Use regular (not Perl) grep syntax in scripts (#887)

Mac platforms are become more locked-down and when grep is installed
by XCode for example it is a BSD version not GNU version so doesn't
have the "-P" option to use perl patterns. This fixes scripts to not
depend on GNU grep.

script/generate

@@ -117,7 +117,9 @@ trust_sdk_and_extensions()
 
         # Parse extension name
         local extension_name=""
-        extension_name=$(grep -oP '^id: \K(.*)' "${slce_file}")
+        extension_line=$(grep -m 1 'id: ' "${slce_file}")
+        extension_name="${extension_line//id:/}"
+        extension_name="${extension_name// /}"
 
         # Define symlink location
         local extension_symlink="${sdk_dir}/extension/${extension_name}"
@@ -174,7 +176,9 @@ generate()
     # Define generation variables
     local slcp=${1?A .slcp file is expected as the first argument}
     local project_name=""
-    project_name=$(grep -oP 'project_name: \K(.*)' "${slcp}")
+    project_line=$(grep 'project_name: ' "${slcp}")
+    project_name="${project_line//project_name:/}"
+    project_name="${project_name// /}"
     local generation_dir=${2?A generation output dir is expected as the second argument}
     local export_templates="${repo_dir}/slc/exporter_templates/platform_library"
     local board=${3?A board is expected as the third argument}

script/util

@@ -85,10 +85,20 @@ parse_configuration()
     old_setting=${-//[^e]/}
     set +e
     # grep raw values from the configuration file
-    rcp_uart_slcp="$(grep -oP 'rcp_uart_slcp: \K(.*)' "${config_yml}")"
-    rcp_spi_slcp="$(grep -oP 'rcp_spi_slcp: \K(.*)' "${config_yml}")"
-    soc_slcp="$(grep -oP 'soc_slcp: \K(.*)' "${config_yml}")"
-    board="$(grep -oP 'board: \K(.*)' "${config_yml}")"
+    line="$(grep 'rcp_uart_slcp:' "${config_yml}")"
+    rcp_uart_slcp="${line//rcp_uart_slcp:/}"
+    line="$(grep 'rcp_spi_slcp:' "${config_yml}")"
+    rcp_spi_slcp="${line//rcp_spi_slcp:/}"
+    line="$(grep 'soc_slcp:' "${config_yml}")"
+    soc_slcp="${line//soc_slcp:/}"
+    line="$(grep 'board:' "${config_yml}")"
+    board="${line//board:/}"
+
+    # Strip spaces
+    rcp_uart_slcp="${rcp_uart_slcp// /}"
+    rcp_spi_slcp="${rcp_spi_slcp// /}"
+    soc_slcp="${soc_slcp// /}"
+    board="${board// /}"
 
     # Strip quotes
     rcp_uart_slcp=$(eval echo "${rcp_uart_slcp}")