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This code example is noncompliant because any existing destination file is removed by rename().
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const char *src_file = /* ... */;
const char *dest_file = /* ... */;
if (rename(src_file, dest_file) != 0) {
/* Handle Error */
}
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If the programmer's intent is to not remove an existing destination file, the POSIX {{access()}} function can be used to check for the existence of a file \[[Open Group 2004|AA. Bibliography#Open Group 04]\]. This compliant solution renames the source file only if the destination file does not exist. |
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const char *src_file = /* ... */;
const char *dest_file = /* ... */;
if (access(dest_file, F_OK) != 0) {
if (rename(src_file, dest_file) != 0) {
/* Handle error condition */
}
}
else {
/* Handle file-exists condition */
}
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Consequently, it is unnecessary to explicitly check for the existence of the destination file before calling rename().
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const char *src_file = /* ... */;
const char *dest_file = /* ... */;
if (rename(src_file, dest_file) != 0) {
/* Handle Error */
}
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If the intent of the programmer is to remove the file referenced by dest_file if it exists prior to calling rename(), this code example is noncompliant on Windows platforms because rename() will fail.
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const char *src_file = /* ... */;
const char *dest_file = /* ... */;
if (rename(src_file, dest_file) != 0) {
/* Handle error */
}
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On Windows systems, it is necessary to explicitly remove the destination file before calling rename(), if you want the file to be overwritten and the rename() operation to succeed.
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const char *src_file = /* ... */;
const char *dest_file = /* ... */;
if (_access_s(dest_file, 0) == 0) {
if (remove(dest_file) != 0) {
/* Handle error condition */
}
}
if (rename(src_file, dest_file) != 0) {
/* Handle error condition */
}
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On POSIX systems, if the destination file exists prior to calling rename(), the file is automatically removed.
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const char *src_file = /* ... */;
const char *dest_file = /* ... */;
if (rename(src_file, dest_file) != 0) {
/* Handle error condition */
}
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This compliant solution ensures that any destination file is portably removed.
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const char *src_file = /* ... */;
const char *dest_file = /* ... */;
(void)remove(dest_file);
if (rename(src_file, dest_file) != 0) {
/* Handle error condition */
}
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This compliant solution renames the source file only if the destination file does not exist.
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|---|
|
const char *src_file = /* ... */;
const char *dest_file = /* ... */;
if (!file_exists(dest_file)) {
if (rename(src_file, dest_file) != 0) {
/* Handle error condition */
}
}
else {
/* Handle file-exists condition */
}
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