Stripping off extra spaces from a string

Question

You are given a string. Output the string with one space per words.

Challenge

Input will be a string (not null or empty), surrounded with quotes(") sent via the stdin. Remove leading and trailing spaces from it. Also, if there are more than one space between two words (or symbols or whatever), trim it to just one space. Output the modified string with the quotes.

Rules

• The string will not be longer than 100 characters and will only contain ASCII characters in range (space) to ~(tilde) (character codes 0x20 to 0x7E, inclusive) except ",i.e, the string will not contain quotes(") and other characters outside the range specified above. See ASCII table for reference.
• You must take input from the stdin( or closest alternative ).
• The output must contain quotes(").
• You can write a full program, or a function which takes input (from stdin), and outputs the final string

Test Cases

"this  is  a    string   "         --> "this is a string"

"  blah blah    blah "             --> "blah blah blah"

"abcdefg"                          --> "abcdefg"

"           "                      --> ""

"12 34  ~5 6   (7, 8) - 9 -  "     --> "12 34 ~5 6 (7, 8) - 9 -" 

Scoring

This is code golf, so the shortest submission (in bytes) wins.

Answer 1

Objective-C 215

-(NSString*)q:(NSString*)s{NSArray*a=[s componentsSeparatedByString:@" "];NSMutableString*m=[NSMutableString new];for(NSString*w in a){if(w.length){[m appendFormat:@"%@ ",w];}}return[m substringToIndex:m.length-1];}

Uncompressed version:

-(NSString*)q:(NSString*)s{
    NSArray *a=[s componentsSeparatedByString:@" "];
    NSMutableString *m=[NSMutableString new];
    for (NSString *w in a) {
        if (w.length) {
            [m appendFormat:@"%@ ",w];
        }
    }
    return[m substringToIndex:m.length-1];
}

Answer 2

Bash ,14 bytes

read f;echo $f       # assume f="this  is  a    string   "

Answer 3

Python2, 28 Bytes

lambda s:" ".join(s.split())

---

Explanation

lambda s

Anonymous function which takes as input s.

s.split()

Returns a list of the words (which are separated by arbitrary strings of whitespace characters) of the string s.

" ".join(...)

Joins list back into a string, with each word separated by a space (" ").

Answer 4

k4, 23 bytes

" "/:x@&~~#:'x:" "\:0:0

---

                    0:0  / read from stdin
             x:" "\:     / split string on spaces and assign to x
        ~~#:'            / boolean true where string len>0, bool false otherwise
     x@&                 / x at indices where true
" "/:                    / join with spaces

Answer 5

Wren, 56 bytes

Wait. The replace only does it once? Now I have to use the split-join combo.

Fn.new{|x|x.trim().split(" ").where{|i|i!=""}.join(" ")}

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Explanation

Fn.new{|x|                                             } // New anonymous function with the operand x
          x.trim()                                       // Trim out whitespace from both sides of the string
                  .split(" ")                            // Split the string into space-separated chunks
                             .where{|i|i!=""}            // Keep all of those that aren't the null string (due to two consecutive spaces)
                                             .join(" ")  // Join the replaced list together

Answer 6

Husk, 5 bytes

sJ' w

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Fully ascii!

Explanation

sJ' w
    w split into words
 J'   join with spaces
s     add quotes

Answer 7

Python 3, 37 bytes

print("%r"%' '.join(input().split()))

Based of user12205's python2 answer. I've replaced the %s with a %r so that single quotes are printed around the string automatically.

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Answer 8

Factor, 23 bytes

[ [ 32 = ] " "compact ]

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Factor has a combinator called compact that does this. From the documentation:

Generate a new sequence where all runs of elements for which the predicate returns true are replaced by a single instance of elt. Runs at the beginning or end of the sequence for which the predicate returns true are removed.

Answer 9

Alice, 31 bytes

/ot!h';$ !Q'w!/
@Mq!"~K'.% >]]\

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Mt!h~;' %Qw]!]' !.$K'"!qo@  Flattened, without flow characters
M                           Read an argument, push it on the stack
 t!h~;                      Remove the leading and trailing quote, write one of them on the tape
      '                     Adds a space on the stack
        %                   Pop the space, pop the argument, split the argument by space and push all of them words on the stack
         Q                  Reverse the stack
          w      .$K        While the stack is not empty
           ]                Go to the end of the tape
            !]              Pop a word from the stack, write to the tape, go to the end of the tape
              ' !           Add a space on the stack
                    '"!     Write a quote on the tape, overwriting the last space
                       q    Concatenate the content of the tape, word and spaces, push the result on the stack
                        o   Pop, output the concatenated result
                         @  Bye