lib/libcmd/mktemp.c

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1992-2012 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                 Eclipse Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*          http://www.eclipse.org/org/documents/epl-v10.html           *
*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                  David Korn <dgk@research.att.com>                   *
*                                                                      *
***********************************************************************/
#pragma prototyped

static const char usage[] =
"[-?\n@(#)$Id: mktemp (AT&T Research) 2010-03-05 $\n]"
USAGE_LICENSE
"[+NAME?mktemp - make temporary file or directory]"
"[+DESCRIPTION?\bmktemp\b creates a temporary file with optional base "
    "name prefix \aprefix\a. If \aprefix\a is omitted then \btmp_\b is used "
    "and \b--tmp\b is implied. If \aprefix\a contains a directory prefix "
    "then that directory overrides any of the directories described below. A "
    "temporary file will have mode \brw-------\b and a temporary directory "
    "will have mode \brwx------\b, subject to \bumask\b(1). Generated paths "
    "have these attributes:]"
    "{"
        "[+*?Lower case to avoid clashes on case ignorant filesystems.]"
        "[+*?Pseudo-random part to deter denial of service attacks.]"
        "[+*?Default pseudo-random part (no specific \bX...\b template) "
            "formatted to accomodate 8.3 filesystems.]"
    "}"
"[+?A consecutive trailing sequence of \bX\b's in \aprefix\a is replaced "
    "by the pseudo-random part. If there are no \bX\b's then the "
    "pseudo-random part is appended to the prefix.]"
"[d:directory?Create a directory instead of a regular file.]"
"[m:mode]:[mode?Set the mode of the created temporary to \amode\a. "
    "\amode\a is symbolic or octal mode as in \bchmod\b(1). Relative modes "
    "assume an initial mode of \bu=rwx\b.]"
"[p:default?Use \adirectory\a if the \bTMPDIR\b environment variable is "
    "not defined. Implies \b--tmp\b.]:[directory]"
"[q:quiet?Suppress file and directory error diagnostics.]"
"[R:regress?The pseudo random generator is seeded with \aseed\a instead "
    "of process/system specific transient data. Use for testing "
    "only. A seed of \b0\b is silently changed to \b1\b.]#[seed]"
"[t:tmp|temporary-directory?Create a path rooted in a temporary "
    "directory.]"
"[u:unsafe|dry-run?Check for file/directory existence but do not create. "
    "Use this for testing only.]"
"\n"
"\n[ prefix ]\n"
"\n"
"[+SEE ALSO?\bmkdir\b(1), \bpathtemp\b(3), \bmktemp\b(3)]"
;

#include <cmd.h>
#include <ls.h>

int
b_mktemp(int argc, char** argv, Shbltin_t* context)
{
    mode_t      mode = 0;
    mode_t      mask;
    int     fd;
    int     i;
    int     quiet = 0;
    int     unsafe = 0;
    int*        fdp = &fd;
    char*       dir = "";
    char*       pfx;
    char*       t;
    char        path[PATH_MAX];

    cmdinit(argc, argv, context, ERROR_CATALOG, ERROR_NOTIFY);
    for (;;)
    {
        switch (optget(argv, usage))
        {
        case 'd':
            fdp = 0;
            continue;
        case 'm':
            mode = strperm(pfx = opt_info.arg, &opt_info.arg, S_IRWXU);
            if (*opt_info.arg)
                error(ERROR_exit(0), "%s: invalid mode", pfx);
            continue;
        case 'p':
            if ((t = getenv("TMPDIR")) && *t)
                dir = 0;
            else
                dir = opt_info.arg;
            continue;
        case 'q':
            quiet = 1;
            continue;
        case 't':
            dir = 0;
            continue;
        case 'u':
            unsafe = 1;
            fdp = 0;
            continue;
        case 'R':
            if (!pathtemp(NiL, 0, opt_info.arg, "/seed", NiL))
                error(2, "%s: regression test initializtion failed", opt_info.arg);
            continue;
        case ':':
            error(2, "%s", opt_info.arg);
            break;
        case '?':
            error(ERROR_usage(2), "%s", opt_info.arg);
            break;
        }
        break;
    }
    argv += opt_info.index;
    if (error_info.errors || (pfx = *argv++) && *argv)
        error(ERROR_usage(2), "%s", optusage(NiL));
    mask = umask(0);
    if (!mode)
        mode = (fdp ? (S_IRUSR|S_IWUSR) : S_IRWXU) & ~mask;
    umask(~mode & (S_IRWXU|S_IRWXG|S_IRWXO));
    if (!pfx)
    {
        pfx = "tmp_";
        if (dir && !*dir)
            dir = 0;
    }
    if (t = strrchr(pfx, '/'))
    {
        i = ++t - pfx;
        dir = fmtbuf(i);
        memcpy(dir, pfx, i);
        dir[i] = 0;
        pfx = t;
    }
    for (;;)
    {
        if (!pathtemp(path, sizeof(path), dir, pfx, fdp))
        {
            if (quiet)
                error_info.errors++;
            else
                error(ERROR_SYSTEM|2, "cannot create temporary path");
            break;
        }
        if (fdp || unsafe || !mkdir(path, mode))
        {
            if (fdp)
                close(*fdp);
            sfputr(sfstdout, path, '\n');
            break;
        }
        if (sh_checksig(context))
        {
            error_info.errors++;
            break;
        }
    }
    umask(mask);
    return error_info.errors != 0;
}