I have a bash script which is called from a nodejs http-server upon a GET request from a web-browser. The output from the bash script is returned to the browser via the http-server.
The purpose of the bash script, is to search a file for the search words supplied by the web-browser and return the search result to the http-server, which in turn send the result to the web-browser.
The bash script receive the following arguments:
CS/NCS --> Case-sensitive search or not.
OR/AND --> 'AND' or 'OR' search.
one or more searchwords
E.g.
'search_index.sh CS AND searchword1 searchword2'
'search_index.sh NCS OR searchword1 searchword2 searchword3'
Egrep is used to search for words in the file.
In line 26/29 an 'OR' search is performed. Egrep is called with the 'OR' search string. This works perfectly. The search result is shown in the web-browser.
For doing an 'AND' search I'm building an egrep search string from line 33 and forward. In line 50 the egrep search string is executed by the eval command.
If I run the script manually it is working fine. I can see the search result written to the console.
When run by the http-server (web-browser), I do not see anything returned to the web-browser
Is there another way to execute the egrep search string (line 50), that won't breake the return of the search result to the http-server?
1 #!/bin/bash
3 # search_index.sh v0.1 (p) april 2021
4 PARAMS=("$@")
5 T=1
6 declare -a SEARCH
7 for WORD in "${PARAMS[@]}"
8 do
9 if [[ $T -eq 1 ]]; then
10 CS_TYPE=$WORD
11 ((T=T+1))
12 continue
13 fi
14 if [[ $T -eq 2 ]]; then
15 LOG_TYPE=$WORD
16 ((T=T+1))
17 continue
18 fi
19 SEARCH+=("$WORD ")
20 done
21 INDEXFILE="/home/user/search/file.idx"
22 if [[ "$LOG_TYPE" = "OR" ]]; then
23 printf -v SEARCH_STR "%s" "${SEARCH[@]}"
24 SEARCH_STR=$( echo $SEARCH_STR | tr ' ' '|' )
25 if [[ "$CS_TYPE" = "NCS" ]]; then
26 egrep --ignore-case $SEARCH_STR $INDEXFILE
27 exit
28 else
29 egrep $SEARCH_STR $INDEXFILE
30 exit
31 fi
32 else
33 if [[ "$CS_TYPE" = "NCS" ]]; then
34 GREP_VAR="egrep --ignore-case "
35 else
36 GREP_VAR="egrep "
37 fi
38 I=0
39 for POS in "${SEARCH[@]}"
40 do
41 if [[ $I -eq 0 ]]; then
42 GREP_STRING="$GREP_VAR ${SEARCH[$I]} $INDEXFILE "
43 ((I=I+1))
44 continue
45 else
46 GREP_STRING+="| $GREP_VAR ${SEARCH[$I]} "
47 ((I=I+1))
48 fi
49 done
50 eval $GREP_STRING
51 fi
1 // server.js
2 // HTTP-server for the bash search script ('search_index.sh').
3 // Example call: http://192.168.88.10:8888?SEARCH=NCS AND search_word1 search_word2
4 const { createServer } = require("http");
5 const { parse } = require("url");
6 const spawn = require('child_process').spawn;
7 function onRequest(request, response) {
8 var params = parse(request.url,true).query;
9 const proc = spawn('search_index.sh', [params.SEARCH]);
10 let output = '';
11 proc.stdout.on('data', (chunk) => {
12 output += chunk.toString();
13 });
14 proc.on('exit', () => {
15 response.writeHeader(200, {'Content-Type': 'text/plain'});
16 response.end(output);
17 console.log(output);
18 });
19 };
20 createServer(onRequest).listen(8888);
UPDATE: The server code below using execSync is working. Thanks to Taylor G. for the hint.
1 const { createServer } = require("http"); // http.createServe
2 const { parse } = require("url"); // url.parse
3 const { execSync } = require('child_process');
4 function onRequest(request, response) {
5 let result = execSync('search_index.sh').toString();
6 response.writeHeader(200, {'Content-Type': 'text/plain'});
7 response.end(result);
8 };
9 createServer(onRequest).listen(8118);
