsigsigsigsigsigsigsig

$1$2sigcriticalsigcriticalsigcriticalsigcriticalsigcriticalsigcriticalsigcriticalsigcritical controls a critical region for the $1$2SIGINTSIGINTSIGINTSIGINTSIGINTSIGINTSIGINTSIGINT $1$2SIGQUITSIGQUITSIGQUITSIGQUITSIGQUITSIGQUITSIGQUITSIGQUIT and $1$2SIGHUPSIGHUPSIGHUPSIGHUPSIGHUPSIGHUPSIGHUPSIGHUP signals. $1$2op \> 0op \> 0op \> 0op \> 0op \> 0op \> 0op \> 0op \> 0 pushes the region, $1$2op == 0op == 0op == 0op == 0op == 0op == 0op == 0op == 0 pops the region, and $1$2op \< 0op \< 0op \< 0op \< 0op \< 0op \< 0op \< 0op \< 0 returns non-zero if any signals are being held in the current critical region. Signal critical regions may be nested. The current critical region level is returned, $1$2-1-1-1-1-1-1-1-1 on error.

## SEE ALSO

[signal(2)](/signal/2.md)