today i'm trying to parse a 'ps aux' output (issued from a node.js server)
so i made an happy regex to parse the values, and i wanted to put all those fancy informations into a simple JSON object :-)
problem is, the regex i've made has 3 match groups, doing multiple matches... and i don't even know if it's possible to have it all the matches returned.
var spawn = require("child_process").spawn;
function exec(http_req, http_resp){
var re_ps = /(?:([\d\.\w\-\?\/\+]+)\s+){8}(?:((?:\d+\:\d+)|(?:\w+\d+))\s+){2}([^\n]+)/g,
result_re_ps,
array_re_ps = [];
//[USER, PID, %CPU, %MEM, VSZ, RSS, TTY, STAT], dates[START, TIME], COMMAND
var ps_process = spawn("ps", ["aux"]);
ps_process.stdout.on("data", function(data){
var split_data = data.toString().split('\n');
for (var i=1; i < 2; i++){
while ((result_re_ps = re_ps.exec(split_data[i])) != null){
console.log("--- while iteration ---");
console.dir(result_re_ps);
//console.dir(result_re_ps);
}
}
//http_resp.write(data);
});
ps_process.on("exit", function (code) {
if (code !== 0) {
console.log("ps_process exited with code " + code);
}
http_resp.end();
});
}
exports.exec = exec;
the "--- while iteration ---" it's just one per each line, instead, it should be multiples!
I will link a fancy screenshot to let you visually understand what kind of data i'm expecting
As you can see the above are 3 groups of data, each one with multiple occurrences
Any help? :p
EDITED TO CLARIFY:
This is the result of a line like:
root 5213 0.0 2.1 8688 2760 ? Ss 11:33 0:01 sshd: root@pts/0
As you can see, the resulting array is 1-dimensional, instead for the results to be contained entirely it HAS to be at least 2-dimensional
UPDATE:
For now i've solved the problem changin my code like this:
var spawn = require("child_process").spawn;
function exec(http_req, http_resp){
var array_re_ps = [];
var re_ps1 = /(?:([\d\.\w\-\?\/\+]+)\s+)/g,
re_ps2 = /(?:((?:\d+\:\d+)|(?:\w+\d+))\s+)/g,
re_ps3 = /([^\n]+)/g;
//[USER, PID, %CPU, %MEM, VSZ, RSS, TTY, STAT], dates[START, TIME], COMMAND
var ps_process = spawn("ps", ["aux"]);
ps_process.stdout.on("data", function(data){
var split_data = data.toString().split('\n');
for (var i=20; i < 21; i++){
array_re_ps[0] = [], array_re_ps[1] = [];
for (var j=0; j<8; j++){
array_re_ps[0].push(re_ps1.exec(split_data[i])[1]);
}
re_ps2.lastIndex = re_ps1.lastIndex;
for (var j=0; j<2; j++){
array_re_ps[1].push(re_ps2.exec(split_data[i])[1])
}
re_ps3.lastIndex = re_ps2.lastIndex;
array_re_ps[2] = re_ps3.exec(split_data[i])[1];
console.dir(array_re_ps);
}
});
ps_process.on("exit", function (code) {
if (code !== 0) {
console.log("ps_process exited with code " + code);
}
http_resp.end();
});
}
exports.exec = exec;
Basically i split my long regexp, in 3 smaller ones, and i do cycle through their results. If you try the code i formatted the resulting array exactly as i wanted, but i still think that it's a side-solution.
Since Regular Expressions lets you "multiple parse group multiple times", it is possible to have that functionality in javascript?
Take a look at the return values of the exec
function.
It returns the index where it first matched, the original string and the capture groups in the elements [0]...[n]
.
All this is available in your output, you just have to iterate through the single elements of the array.