How to parse and distinguish different and varying arguments of a user command with a regular expression?
I'm trying to interpret user commands as dash optional flag.
{run -o -f -a file1 file2}
Something like this:
/{run (-o|-f) (\w+) (.+?)}/g;
Is very limiting with only 1 choice of flag.
I'm looking for a regex that can properly parse the string with any amount of dash flags, spit out the flags into groups, and not worry about a set amount of whitespace in between.
string = "{run -a file1 file2}"
string = "{run -a -o -f file1 file2}"
string = "{run -f-a-o file1 file2}"
string.match(regex) should output each flag and each file name.
Example output would be:
["f", "a", "o", "file1", "file2"]
Or if not possible, something like this:?
["-f-a-o", "file1", "file2"]
Solution 1:
A single regex is capable of capturing a maximum amount of 9 groups.
Thus ... "parse[ing a] string with any amount of dash flags" ... like the OP does demand can not be achieved by a single regex alone.
A good enough approach was to capture both groups, the flags sequence and the files sequence and then to process them into a concatenated list of separated flag and file name items ...
// see ... [https://regex101.com/r/VFjeK1/1]
const regXFlagsAndFiles =
(/^\{\s*run(?:\s+-(?<flags>[a-z]+(?:\s*-[a-z]+)*))*\s+(?<files>[\w.]+(?:\s+[\w.]+)*)\s*\}$/);
function parseFlagAndFileList(value) {
const {
flags,
files,
} = regXFlagsAndFiles
.exec(String(value))
?.groups || {};
return (flags
?.split(/\s*-\s*/)
?? []
).concat(
files
?.split(/\s+/)
?? []
);
}
console.log([
'{run file1 file2}',
'{run -a file1 file2}',
'{run -a -o -f file1 file2}',
'{run -f-a-o file1 file2}',
].map(parseFlagAndFileList));
console.log([
'{run}',
'{run }',
'{run file1 }',
'{run -abc file1.foo file2.bar }',
'{run -ab -ogg -fgg file1.baz file2 }',
'{run -f-a-ob file1 file2.biz }',
'{ run -a -b }',
'{ fun -a -b }',
].map(parseFlagAndFileList));.as-console-wrapper { min-height: 100%!important; top: 0; }A regex which almost covers the OP's wish of doing it all with just one simple pattern would look like this one ... /[\w.]+/g.
It of cause ...
- covers no validation at all,
- and needs to be supported by ...
-
String.prototype.matchand -
Array.prototype.slice.
-
// see ... [https://regex101.com/r/VFjeK1/3]
const regXCommandTokens = (/[\w.]+/g);
console.log([
'{run file1 file2}',
'{run -a file1 file2}',
'{run -a -o -f file1 file2}',
'{run -f-a-o file1 file2}',
].map(command => command.match(regXCommandTokens).slice(1)));
console.log([
'{run}',
'{run }',
'{run file1 }',
'{run -abc file1.foo file2.bar }',
'{run -ab -ogg -fgg file1.baz file2 }',
'{run -f-a-ob file1 file2.biz }',
'{ run -a -b }',
'{ fun -a -b }',
].map(command => command.match(regXCommandTokens).slice(1)));.as-console-wrapper { min-height: 100%!important; top: 0; }