Java example source code file (exec_md.c)

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Java - Java tags/keywords

fork, null, sys_err, sys_nomem, sys_ok

The exec_md.c Java example source code

/*
 * Copyright (c) 1998, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include "sys.h"
#include "util.h"

#if defined(LINUX) || defined(_ALLBSD_SOURCE)
  /* Linux */
  #define FORK() fork()
#else
  /* Solaris (make sure we always get the POSIX-specified behavior) */
  #define FORK() fork1()
#endif

static char *skipWhitespace(char *p) {
    while ((*p != '\0') && isspace(*p)) {
        p++;
    }
    return p;
}

static char *skipNonWhitespace(char *p) {
    while ((*p != '\0') && !isspace(*p)) {
        p++;
    }
    return p;
}

int
dbgsysExec(char *cmdLine)
{
    int i;
    int argc;
    pid_t pid_err = (pid_t)(-1); /* this is the error return value */
    pid_t pid;
    char **argv = NULL;
    char *p;
    char *args;

    /* Skip leading whitespace */
    cmdLine = skipWhitespace(cmdLine);

    /*LINTED*/
    args = jvmtiAllocate((jint)strlen(cmdLine)+1);
    if (args == NULL) {
        return SYS_NOMEM;
    }
    (void)strcpy(args, cmdLine);

    p = args;

    argc = 0;
    while (*p != '\0') {
        p = skipNonWhitespace(p);
        argc++;
        if (*p == '\0') {
            break;
        }
        p = skipWhitespace(p);
    }

    /*LINTED*/
    argv = jvmtiAllocate((argc + 1) * (jint)sizeof(char *));
    if (argv == 0) {
        jvmtiDeallocate(args);
        return SYS_NOMEM;
    }

    for (i = 0, p = args; i < argc; i++) {
        argv[i] = p;
        p = skipNonWhitespace(p);
        *p++ = '\0';
        p = skipWhitespace(p);
    }
    argv[i] = NULL;  /* NULL terminate */

    if ((pid = FORK()) == 0) {
        /* Child process */
        int i;
        long max_fd;

        /* close everything */
        max_fd = sysconf(_SC_OPEN_MAX);
        /*LINTED*/
        for (i = 3; i < (int)max_fd; i++) {
            (void)close(i);
        }

        (void)execvp(argv[0], argv);

        exit(-1);
    }
    jvmtiDeallocate(args);
    jvmtiDeallocate(argv);
    if (pid == pid_err) {
        return SYS_ERR;
    } else {
        return SYS_OK;
    }
}