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Diffstat (limited to 'src/exec.c')
| -rw-r--r-- | src/exec.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/src/exec.c b/src/exec.c new file mode 100644 index 0000000..7e4899d --- /dev/null +++ b/src/exec.c @@ -0,0 +1,190 @@ +/*=========================================================================== + Copyright (c) 1998-2000, The Santa Cruz Operation + All rights reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + + *Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + + *Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimer in the documentation + and/or other materials provided with the distribution. + + *Neither name of The Santa Cruz Operation nor the names of its contributors + may be used to endorse or promote products derived from this software + without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS + IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, + THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE + LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + INTERRUPTION) + HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH + DAMAGE. + =========================================================================*/ + +/* cscope - interactive C symbol cross-reference + * + * process execution functions + */ + +#include <unistd.h> +#include "global.h" +#include <stdarg.h> +#include <sys/wait.h> +#include <sys/types.h> /* pid_t */ +#ifdef __DJGPP__ +#include <process.h> +#endif +#if defined(USE_NCURSES) && !defined(RENAMED_NCURSES) +#include <ncurses.h> +#else +#include <curses.h> +#endif + +static char const rcsid[] = "$Id: exec.c,v 1.10 2006/04/21 10:45:48 broeker Exp $"; + +static sighandler_t oldsigquit; /* old value of quit signal */ +static sighandler_t oldsighup; /* old value of hangup signal */ +static sighandler_t oldsigtstp; /* old value of SIGTSTP */ + +#ifndef __MSDOS__ /* none of these is needed, there */ +static int join(pid_t p); +static int myexecvp(char *a, char **args); +static pid_t myfork(void); +#endif + +/* execute forks and executes a program or shell script, waits for it to + * finish, and returns its exit code. + */ + +/*VARARGS1*/ +int +execute(char *a, ...) /* note: "exec" is already defined on u370 */ +{ + va_list ap; + int exitcode = -1; /* initialize, to avoid warning */ + char *argv[BUFSIZ]; + pid_t p; + + /* fork and exec the program or shell script */ + endwin(); /* restore the terminal modes */ + mousecleanup(); + fflush(stdout); + va_start(ap, a); + for (p = 0; (argv[p] = va_arg(ap, char *)) != 0; p++) + ; +#ifdef __MSDOS__ + /* HBB 20010313: in MSDOG, everything is completely different. + * No fork()/exec()/wait(), but rather a single libc call: */ + exitcode = spawnvp(P_WAIT, a, argv); +#else + if ((p = myfork()) == 0) { + myexecvp(a, argv); /* child */ + } + else { + exitcode = join(p); /* parent */ + } +#endif /* MSDOS */ + + /* the menu and scrollbar may be changed by the command executed */ +#if UNIXPC || !TERMINFO +# ifndef __DJGPP__ /* leave CRLF handling as is */ + nonl(); +# endif + cbreak(); /* endwin() turns off cbreak mode so restore it */ + noecho(); +#endif + mousemenu(); + drawscrollbar(topline, nextline); + va_end(ap); + return(exitcode); +} + +#ifndef __MSDOS__ /* None of the following functions is used there */ + +/* myexecvp is an interface to the execvp system call to + * modify argv[0] to reference the last component of its path-name. + */ +static int +myexecvp(char *a, char **args) +{ + char msg[MSGLEN + 1]; + + /* modify argv[0] to reference the last component of its path name */ + args[0] = mybasename(args[0]); + + /* execute the program or shell script */ + execvp(a, args); /* returns only on failure */ + sprintf(msg, "\nCannot exec %s", a); + perror(msg); /* display the reason */ + askforreturn(); /* wait until the user sees the message */ + myexit(1); /* exit the child */ + /* NOTREACHED */ +} + +/* myfork acts like fork but also handles signals */ + +static pid_t +myfork(void) +{ + pid_t p; /* process number */ + + p = fork(); + + /* the parent ignores the interrupt, quit, and hangup signals */ + if (p > 0) { + oldsigquit = signal(SIGQUIT, SIG_IGN); + oldsighup = signal(SIGHUP, SIG_IGN); +#ifdef SIGTSTP + oldsigtstp = signal(SIGTSTP, SIG_DFL); +#endif + } + /* so they can be used to stop the child */ + else if (p == 0) { + signal(SIGINT, SIG_DFL); + signal(SIGQUIT, SIG_DFL); + signal(SIGHUP, SIG_DFL); +#ifdef SIGTSTP + signal(SIGTSTP, SIG_DFL); +#endif + } + /* check for fork failure */ + if (p == -1) { + myperror("Cannot fork"); + } + return p; +} + +/* join is the compliment of fork */ + +static int +join(pid_t p) +{ + int status; + pid_t w; + + /* wait for the correct child to exit */ + do { + w = wait(&status); + } while (p != -1 && w != p); + + /* restore signal handling */ + signal(SIGQUIT, oldsigquit); + signal(SIGHUP, oldsighup); +#ifdef SIGTSTP + signal(SIGTSTP, oldsigtstp); +#endif + + /* return the child's exit code */ + return(status >> 8); +} + +#endif /* !MSDOS */ |