/*
** Copyright (c) 2010 D. Richard Hipp
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of the Simplified BSD License (also
** known as the "2-Clause License" or "FreeBSD License".)
** This program is distributed in the hope that it will be useful,
** but without any warranty; without even the implied warranty of
** merchantability or fitness for a particular purpose.
**
** Author contact information:
** drh@hwaci.com
** http://www.hwaci.com/drh/
**
*******************************************************************************
**
** This file contains an implementation of a bi-directional popen().
*/
#include "config.h"
#include "popen.h"
#ifdef _WIN32
#include <windows.h>
#include <fcntl.h>
/*
** Print a fatal error and quit.
*/
static void win32_fatal_error(const char *zMsg){
fossil_fatal("%s", zMsg);
}
#else
#include <signal.h>
#include <sys/wait.h>
#endif
/*
** The following macros are used to cast pointers to integers and
** integers to pointers. The way you do this varies from one compiler
** to the next, so we have developed the following set of #if statements
** to generate appropriate macros for a wide range of compilers.
**
** The correct "ANSI" way to do this is to use the intptr_t type.
** Unfortunately, that typedef is not available on all compilers, or
** if it is available, it requires an #include of specific headers
** that vary from one machine to the next.
**
** This code is copied out of SQLite.
*/
#if defined(__PTRDIFF_TYPE__) /* This case should work for GCC */
# define INT_TO_PTR(X) ((void*)(__PTRDIFF_TYPE__)(X))
# define PTR_TO_INT(X) ((int)(__PTRDIFF_TYPE__)(X))
#elif !defined(__GNUC__) /* Works for compilers other than LLVM */
# define INT_TO_PTR(X) ((void*)&((char*)0)[X])
# define PTR_TO_INT(X) ((int)(((char*)X)-(char*)0))
#elif defined(HAVE_STDINT_H) /* Use this case if we have ANSI headers */
# define INT_TO_PTR(X) ((void*)(intptr_t)(X))
# define PTR_TO_INT(X) ((int)(intptr_t)(X))
#else /* Generates a warning - but it always works */
# define INT_TO_PTR(X) ((void*)(X))
# define PTR_TO_INT(X) ((int)(X))
#endif
#ifdef _WIN32
/*
** On windows, create a child process and specify the stdin, stdout,
** and stderr channels for that process to use.
**
** Return the number of errors.
*/
static int win32_create_child_process(
wchar_t *zCmd, /* The command that the child process will run */
HANDLE hIn, /* Standard input */
HANDLE hOut, /* Standard output */
HANDLE hErr, /* Standard error */
DWORD *pChildPid /* OUT: Child process handle */
){
STARTUPINFOW si;
PROCESS_INFORMATION pi;
BOOL rc;
memset(&si, 0, sizeof(si));
si.cb = sizeof(si);
si.dwFlags = STARTF_USESTDHANDLES;
SetHandleInformation(hIn, HANDLE_FLAG_INHERIT, TRUE);
si.hStdInput = hIn;
SetHandleInformation(hOut, HANDLE_FLAG_INHERIT, TRUE);
si.hStdOutput = hOut;
SetHandleInformation(hErr, HANDLE_FLAG_INHERIT, TRUE);
si.hStdError = hErr;
rc = CreateProcessW(
NULL, /* Application Name */
zCmd, /* Command-line */
NULL, /* Process attributes */
NULL, /* Thread attributes */
TRUE, /* Inherit Handles */
0, /* Create flags */
NULL, /* Environment */
NULL, /* Current directory */
&si, /* Startup Info */
&pi /* Process Info */
);
if( rc ){
CloseHandle( pi.hProcess );
CloseHandle( pi.hThread );
*pChildPid = pi.dwProcessId;
}else{
win32_fatal_error("cannot create child process");
}
return rc!=0;
}
#endif
/*
** Create a child process running shell command "zCmd". *ppOut is
** a FILE that becomes the standard input of the child process.
** (The caller writes to *ppOut in order to send text to the child.)
** *ppIn is stdout from the child process. (The caller
** reads from *ppIn in order to receive input from the child.)
** Note that *ppIn is an unbuffered file descriptor, not a FILE.
** The process ID of the child is written into *pChildPid.
**
** Return the number of errors.
*/
int popen2(const char *zCmd, int *pfdIn, FILE **ppOut, int *pChildPid){
#ifdef _WIN32
HANDLE hStdinRd, hStdinWr, hStdoutRd, hStdoutWr, hStderr;
SECURITY_ATTRIBUTES saAttr;
DWORD childPid = 0;
int fd;
saAttr.nLength = sizeof(saAttr);
saAttr.bInheritHandle = TRUE;
saAttr.lpSecurityDescriptor = NULL;
hStderr = GetStdHandle(STD_ERROR_HANDLE);
if( !CreatePipe(&hStdoutRd, &hStdoutWr, &saAttr, 4096) ){
win32_fatal_error("cannot create pipe for stdout");
}
SetHandleInformation( hStdoutRd, HANDLE_FLAG_INHERIT, FALSE);
if( !CreatePipe(&hStdinRd, &hStdinWr, &saAttr, 4096) ){
win32_fatal_error("cannot create pipe for stdin");
}
SetHandleInformation( hStdinWr, HANDLE_FLAG_INHERIT, FALSE);
win32_create_child_process(fossil_utf8_to_unicode(zCmd),
hStdinRd, hStdoutWr, hStderr,&childPid);
*pChildPid = childPid;
*pfdIn = _open_osfhandle(PTR_TO_INT(hStdoutRd), 0);
fd = _open_osfhandle(PTR_TO_INT(hStdinWr), 0);
*ppOut = _fdopen(fd, "w");
CloseHandle(hStdinRd);
CloseHandle(hStdoutWr);
return 0;
#else
int pin[2], pout[2];
*pfdIn = 0;
*ppOut = 0;
*pChildPid = 0;
if( pipe(pin)<0 ){
return 1;
}
if( pipe(pout)<0 ){
close(pin[0]);
close(pin[1]);
return 1;
}
*pChildPid = fork();
if( *pChildPid<0 ){
close(pin[0]);
close(pin[1]);
close(pout[0]);
close(pout[1]);
*pChildPid = 0;
return 1;
}
signal(SIGPIPE,SIG_IGN);
if( *pChildPid==0 ){
int fd;
int nErr = 0;
/* This is the child process */
close(0);
fd = dup(pout[0]);
if( fd!=0 ) nErr++;
close(pout[0]);
close(pout[1]);
close(1);
fd = dup(pin[1]);
if( fd!=1 ) nErr++;
close(pin[0]);
close(pin[1]);
execl("/bin/sh", "/bin/sh", "-c", zCmd, (char*)0);
return 1;
}else{
/* This is the parent process */
close(pin[1]);
*pfdIn = pin[0];
close(pout[0]);
*ppOut = fdopen(pout[1], "w");
return 0;
}
#endif
}
/*
** Close the connection to a child process previously created using
** popen2().
*/
void pclose2(int fdIn, FILE *pOut, int childPid){
#ifdef _WIN32
/* Not implemented, yet */
close(fdIn);
fclose(pOut);
#else
close(fdIn);
fclose(pOut);
while( waitpid(0, 0, WNOHANG)>0 ) {}
#endif
}