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Diffstat (limited to 'minislang/slsignal.c')
| -rw-r--r-- | minislang/slsignal.c | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/minislang/slsignal.c b/minislang/slsignal.c new file mode 100644 index 000000000..23863024d --- /dev/null +++ b/minislang/slsignal.c @@ -0,0 +1,346 @@ +/* Copyright (c) 1998 John E. Davis + * This file is part of the S-Lang library. + * + * You may distribute under the terms of either the GNU General Public + * License or the Perl Artistic License. + */ +#include "config.h" +#include "sl-feat.h" + +#include <stdio.h> +#include <signal.h> + +#ifdef HAVE_STDLIB_H +# include <stdlib.h> +#endif + +#ifdef HAVE_UNISTD_H +# include <unistd.h> +#endif + +#ifdef HAVE_SYS_TYPES_H +# include <sys/types.h> +#endif +#ifdef HAVE_SYS_WAIT_H +# include <sys/wait.h> +#endif + +#include <errno.h> + +#include "slang.h" +#include "_slang.h" + +/* Do not trust these environments */ +#if defined(__CYGWIN32__) || defined(__MINGW32__) +# ifdef SLANG_POSIX_SIGNALS +# undef SLANG_POSIX_SIGNALS +# endif +#endif + +/* This function will cause system calls to be restarted after signal if possible */ +SLSig_Fun_Type *SLsignal (int sig, SLSig_Fun_Type *f) +{ +#if defined(SLANG_POSIX_SIGNALS) + struct sigaction old_sa, new_sa; + +# ifdef SIGALRM + /* We want system calls to be interrupted by SIGALRM. */ + if (sig == SIGALRM) return SLsignal_intr (sig, f); +# endif + + sigemptyset (&new_sa.sa_mask); + new_sa.sa_handler = f; + + new_sa.sa_flags = 0; +# ifdef SA_RESTART + new_sa.sa_flags |= SA_RESTART; +# endif + + if (-1 == sigaction (sig, &new_sa, &old_sa)) + return (SLSig_Fun_Type *) SIG_ERR; + + return old_sa.sa_handler; +#else + /* Not POSIX. */ + return signal (sig, f); +#endif +} + +/* This function will NOT cause system calls to be restarted after + * signal if possible + */ +SLSig_Fun_Type *SLsignal_intr (int sig, SLSig_Fun_Type *f) +{ +#ifdef SLANG_POSIX_SIGNALS + struct sigaction old_sa, new_sa; + + sigemptyset (&new_sa.sa_mask); + new_sa.sa_handler = f; + + new_sa.sa_flags = 0; +# ifdef SA_INTERRUPT + new_sa.sa_flags |= SA_INTERRUPT; +# endif + + if (-1 == sigaction (sig, &new_sa, &old_sa)) + return (SLSig_Fun_Type *) SIG_ERR; + + return old_sa.sa_handler; +#else + /* Not POSIX. */ + return signal (sig, f); +#endif +} + +/* We are primarily interested in blocking signals that would cause the + * application to reset the tty. These include suspend signals and + * possibly interrupt signals. + */ +#ifdef SLANG_POSIX_SIGNALS +static sigset_t Old_Signal_Mask; +#endif + +static volatile unsigned int Blocked_Depth; + +int SLsig_block_signals (void) +{ +#ifdef SLANG_POSIX_SIGNALS + sigset_t new_mask; +#endif + + Blocked_Depth++; + if (Blocked_Depth != 1) + { + return 0; + } + +#ifdef SLANG_POSIX_SIGNALS + sigemptyset (&new_mask); +# ifdef SIGQUIT + sigaddset (&new_mask, SIGQUIT); +# endif +# ifdef SIGTSTP + sigaddset (&new_mask, SIGTSTP); +# endif +# ifdef SIGINT + sigaddset (&new_mask, SIGINT); +# endif +# ifdef SIGTTIN + sigaddset (&new_mask, SIGTTIN); +# endif +# ifdef SIGTTOU + sigaddset (&new_mask, SIGTTOU); +# endif + + (void) sigprocmask (SIG_BLOCK, &new_mask, &Old_Signal_Mask); + return 0; +#else + /* Not implemented. */ + return -1; +#endif +} + +int SLsig_unblock_signals (void) +{ + if (Blocked_Depth == 0) + return -1; + + Blocked_Depth--; + + if (Blocked_Depth != 0) + return 0; + +#ifdef SLANG_POSIX_SIGNALS + (void) sigprocmask (SIG_SETMASK, &Old_Signal_Mask, NULL); + return 0; +#else + return -1; +#endif +} + + +#ifdef MSWINDOWS +int SLsystem (char *cmd) +{ + SLang_verror (SL_NOT_IMPLEMENTED, "system not implemented"); + return -1; +} + +#else +int SLsystem (char *cmd) +{ +#ifdef SLANG_POSIX_SIGNALS + pid_t pid; + int status; + struct sigaction ignore; +# ifdef SIGINT + struct sigaction save_intr; +# endif +# ifdef SIGQUIT + struct sigaction save_quit; +# endif +# ifdef SIGCHLD + sigset_t child_mask, save_mask; +# endif + + if (cmd == NULL) return 1; + + ignore.sa_handler = SIG_IGN; + sigemptyset (&ignore.sa_mask); + ignore.sa_flags = 0; + +# ifdef SIGINT + if (-1 == sigaction (SIGINT, &ignore, &save_intr)) + return -1; +# endif + +# ifdef SIGQUIT + if (-1 == sigaction (SIGQUIT, &ignore, &save_quit)) + { + (void) sigaction (SIGINT, &save_intr, NULL); + return -1; + } +# endif + +# ifdef SIGCHLD + sigemptyset (&child_mask); + sigaddset (&child_mask, SIGCHLD); + if (-1 == sigprocmask (SIG_BLOCK, &child_mask, &save_mask)) + { +# ifdef SIGINT + (void) sigaction (SIGINT, &save_intr, NULL); +# endif +# ifdef SIGQUIT + (void) sigaction (SIGQUIT, &save_quit, NULL); +# endif + return -1; + } +# endif + + pid = fork(); + + if (pid == -1) + status = -1; + else if (pid == 0) + { + /* Child */ +# ifdef SIGINT + (void) sigaction (SIGINT, &save_intr, NULL); +# endif +# ifdef SIGQUIT + (void) sigaction (SIGQUIT, &save_quit, NULL); +# endif +# ifdef SIGCHLD + (void) sigprocmask (SIG_SETMASK, &save_mask, NULL); +# endif + + execl ("/bin/sh", "sh", "-c", cmd, NULL); + _exit (127); + } + else + { + /* parent */ + while (-1 == waitpid (pid, &status, 0)) + { +# ifdef EINTR + if (errno == EINTR) + continue; +# endif +# ifdef ERESTARTSYS + if (errno == ERESTARTSYS) + continue; +# endif + status = -1; + break; + } + } +# ifdef SIGINT + if (-1 == sigaction (SIGINT, &save_intr, NULL)) + status = -1; +# endif +# ifdef SIGQUIT + if (-1 == sigaction (SIGQUIT, &save_quit, NULL)) + status = -1; +# endif +# ifdef SIGCHLD + if (-1 == sigprocmask (SIG_SETMASK, &save_mask, NULL)) + status = -1; +# endif + + return status; + +#else /* No POSIX Signals */ +# ifdef SIGINT + void (*sint)(int); +# endif +# ifdef SIGQUIT + void (*squit)(int); +# endif + int status; + +# ifdef SIGQUIT + squit = SLsignal (SIGQUIT, SIG_IGN); +# endif +# ifdef SIGINT + sint = SLsignal (SIGINT, SIG_IGN); +# endif + status = system (cmd); +# ifdef SIGINT + SLsignal (SIGINT, sint); +# endif +# ifdef SIGQUIT + SLsignal (SIGQUIT, squit); +# endif + return status; +#endif /* POSIX_SIGNALS */ +} +#endif + + +#if 0 +#include <windows.h> +static int msw_system (char *cmd) +{ + STARTUPINFO startup_info; + PROCESS_INFORMATION process_info; + int status; + + if (cmd == NULL) return -1; + + memset ((char *) &startup_info, 0, sizeof (STARTUPINFO)); + startup_info.cb = sizeof(STARTUPINFO); + startup_info.dwFlags = STARTF_USESHOWWINDOW; + startup_info.wShowWindow = SW_SHOWDEFAULT; + + if (FALSE == CreateProcess (NULL, + cmd, + NULL, + NULL, + FALSE, + NORMAL_PRIORITY_CLASS|CREATE_NEW_CONSOLE, + NULL, + NULL, + &startup_info, + &process_info)) + { + SLang_verror (0, "%s: CreateProcess failed.", cmd); + return -1; + } + + + status = -1; + + if (0xFFFFFFFFUL != WaitForSingleObject (process_info.hProcess, INFINITE)) + { + DWORD exit_code; + + if (TRUE == GetExitCodeProcess (process_info.hProcess, &exit_code)) + status = (int) exit_code; + } + + CloseHandle (process_info.hThread); + CloseHandle (process_info.hProcess); + + return status; +} +#endif |