ProfitPress Mega CDROM2 …eeware (MSDOS)(1992)(Eng)/ProfitPress-MegaCDROM2.B6I/MISC/GNU/PL4019AS.ZIP/POPEN.C

C/C++ Source or Header | 1992-01-30 | 4.2 KB | 220 lines

/* $RCSfile: popen.c,v $$Revision: 4.0.1.1 $$Date: 91/06/07 11:22:52 $
 *
 *    (C) Copyright 1988, 1990 Diomidis Spinellis.
 *
 *    You may distribute under the terms of either the GNU General Public
 *    License or the Artistic License, as specified in the README file.
 *
 * $Log:    popen.c,v $
 * Revision 4.0.1.1  91/06/07  11:22:52  lwall
 * patch4: new copyright notice
 *
 * Revision 4.0  91/03/20  01:34:50  lwall
 * 4.0 baseline.
 *
 * Revision 3.0.1.2  90/08/09  04:04:42  lwall
 * patch19: various MSDOS and OS/2 patches folded in
 *
 * Revision 3.0.1.1  90/03/27  16:11:57  lwall
 * patch16: MSDOS support
 *
 * Revision 1.1  90/03/18  20:32:20  dds
 * Initial revision
 *
 */


/*
 * Popen and pclose for MS-DOS
 */


#include <stdlib.h>
#include <stdio.h>
#include <dir.h>
#include <process.h>


/*
 * Possible actions on an popened file
 */
enum action {
    delete,             /* Used for "r". Delete the tmp file */
    execute                /* Used for "w". Execute the command. */
};


/*
 * Linked list of things to do at the end of the program execution.
 */
struct todo {
    FILE *f;            /* File we are working on (to fclose) */
    const char *name;        /* Name of the file (to unlink) */
    const char *command;        /* Command to execute */
    enum action what;        /* What to do (execute or delete) */
    struct todo *next;        /* Next structure */
} *todolist;




/* Clean up function */
static int close_pipes(void);


/*
 * Add a file f running the command command on file name to the list
 * of actions to be done at the end.  The action is specified in what.
 * Return -1 on failure, 0 if ok.
 */
static int
add(FILE *f, const char *command, const char *name, enum action what)
{
    struct todo    *p;


    if ((p = (struct todo *) malloc(sizeof(struct todo))) == NULL)
        return -1;
    p->f = f;
    p->command = command;
    p->name = name;
    p->what = what;
    p->next = todolist;
    todolist = p;
    return 0;
}


FILE *
mypopen(const char *command, const char *t)
{
    char buff[128];
    char fname[8];
    char *tpath;
    char *name, *tmp_path;
    char sep = '\\';
    FILE *f;
    static init = 0;


    if (!init)
        if (atexit((void (*)())close_pipes) != 0)
            return NULL;
        else
            init++;

    strcpy(fname,"PXXXXXX");

    if ((name = mktemp(fname)) == NULL)
        return NULL;

    if ((tpath = malloc(64)) == NULL)
        return NULL;

    if ((tmp_path = getenv("TMP")) != NULL) {
        if (strchr(tmp_path,'/') != NULL)
            sep = '/';
        else
            sep = '\\';
        sprintf(tpath, "%s%c%s", tmp_path, sep, name);
    } else
        sprintf(tpath, "%s", name);

    name = tpath;


    switch (*t) {
    case 'r':
        sprintf(buff, "%s >%s", command, name);
        if (xsystem(buff) || (f = fopen(name, "r")) == NULL) {
            free(name);
            return NULL;
        }
        if (add(f, command, name, delete)) {
            (void)fclose(f);
            (void)unlink(name);
            free(name);
            return NULL;
        }
        return f;
    case 'w':
        if ((f = fopen(name, "w")) == NULL) {
            free(name);
            return NULL;
        }
        if (add(f, command, name, execute)) {
            (void)fclose(f);
            (void)unlink(name);
            free(name);
            return NULL;
        }
        return f;
    default:
        free(name);
        return NULL;
    }
}


int
mypclose(FILE *f)
{
    struct todo *p, **prev;
    char buff[256];
    const char *name;
    int status;


    for (p = todolist, prev = &todolist; p; prev = &(p->next), p = p->next)
        if (p->f == f) {
            *prev = p->next;
            name = p->name;
            switch (p->what) {
            case delete:
                free(p);
                if (fclose(f) == EOF) {
                    (void)unlink(name);
                    status = EOF;
                } else if (unlink(name) < 0)
                    status = EOF;
                else
                    status = 0;
                free((void*)name);
                return status;
            case execute:
                (void)sprintf(buff, "%s <%s", p->command, p->name);
                free(p);
                if (fclose(f) == EOF) {
                    (void)unlink(name);
                    status = EOF;
                } else if (xsystem(buff)) {
                    (void)unlink(name);
                    status = EOF;
                } else if (unlink(name) < 0)
                    status = EOF;
                else
                    status = 0;
                free((void*)name);
                return status;
            default:
                return EOF;
            }
        }
    return EOF;
}


/*
 * Clean up at the end.  Called by the onexit handler.
 */
static int
close_pipes(void)
{
    struct todo    *p;


    for (p = todolist; p; p = p->next)
        (void)mypclose(p->f);
    return 0;
}