Golang exec.Command multiple pipes

Question

I'm trying to do multiple pipes with Go:

ctags := exec.Command("ctags", "-x", "--c-types=f", "./tmp/"+fileName)
grep  := exec.Command("grep", "member")
awk   := exec.Command("awk", "'{$1=$2=$3=$4=\"\"; print $0}'")
grep.Stdin, _ = ctags.StdoutPipe()
awk.Stdin, _ = grep.StdoutPipe()
awk.Stdout = os.Stdout
_ = grep.Start()
_ = awk.Start()
_ = ctags.Run()
_ = grep.Wait()
_ = awk.Wait()

fmt.Println(awk)

This is what the expected output should look like:

$ ctags -x --c-types=f ./tmp/genetic_algorithm.py | grep member | awk '{$1=$2=$3=$4=""; print $0}'
    def __init__(self, vector, fitness_function):
    def __init__(self, population_size=10, crossover_points=[.3, .6],
    def apply_crossover(self, genotype_1, genotype_2):
    def apply_mutation(self, child_genotype):
    def calc_population_fitness(self, individuals):
    def evolve(self):
    def final_genotype(self):
    def fitness(self):
    def generate_offspring(self, selected):
    def genotype(self, indiv):
    def get_accuracy(nn_hidden_structure=[10]):
    def parse_bitstring(self, genotype):
    def run(self):
    def select_for_crossover(self):
    def slice_vector(self, vector):
    def validate_vector(self, vector, max_nodes=100):
    def vector_from_bitstring(self, genotype):

This is what I'm getting:

&{/usr/bin/awk [awk '{$1=$2=$3=$4=""; print $0}'] []  0xc4204ce020 0xc42007e008 <nil> [] <nil> 0xc4201fa900 exit status 2 <nil> <nil> true [0xc4204ce020 0xc42007e008 0xc4204ce048] [0xc4204ce048] [] [] 0xc420070360 <nil>}

I've found several examples of piping commands with Go, but most of them only pipe two commands. There's this example https://gist.github.com/dagoof/1477401, but when I arranged my code according to that logic, I got the same issue. Am I piping correctly? The command is just supposed to execute exuberant ctags on that Python file and then grep any rows indicating method and then only ignore the first four columns of the grepped output.

Answer 1

The issue was with:

awk   := exec.Command("awk", "'{$1=$2=$3=$4=\"\"; print $0}'")

I just needed to remove the single quotes.

awk   := exec.Command("awk", "{$1=$2=$3=$4=\"\"; print $0}")