mirror of
https://github.com/fluencelabs/musl
synced 2025-06-05 11:01:37 +00:00
400c5e5c83
to deal with the fact that the public headers may be used with pre-c99 compilers, __restrict is used in place of restrict, and defined appropriately for any supported compiler. we also avoid the form [restrict] since older versions of gcc rejected it due to a bug in the original c99 standard, and instead use the form *restrict.
50 lines
892 B
C
50 lines
892 B
C
#include <stdlib.h>
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#include <stdio.h>
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#include <limits.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <unistd.h>
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char *realpath(const char *restrict filename, char *restrict resolved)
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{
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int fd;
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ssize_t r;
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struct stat st1, st2;
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char buf[15+3*sizeof(int)];
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int alloc = 0;
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if (!filename) {
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errno = EINVAL;
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return 0;
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}
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fd = open(filename, O_RDONLY|O_NONBLOCK);
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if (fd < 0) return 0;
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snprintf(buf, sizeof buf, "/proc/self/fd/%d", fd);
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if (!resolved) {
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alloc = 1;
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resolved = malloc(PATH_MAX);
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if (!resolved) return 0;
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}
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r = readlink(buf, resolved, PATH_MAX-1);
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if (r < 0) goto err;
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resolved[r] = 0;
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fstat(fd, &st1);
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r = stat(resolved, &st2);
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if (r<0 || st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino) {
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if (!r) errno = ELOOP;
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goto err;
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}
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close(fd);
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return resolved;
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err:
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if (alloc) free(resolved);
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close(fd);
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return 0;
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}
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