Allow comments in .terraform-version file

Using syntax:

    # this whole line is a comment
    1.2.3
    # this is also a comment

but not inline comments.

Closes tfutils#283

Author: OJFord

lib/tfenv-version-name.sh

@@ -10,7 +10,7 @@ function tfenv-version-name() {
       && log 'debug' "TFENV_VERSION_FILE retrieved from tfenv-version-file: ${TFENV_VERSION_FILE}" \
       || log 'error' 'Failed to retrieve TFENV_VERSION_FILE from tfenv-version-file';
 
-    TFENV_VERSION="$(cat "${TFENV_VERSION_FILE}" || true)" \
+    TFENV_VERSION="$(grep --invert-match '^#' "${TFENV_VERSION_FILE}" || true)" \
       && log 'debug' "TFENV_VERSION specified in TFENV_VERSION_FILE: ${TFENV_VERSION}";
 
     TFENV_VERSION_SOURCE="${TFENV_VERSION_FILE}";

libexec/tfenv-resolve-version

@@ -77,12 +77,12 @@ if [ -z "${arg}" -a -z "${TFENV_TERRAFORM_VERSION:-""}" ]; then
 
   if [ "${version_file}" != "${TFENV_CONFIG_DIR}/version" ]; then
     log 'debug' "Version File (${version_file}) is not the default \${TFENV_CONFIG_DIR}/version (${TFENV_CONFIG_DIR}/version)";
-    version_requested="$(cat "${version_file}")" \
+    version_requested="$(grep --invert-match '^#' "${version_file}")" \
       || log 'error' "Failed to open ${version_file}";
 
   elif [ -f "${version_file}" ]; then
     log 'debug' "Version File is the default \${TFENV_CONFIG_DIR}/version (${TFENV_CONFIG_DIR}/version)";
-    version_requested="$(cat "${version_file}")" \
+    version_requested="$(grep --invert-match '^#' "${version_file}")" \
       || log 'error' "Failed to open ${version_file}";
 
     # Absolute fallback

libexec/tfenv-uninstall

@@ -69,11 +69,11 @@ if [ -z "${arg:-""}" -a -z "${TFENV_TERRAFORM_VERSION:-""}" ]; then
   log 'debug' "Version File: ${version_file}";
   if [ "${version_file}" != "${TFENV_CONFIG_DIR}/version" ]; then
     log 'debug' "Version File (${version_file}) is not the default \${TFENV_CONFIG_DIR}/version (${TFENV_CONFIG_DIR}/version)";
-    version_requested="$(cat "${version_file}")" \
+    version_requested="$(grep --invert-match '^#' "${version_file}")" \
       || log 'error' "Failed to open ${version_file}";
   elif [ -f "${version_file}" ]; then
     log 'debug' "Version File is the default \${TFENV_CONFIG_DIR}/version (${TFENV_CONFIG_DIR}/version)";
-    version_requested="$(cat "${version_file}")" \
+    version_requested="$(grep --invert-match '^#' "${version_file}")" \
       || log 'error' "Failed to open ${version_file}";
   else
     log 'debug' "Version File is the default \${TFENV_CONFIG_DIR}/version (${TFENV_CONFIG_DIR}/version) but it doesn't exist";

libexec/tfenv-use

@@ -76,7 +76,7 @@ if [ -z "${requested_arg}" -a -z "${TFENV_TERRAFORM_VERSION:-""}" ]; then
   version_source_suffix=" (set by ${loaded_version_file})";
 
   if [ -f "${loaded_version_file}" ]; then
-    requested="$(cat "${loaded_version_file}" || true)";
+    requested="$(grep --invert-match '^#' "${loaded_version_file}" || true)";
   else
     # No-one asked for anything, no default version is set either
     requested='latest';