| 1 | /* |
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| 2 | * Copyright (c) 1987 Regents of the University of California. |
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| 3 | * All rights reserved. |
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| 4 | * |
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| 5 | * Redistribution and use in source and binary forms are permitted |
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| 6 | * provided that the above copyright notice and this paragraph are |
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| 7 | * duplicated in all such forms and that any documentation, |
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| 8 | * advertising materials, and other materials related to such |
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| 9 | * distribution and use acknowledge that the software was developed |
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| 10 | * by the University of California, Berkeley. The name of the |
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| 11 | * University may not be used to endorse or promote products derived |
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| 12 | * from this software without specific prior written permission. |
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| 13 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
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| 14 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
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| 15 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
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| 16 | */ |
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| 17 | |
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| 18 | #if defined(LIBC_SCCS) && !defined(lint) |
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| 19 | static char sccsid[] = "@(#)mktemp.c 5.7 (Berkeley) 6/27/88"; |
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| 20 | #endif /* LIBC_SCCS and not lint */ |
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| 21 | |
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| 22 | #include <sys/types.h> |
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| 23 | #include <sys/file.h> |
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| 24 | #include <sys/stat.h> |
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| 25 | #include <errno.h> |
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| 26 | #include <stdio.h> |
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| 27 | #include <ctype.h> |
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| 28 | |
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| 29 | #define YES 1 |
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| 30 | #define NO 0 |
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| 31 | |
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| 32 | mkstemp(as) |
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| 33 | char *as; |
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| 34 | { |
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| 35 | int fd; |
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| 36 | |
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| 37 | return (_gettemp(as, &fd) ? fd : -1); |
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| 38 | } |
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| 39 | |
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| 40 | char * |
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| 41 | mktemp(as) |
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| 42 | char *as; |
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| 43 | { |
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| 44 | return(_gettemp(as, (int *)NULL) ? as : (char *)NULL); |
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| 45 | } |
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| 46 | |
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| 47 | static |
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| 48 | _gettemp(as, doopen) |
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| 49 | char *as; |
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| 50 | register int *doopen; |
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| 51 | { |
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| 52 | extern int errno; |
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| 53 | register char *start, *trv; |
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| 54 | struct stat sbuf; |
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| 55 | u_int pid; |
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| 56 | |
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| 57 | pid = getpid(); |
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| 58 | |
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| 59 | /* extra X's get set to 0's */ |
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| 60 | for (trv = as; *trv; ++trv); |
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| 61 | while (*--trv == 'X') { |
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| 62 | *trv = (pid % 10) + '0'; |
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| 63 | pid /= 10; |
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| 64 | } |
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| 65 | |
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| 66 | /* |
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| 67 | * check for write permission on target directory; if you have |
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| 68 | * six X's and you can't write the directory, this will run for |
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| 69 | * a *very* long time. |
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| 70 | */ |
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| 71 | for (start = ++trv; trv > as && *trv != '/'; --trv); |
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| 72 | if (*trv == '/') { |
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| 73 | *trv = '\0'; |
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| 74 | if (stat(as, &sbuf) || !(sbuf.st_mode & S_IFDIR)) |
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| 75 | return(NO); |
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| 76 | *trv = '/'; |
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| 77 | } |
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| 78 | else if (stat(".", &sbuf) == -1) |
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| 79 | return(NO); |
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| 80 | |
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| 81 | for (;;) { |
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| 82 | if (doopen) { |
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| 83 | if ((*doopen = open(as, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0) |
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| 84 | return(YES); |
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| 85 | if (errno != EEXIST) |
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| 86 | return(NO); |
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| 87 | } |
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| 88 | else if (stat(as, &sbuf)) |
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| 89 | return(errno == ENOENT ? YES : NO); |
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| 90 | |
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| 91 | /* tricky little algorithm for backward compatibility */ |
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| 92 | for (trv = start;;) { |
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| 93 | if (!*trv) |
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| 94 | return(NO); |
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| 95 | if (*trv == 'z') |
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| 96 | *trv++ = 'a'; |
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| 97 | else { |
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| 98 | if (isdigit(*trv)) |
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| 99 | *trv = 'a'; |
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| 100 | else |
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| 101 | ++*trv; |
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| 102 | break; |
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| 103 | } |
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| 104 | } |
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| 105 | } |
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| 106 | /*NOTREACHED*/ |
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| 107 | } |
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