/***
*spawnve.c - OS/2 low level routine eventually called by all _spawnXX routines
* also contains all code for _execve, called by _execXX routines
*
* Copyright (c) 1985-1992, Microsoft Corporation. All rights reserved.
*
*Purpose:
*
* This is the low level routine which is eventually invoked by all the
* _spawnXX routines.
*
* This is also the low-level routine which is eventually invoked by
* all of the _execXX routines.
*
*Revision History:
* 03-??-84 RLB created
* 05-??-84 DCW modified to fix bug in initialization of envblock
* pointer (used int 0 which would fail in long model) and
* changed (char *)0 to NULL.
* 03-31-86 SKS modified for OS/2; no OVERLAY mode,
* new format for DOS Exec function
* also check for Xenix or DOS style slash characters
* 10-13-86 SKS pass program name to _cenvarg()
* 11-19-86 SKS handle both kinds of slashes, with support for Kanji
* 01-29-87 BCM don't try ".com" extension in protected mode (OS/2)
* 12-11-87 JCR Added "_LOAD_DS" to declaration
* 05/31/88 SJM Re-written to allow spawn of .CMD files, increase
* speed. Added comexecmd routine.
* 06/01/88 SJM added #ifdef statements for execve.obj compilation
* 10-30-88 GJF Call _dospawn() for EXECVE, not _doexec().
* 07-21-89 GJF Progagated fixes of 11-23-88 and 05-27-89 from CRT tree.
* 11-16-89 GJF Added code to execve/spawnve to ensure a relative or
* or absolute pathname is always used for the executable,
* not just a filename (otherwise DOSEXECPGM will search
* the PATH!). Also, cleaned up some of the erratic
* formatting. Same as 9-15-89 change to CRT version
* 11-20-89 GJF Added const attribute to types of appropriate args.
* 02-08-90 GJF Fixed bug in comexecmd (must free(comname) if and only
* if comname points to a malloc-ed block). Propagated
* from 02-07-90 change in crt6 version.
* 03-08-90 GJF Replaced _LOAD_DS with _CALLTYPE1, added #include
* <cruntime.h> and removed #include <register.h>.
* 04-02-90 GJF Made comexecmd() _CALLTYPE4. Added #include <io.h>
* and a prototype for comexecmd() to fix compiler
* warnings (-W3).
* 05-21-90 GJF Fixed stack checking pragma syntax.
* 07-24-90 SBM Removed redundant include, minor optimization
* 09-27-90 GJF New-style function declarators.
* 12-28-90 SRW Added _CRUISER_ conditional around check_stack pragma
* 01-17-91 GJF ANSI naming.
* 08-21-91 JCR Call access() in before comexecmd (bug fix)
* 01-24-92 JCR upgraded for Win32
* 10-24-92 SKS Remove special treatment for batch files -
* Windows NT will spawn %COMSPEC% automatically
* 11-30-92 KRS Ported _MBCS support from 16-bit tree.
*
*******************************************************************************/
#include <cruntime.h>
#include <io.h>
#include <process.h>
#include <errno.h>
#include <msdos.h>
#include <string.h>
#include <stdlib.h>
#include <internal.h>
#include <mbstring.h>
#ifdef _CRUISER_
#pragma check_stack(on) /* turn on stack checking */
#endif /* ndef _CRUISER_ */
#define SLASHCHAR '\\'
#define XSLASHCHAR '/'
#ifndef EXECVE
static int _CALLTYPE4 comexecmd(int mode, const char * name,
const char * const * argv, const char * const * envp);
#else
static int _CALLTYPE4 comexecmd(const char * name,
const char * const * argv, const char * const * envp);
#endif /* EXECVE */
/***
*static int comexecmd(mode, name, argv, envp) - do the exec
* or spawn after name fixup
*
*Purpose:
* Spawns a child process with given parameters and environment. Either
* overlays current process or loads in free memory while parent process
* waits. If the named file is a .cmd file, modifies the calling sequence
* and prepends the /c and filename arguments into the command string
*
* Exec doesn't take a mode; instead, the parent process goes away as
* the child process is brought in.
*
*Entry:
* int mode - mode to spawn (WAIT, NOWAIT, or OVERLAY)
* only WAIT and OVERLAY currently supported
*
* **** mode is only used in the spawnve() version ****
*
* char *name - pathname of file to spawn. Includes the extension
* char **argv - vector of parameter strings
* char **envp - vector of environment variables
*
*Exit:
* returns exit code of child process
* if fails, returns -1
*
*Exceptions:
* Returns a value of (-1) to indicate an error in exec'ing the child
* process. errno may be set to:
*
* E2BIG = failed in argument/environment processing (_cenvarg)
* argument list or environment too big;
* EACCESS = locking or sharing violation on file;
* EMFILE = too many files open;
* ENOENT = failed to find program name - no such file or directory;
* ENOEXEC = failed in exec - bad executable format;
* ENOMEM = failed in memory allocation (during malloc, or in
* setting up memory for executing child process).
*
*******************************************************************************/
static int _CALLTYPE4 comexecmd (
#ifndef EXECVE
REG3 int mode,
#endif /* EXECVE */
REG2 const char *name,
const char * const *argv,
const char * const *envp
)
{
char *argblk;
char *envblk;
REG4 int rc;
if (_cenvarg(argv, envp, &argblk, &envblk, name) == -1)
return -1;
#ifndef EXECVE
rc = _dospawn(mode, name, argblk, envblk);
#else
rc = _dospawn(_P_OVERLAY, name, argblk, envblk);
#endif
/* free memory */
free(argblk);
free(envblk);
return rc;
}
/***
*int _spawnve(mode, name, argv, envp) - low level _spawnXX library function
*int _execve(name, argv, envp) - low level _execXX library function
*
*Purpose:
* spawns or execs a child process; takes a single pointer to an argument
* list as well as a pointer to the environment; unlike _spawnvpe,
* _spawnve does not search the PATH= list in processing the name
* parameter; mode specifies the parent's execution mode.
*
*Entry:
* int mode - parent process's execution mode:
* must be one of _P_OVERLAY, _P_WAIT, _P_NOWAIT;
* not used for _execve
* char *name - path name of program to spawn;
* char **argv - pointer to array of pointers to child's arguments;
* char **envp - pointer to array of pointers to child's environment
* settings.
*
*Exit:
* Returns : (int) a status value whose meaning is as follows:
* 0 = normal termination of child process;
* positive = exit code of child upon error termination
* (abort or exit(nonzero));
* -1 = child process was not spawned;
* errno indicates what kind of error:
* (E2BIG, EINVAL, ENOENT, ENOEXEC, ENOMEM).
*
*Exceptions:
* Returns a value of (-1) to indicate an error in spawning the child
* process. errno may be set to:
*
* E2BIG = failed in argument/environment processing (_cenvarg) -
* argument list or environment too big;
* EINVAL = invalid mode argument;
* ENOENT = failed to find program name - no such file or directory;
* ENOEXEC = failed in spawn - bad executable format;
* ENOMEM = failed in memory allocation (during malloc, or in
* setting up memory for spawning child process).
*
*******************************************************************************/
/* Extension array - ordered in search order from right to left.
ext_strings = array of extensions
*/
#ifdef _CRUISER_
static char *ext_strings[] = { NULL, ".exe", ".com" };
enum {CMD, EXE, COM, EXTFIRST=CMD, EXTLAST=COM};
#else
static char *ext_strings[] = { ".cmd", ".bat", ".exe" , ".com" };
enum {CMD, BAT, EXE, COM, EXTFIRST=CMD, EXTLAST=COM};
#endif
int _CALLTYPE1
#ifndef EXECVE
_spawnve (
REG3 int mode,
#else
_execve (
#endif /* EXECVE */
const char *name,
const char * const *argv,
const char * const *envp
)
{
char *ext; /* where the extension goes if we have to add one */
REG1 char *p;
char *q;
REG2 char *pathname = (char *)name;
REG4 int rc;
REG5 int i;
#ifdef _CRUISER_
exstrings[CMD] = _osmode ? ".cmd" : ".bat";
#endif
p = _mbsrchr(pathname, SLASHCHAR);
q = strrchr(pathname, XSLASHCHAR); /* No need for _mbsrchr with "/" */
/* ensure that pathname is an absolute or relative pathname. also,
* position p to point at the filename portion of pathname (i.e., just
* after the last occurence of a colon, slash or backslash character */
if (!q) {
if (!p)
if (!(p = strchr(pathname, ':'))) {
/* pathname is a filename only, force it to be
* a relative pathname. note that an extra byte
* is malloc-ed just in case pathname is NULL,
* to keep the heap from being trashed by
* strcpy */
if (!(pathname = malloc(strlen(pathname) + 3)))
return(-1);
strcpy(pathname, ".\\");
strcat(pathname, name);
/* set p to point to the start of the filename
* (i.e., past the ".\\" prefix) */
p = pathname + 2;
}
/* else pathname has drive specifier prefix and p is
* is pointing to the ':' */
}
else if (!p || q > p) /* p == NULL or q > p */
p = q;
rc = -1; /* init to error value */
if (ext = strrchr(p, '.')) {
/* extension given; only do filename */
if (_access(pathname, 0) != -1) {
#ifndef EXECVE
rc = comexecmd(mode, pathname, argv, envp);
#else
rc = comexecmd(pathname, argv, envp);
#endif
}
}
else {
/* no extension; try .cmd/.bat, then .com and .exe */
if (!(p = malloc(strlen(pathname) + 5)))
return(-1);
strcpy(p, pathname);
ext = p + strlen(pathname);
for (i = EXTLAST; i >= EXTFIRST; --i) {
strcpy(ext, ext_strings[i]);
if (_access(p, 0) != -1) {
#ifndef EXECVE
rc = comexecmd(mode, p, argv, envp);
#else
rc = comexecmd(p, argv, envp);
#endif /* EXECVE */
break;
}
}
free(p);
}
if (pathname != name)
free(pathname);
return rc;
}
