1 #!/bin/bash

     2 

     3 # Relational pipes

     4 # Copyright © 2020 František Kučera (Frantovo.cz, GlobalCode.info)

     5 #

     6 # This program is free software: you can redistribute it and/or modify

     7 # it under the terms of the GNU General Public License as published by

     8 # the Free Software Foundation, version 3 of the License.

     9 #

    10 # This program is distributed in the hope that it will be useful,

    11 # but WITHOUT ANY WARRANTY; without even the implied warranty of

    12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

    13 # GNU General Public License for more details.

    14 #

    15 # You should have received a copy of the GNU General Public License

    16 # along with this program. If not, see <http://www.gnu.org/licenses/>.

    17 

    18 

    19 # This streamlet provides a single attribute: number of lines of given file

    20 # Standard wc -l is used to count the lines.

    21 # Directories are reported a 0 lines and with a null flag (will be supported in further Relational pipes versions).

    22 

    23 

    24 . "$(dirname $0)/streamlet-common.sh"

    25 

    26 processMessage_WAITING_FOR_OUTPUT_ATTRIBUTES_METADATA() {

    27 	send OUTPUT_ATTRIBUTE_METADATA "${outputAttributeAliases[0]-lines_count}"    "integer"

    28 	send WAITING_FOR_INPUT_ATTRIBUTES

    29 }

    30 

    31 processMessage_WAITING_FOR_OUTPUT_ATTRIBUTES() {

    32 	if [[ -d "$currentFile" ]]; then

    33 		value="0";

    34 		isNull="true";

    35 	else

    36 		value=$(wc -l "$currentFile" | cut -d" " -f1);

    37 		isNull="false";

    38 	fi

    39 	

    40 	send OUTPUT_ATTRIBUTE "$value"    "$isNull";

    41 	send WAITING_FOR_INPUT_ATTRIBUTES;

    42 }

    43 

    44 initialize

    45 processMessages