gtags-cscope/mypopen.c

gtags-cscope/mypopen.c
/* */
This source file includes following definitions.
myopen
myfopen
mypopen
mypclose
   1 /*===========================================================================
   2  Copyright (c) 1998-2000, The Santa Cruz Operation 
   3  All rights reserved.
   4  
   5  Redistribution and use in source and binary forms, with or without
   6  modification, are permitted provided that the following conditions are met:
   7 
   8  *Redistributions of source code must retain the above copyright notice,
   9  this list of conditions and the following disclaimer.
  10 
  11  *Redistributions in binary form must reproduce the above copyright notice,
  12  this list of conditions and the following disclaimer in the documentation
  13  and/or other materials provided with the distribution.
  14 
  15  *Neither name of The Santa Cruz Operation nor the names of its contributors
  16  may be used to endorse or promote products derived from this software
  17  without specific prior written permission. 
  18 
  19  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
  20  IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  21  THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
  23  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  INTERRUPTION)
  27  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  30  DAMAGE. 
  31  =========================================================================*/
  32 
  33 #include <stdio.h>
  34 #include <signal.h>
  35 #include <unistd.h>
  36 #include <fcntl.h>
  37 #include <sys/types.h>
  38 #include "global-cscope.h"      /* pid_t, RETSIGTYPE, shell, and mybasename() */
  39 
  40 #if defined(__DJGPP__) || (defined(_WIN32) && !defined(__CYGWIN__))
  41 #define MS_OS
  42 #else
  43 #include <sys/wait.h>
  44 #endif
  45 
  46 #define tst(a,b) (*mode == 'r'? (b) : (a))
  47 #define RDR     0
  48 #define WTR     1
  49 
  50 /* HBB 20010312: make this a bit safer --- don't blindly assume it's 1 */
  51 #ifdef FD_CLOEXEC
  52 # define CLOSE_ON_EXEC FD_CLOEXEC
  53 #else
  54 # define CLOSE_ON_EXEC 1
  55 #endif
  56 
  57 #ifdef HAVE_IO_H
  58 # include <io.h>                /* for setmode() */
  59 #endif
  60 
  61 static char const rcsid[] = "$Id: mypopen.c,v 1.3 2012/10/13 07:02:07 shigio Exp $";
  62 
  63 static pid_t popen_pid[20];
  64 static RETSIGTYPE (*tstat)(int);
  65 
  66 /** opens a file descriptor and then sets close-on-exec for the file */
  67 int
  68 myopen(char *path, int flag, int mode)
  69 {
  70     /* opens a file descriptor and then sets close-on-exec for the file */
  71     int fd;
  72 
  73     /* 20020103: if file is not explicitly in Binary mode, make
  74      * sure we override silly Cygwin behaviour of automatic binary
  75      * mode for files in "binary mounted" paths */
  76 #if O_BINARY != O_TEXT
  77     if (! (flag | O_BINARY))
  78         flag |= O_TEXT;
  79 #endif
  80     if(mode)
  81         fd = open(path, flag, mode);
  82     else
  83         fd = open(path, flag);
  84 
  85 #ifdef MS_OS                    /* FIXME: test feature, not platform */
  86     /* HBB 20010312: DOS GCC doesn't have FD_CLOEXEC (yet), so it 
  87      * always fails this call. Have to skip that step */
  88     if(fd != -1)
  89         return(fd);
  90 #else
  91     if(fd != -1 && (fcntl(fd, F_SETFD, CLOSE_ON_EXEC) != -1))
  92         return(fd);
  93 #endif
  94     else
  95         {
  96             /* Ensure that if the fcntl fails and fd is valid, then
  97                the file is closed properly. In general this should
  98                not happen. */
  99             if (fd != -1)
 100                 {
 101                     close (fd);
 102                 }
 103 
 104             return(-1);
 105         }
 106 }
 107 
 108 /** opens a file pointer and then sets close-on-exec for the file */
 109 FILE *
 110 myfopen(char *path, char *mode)
 111 {
 112     /* opens a file pointer and then sets close-on-exec for the file */
 113     FILE *fp;
 114 
 115     fp = fopen(path, mode);
 116 
 117 #ifdef SETMODE
 118     if (fp && ! strchr(mode, 'b')) {
 119         SETMODE(fileno(fp), O_TEXT);
 120     }
 121 #endif /* SETMODE */
 122         
 123 #ifdef MS_OS     /* FIXME: test feature, not platform */
 124     /* HBB 20010312: DOS GCC doesn't have FD_CLOEXEC (yet), so it 
 125      * always fails this call. Have to skip that step */
 126     if(fp)
 127 #else
 128         if(fp && (fcntl(fileno(fp), F_SETFD, CLOSE_ON_EXEC) != -1))
 129 #endif
 130             return(fp);
 131 
 132         else
 133             return(NULL);
 134 }
 135 
 136 FILE *
 137 mypopen(char *cmd, char *mode)
 138 {
 139 #ifdef MS_OS
 140         /* HBB 20010312: Has its own implementation of popen(), which
 141          * is better suited to the platform than cscope's */
 142         return (popen)(cmd, mode);
 143 #else
 144         int     p[2];
 145         pid_t *poptr;
 146         int myside, yourside;
 147         pid_t pid;
 148 
 149         if(pipe(p) < 0)
 150                 return(NULL);
 151         myside = tst(p[WTR], p[RDR]);
 152         yourside = tst(p[RDR], p[WTR]);
 153         if((pid = fork()) == 0) {
 154                 /* myside and yourside reverse roles in child */
 155                 int     stdio;
 156 
 157                 /* close all pipes from other popen's */
 158                 for (poptr = popen_pid; poptr < popen_pid+20; poptr++) {
 159                         if(*poptr)
 160                                 (void) close(poptr - popen_pid);
 161                 }
 162                 stdio = tst(0, 1);
 163                 close(myside);
 164                 close(stdio);
 165 #if V9
 166                 dup2(yourside, stdio);
 167 #else
 168                 fcntl(yourside, F_DUPFD, stdio);
 169 #endif
 170                 close(yourside);
 171                 execlp(shell, mybasename(shell), "-c", cmd, (void *)0);
 172                 _exit(1);
 173         } else if (pid > 0)
 174                 tstat = signal(SIGTSTP, SIG_DFL);
 175         if(pid == -1)
 176                 return(NULL);
 177         popen_pid[myside] = pid;
 178         (void) close(yourside);
 179         return(fdopen(myside, mode));
 180 #endif /* MS_OS */
 181 }
 182 
 183 /* HBB 20010705: renamed from 'pclose', which would collide with
 184  * system-supplied function of same name */
 185 int
 186 mypclose(FILE *ptr)
 187 {
 188         int f;
 189         pid_t r;
 190         int status;
 191         sighandler_t hstat, istat, qstat;
 192 
 193 #ifdef MS_OS
 194         /* HBB 20010705: This system has its own pclose(), which we
 195          * don't want to replace */
 196         return (pclose)(ptr);
 197 #else
 198         f = fileno(ptr);
 199         (void) fclose(ptr);
 200         istat = signal(SIGINT, SIG_IGN);
 201         qstat = signal(SIGQUIT, SIG_IGN);
 202         hstat = signal(SIGHUP, SIG_IGN);
 203         while((r = wait(&status)) != popen_pid[f] && r != -1)
 204                 ;
 205         if(r == -1)
 206                 status = -1;
 207         (void) signal(SIGINT, istat);
 208         (void) signal(SIGQUIT, qstat);
 209         (void) signal(SIGHUP, hstat);
 210         (void) signal(SIGTSTP, tstat);
 211         /* mark this pipe closed */
 212         popen_pid[f] = 0;
 213         return(status);
 214 #endif /* MS_OS */
 215 }
/* */
root/gtags-cscope/mypopen.c

DEFINITIONS
