/*
 * m_mktemp.c -- Construct a temporary file.
 *
 * $Id: m_mktemp.c,v 1.4 2002/07/02 22:09:14 kenh Exp $
 *
 * This code is Copyright (c) 2010, by the authors of nmh.  See the
 * COPYRIGHT file in the root directory of the nmh distribution for
 * complete copyright information.
 */

#include <errno.h>
#include <h/mh.h>


char *
m_mktemp (
    const char *pfx_in,   /* Pathname prefix for temporary file. */
    int *fd_ret,          /* (return,optional) File descriptor to temp file. */
    FILE **fp_ret         /* (return,optional) FILE pointer to temp file. */
)
{
    static char tmpfil[BUFSIZ];
    const char *pfx = (pfx_in == NULL) ? "/tmp/nmh" : pfx_in;
    int fd = -1;
    int keep_open = 0;

    snprintf(tmpfil, sizeof(tmpfil), "%sXXXXXX", pfx);
    fd = mkstemp(tmpfil);
    if (fd < 0) {
        return NULL;
    }
    if (fd_ret != NULL) {
        *fd_ret = fd;
        keep_open = 1;
    }
    if (fp_ret != NULL) {
        FILE *fp = fdopen(fd, "w+");
        if (fp == NULL) {
            int olderr = errno;
            unlink(tmpfil);
            close(fd);
            errno = olderr;
            return NULL;
        }
        *fp_ret = fp;
        keep_open = 1;
    }
    if (!keep_open) {
        close(fd);
    }
    return tmpfil;
}

/* This version allows one to specify the directory the temp file should
 * by created based on a given pathname.  The pfx_in parameter specifies
 * a basename prefix for the file.  If dir_in is NULL, then the system
 * temporary directory will be used for containing the temporary file.
 */
char *
m_mktemp2 (
    const char *dir_in,   /* Directory to place temp file. */
    const char *pfx_in,   /* Basename prefix for temp file. */
    int *fd_ret,          /* (return,optional) File descriptor to temp file. */
    FILE **fp_ret         /* (return,optional) FILE pointer to temp file. */
)
{
    static char buffer[BUFSIZ];
    char *cp;

    if (dir_in == NULL) {
        if (pfx_in == NULL) {
            return m_mktemp(NULL, fd_ret, fp_ret);
        }
        snprintf(buffer, sizeof(buffer), "/tmp/%s", pfx_in);
        return m_mktemp(buffer, fd_ret, fp_ret);
    }

    if ((cp = r1bindex ((char *)dir_in, '/')) == dir_in) {
        /* No directory component */
        return m_mktemp(pfx_in, fd_ret, fp_ret);
    }
    int n = (int)(cp-dir_in-1); /* Length of dir component */
    snprintf(buffer, sizeof(buffer), "%.*s%s", n, dir_in, pfx_in);
    return m_mktemp(buffer, fd_ret, fp_ret);
}