busybox/libbb/mode_string.c

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/* vi: set sw=4 ts=4: */
/*
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* mode_string implementation for busybox
*
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* Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
/* Aug 13, 2003
* Fix a bug reported by junkio@cox.net involving the mode_chars index.
*/
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#include <assert.h>
#include <sys/stat.h>
#include "libbb.h"
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#if ( S_ISUID != 04000 ) || ( S_ISGID != 02000 ) || ( S_ISVTX != 01000 ) \
|| ( S_IRUSR != 00400 ) || ( S_IWUSR != 00200 ) || ( S_IXUSR != 00100 ) \
|| ( S_IRGRP != 00040 ) || ( S_IWGRP != 00020 ) || ( S_IXGRP != 00010 ) \
|| ( S_IROTH != 00004 ) || ( S_IWOTH != 00002 ) || ( S_IXOTH != 00001 )
#error permission bitflag value assumption(s) violated!
#endif
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#if ( S_IFSOCK!= 0140000 ) || ( S_IFLNK != 0120000 ) \
|| ( S_IFREG != 0100000 ) || ( S_IFBLK != 0060000 ) \
|| ( S_IFDIR != 0040000 ) || ( S_IFCHR != 0020000 ) \
|| ( S_IFIFO != 0010000 )
#warning mode type bitflag value assumption(s) violated! falling back to larger version
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#if (S_IRWXU | S_IRWXG | S_IRWXO | S_ISUID | S_ISGID | S_ISVTX) == 07777
#undef mode_t
#define mode_t unsigned short
#endif
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static const mode_t mode_flags[] = {
S_IRUSR, S_IWUSR, S_IXUSR, S_ISUID,
S_IRGRP, S_IWGRP, S_IXGRP, S_ISGID,
S_IROTH, S_IWOTH, S_IXOTH, S_ISVTX
};
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/* The static const char arrays below are duplicated for the two cases
* because moving them ahead of the mode_flags declaration cause a text
* size increase with the gcc version I'm using. */
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/* The previous version used "0pcCd?bB-?l?s???". However, the '0', 'C',
* and 'B' types don't appear to be available on linux. So I removed them. */
static const char type_chars[16] ALIGN1 = "?pc?d?b?-?l?s???";
/***************************************** 0123456789abcdef */
static const char mode_chars[7] ALIGN1 = "rwxSTst";
const char* FAST_FUNC bb_mode_string(mode_t mode)
{
static char buf[12];
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char *p = buf;
int i, j, k;
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*p = type_chars[ (mode >> 12) & 0xf ];
i = 0;
do {
j = k = 0;
do {
*++p = '-';
if (mode & mode_flags[i+j]) {
*p = mode_chars[j];
k = j;
}
} while (++j < 3);
if (mode & mode_flags[i+j]) {
*p = mode_chars[3 + (k & 2) + ((i&8) >> 3)];
}
i += 4;
} while (i < 12);
/* Note: We don't bother with nul termination because bss initialization
* should have taken care of that for us. If the user scribbled in buf
* memory, they deserve whatever happens. But we'll at least assert. */
assert(buf[10] == 0);
return buf;
}
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#else
/* The previous version used "0pcCd?bB-?l?s???". However, the '0', 'C',
* and 'B' types don't appear to be available on linux. So I removed them. */
static const char type_chars[16] = "?pc?d?b?-?l?s???";
/********************************** 0123456789abcdef */
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static const char mode_chars[7] = "rwxSTst";
const char* FAST_FUNC bb_mode_string(mode_t mode)
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{
static char buf[12];
char *p = buf;
int i, j, k, m;
*p = type_chars[ (mode >> 12) & 0xf ];
i = 0;
m = 0400;
do {
j = k = 0;
do {
*++p = '-';
if (mode & m) {
*p = mode_chars[j];
k = j;
}
m >>= 1;
} while (++j < 3);
++i;
if (mode & (010000 >> i)) {
*p = mode_chars[3 + (k & 2) + (i == 3)];
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}
} while (i < 3);
/* Note: We don't bother with nul termination because bss initialization
* should have taken care of that for us. If the user scribbled in buf
* memory, they deserve whatever happens. But we'll at least assert. */
assert(buf[10] == 0);
return buf;
}
#endif