Shellcheck rewrites (#9597)

* Fix SC2001: See if you can use ${variable//search/replace} instead.

* Fix SC2010: Don't use ls | grep. Use a glob or a for loop with a condition to allow non-alphanumeric filenames.

* Fix SC2012: Use find instead of ls to better handle non-alphanumeric filenames.

* Fix SC2015: Note that A && B || C is not if-then-else. C may run when A is true.

* Fix SC2028: echo may not expand escape sequences. Use printf.

* Fix SC2034: variable appears unused. Verify use (or export if used externally).

* Fix SC2035: Use ./*glob* or -- *glob* so names with dashes won't become options.

* Fix SC2071: > is for string comparisons. Use -gt instead.

* Fix SC2154: variable is referenced but not assigned

* Fix SC2164: Use 'cd ... || exit' or 'cd ... || return' in case cd fails.

* Fix SC2188: This redirection doesn't have a command. Move to its command (or use 'true' as no-op).

* Fix SC2236: Use -n instead of ! -z.

* Fix SC2242: Can only exit with status 0-255. Other data should be written to stdout/stderr.

* Fix SC2086: Double quote to prevent globbing and word splitting.

Co-authored-by: Mehrdad <noreply@github.com>

python/build-wheel-manylinux1.sh

@@ -72,6 +72,8 @@ done
 
 # Rename the wheels so that they can be uploaded to PyPI. TODO(rkn): This is a
 # hack, we should use auditwheel instead.
-pushd .whl
-  find *.whl -exec bash -c 'mv $1 ${1//linux/manylinux1}' bash {} \;
-popd
+for path in .whl/*.whl; do
+  if [ -f "${path}" ]; then
+    mv "${path}" "${path//linux/manylinux1}"
+  fi
+done