Function cbm_copy_binary_to_target

src/cli/cli.c:384–395

Copy the running binary into the canonical install target, preserving the * executable bit. When src and dst are the same on-disk file the copy is * skipped: cbm_copy_file opens dst "wb" before reading src, so copying a file * onto itself would truncate it to zero. Returns 0 on success or skip, * CLI_ERR on failure. Exposed (non-static) as the regression surface for the * `install --force` bi

 * CLI_ERR on failure. Exposed (non-static) as the regression surface for the
 * `install --force` binary-swap bug (#472). */
int cbm_copy_binary_to_target(const char *src, const char *dst) {
    if (cbm_same_file(src, dst)) {
        return 0; /* already in place — nothing to copy */
    }
    if (cbm_copy_file(src, dst) != 0) {
        return CLI_ERR;
    }
#ifndef _WIN32
    (void)chmod(dst, CLI_OCTAL_PERM);
#endif
    return 0;
}

/* Replace a binary file. Unlinks the old file first (handles read-only and
 * running binaries on Unix where unlink succeeds on open files). On all