Read a File and Split Each Line into Multiple Variables

read a file and split each line into multiple variables

read can do this itself. See BashFAQ #1.

while IFS=$'\t' read -r key value; do
  echo "First Var is $key - Remaining Line Contents Are $value"
done

Note that if you want to discard any content after the second column (rather than appending that content to the value), this would instead be:

while IFS=$'\t' read -r key value _; do
  echo "First Var is $key - Second Var is $value"
done

If you want to store the IDs in such a way as to be able to look them up by name, an associative array (added in bash 4.0) is the right tool:

declare -A color_ids=( )
while IFS=$'\t' read -r key value; do
  color_ids[$key]=$value
done

for name in "${!color_ids[@]}"; do
  value=${color_ids[$name]}
  echo "Stored name $name with value $value"
done

How to split up a line in a text file into multiple variables in C

You can sscanf() to split the line.

Since I was bored, I did this:

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct
{
  char* model;
  float version;
  int   price;
  char* color;
}
vehicle;

bool vehicle_create( vehicle* v, const char* model, float version, int price, const char* color )
{
  v->model   = strdup( model );
  if (!(v->model)) return false;

  v->version = version;
  v->price   = price;
  v->color   = strdup( color );  

  if (v->color) return true;

  free( v->model );
  return false;
}

void vehicle_destroy( vehicle* v )
{
  if (!v) return;
  if (v->model) free( v->model ); v->model = NULL;
  if (v->color) free( v->color ); v->color = NULL;
}

bool read_vehicle( FILE* f, vehicle* v )
{
  char  model[ 50 ];
  char  color[ 50 ];
  char  line[ 200 ];
  float version;
  int   price;

  if (!fgets( line, sizeof(line), f )) 
    return false;

  if (4 != sscanf( line, "%50s %f %d %50s", model, &version, &price, color ))
    return false;

  return vehicle_create( v, model, version, price, color );
}

size_t read_vehicle_inventory( FILE* f, vehicle* vs, size_t n )
{
  size_t count = 0;
  while (count < n 
      && read_vehicle( f, vs + count ))
    count += 1;
  return count;
}

int main()
{
  const size_t MAX_INVENTORY_SIZE = 100;
  vehicle inventory[ MAX_INVENTORY_SIZE ];
  size_t inventory_size = 0;

  // Load inventory from file
  inventory_size = read_vehicle_inventory( stdin, inventory, MAX_INVENTORY_SIZE );

  printf( "inventory size = %d\n", (int)inventory_size );

  // Display the inventory
  for (size_t n = 0; n < inventory_size; n++)
    printf( "%s %s %f is $%d\n", 
      inventory[ n ].color,
      inventory[ n ].model,
      inventory[ n ].version,
      inventory[ n ].price );

  // Free inventory
  for (size_t n = 0; n < inventory_size; n++)
    vehicle_destroy( inventory + n );

  return 0;
}

Enjoy.

Read file and split each line into multiple variable in C++

What is the best way to split each line?

I would simply call while(std::getline(stream, line) to read each line, then for each read line, I would put it into a istringstream (iss), and call while(std::getline(iss, value, '#')) repeatedly (with stream being your initial stream, and line and value being strings). The first value read in the inner loop will be the key; the rest, will be the values.

Some code:

auto read_file(std::istream& in)
{
    using namespace std;
    map<string, vector<string>> values;
    string line;
    while(getline(in, line))
    {
        istringstream linein{ line };
        string key, value;
        if(!getline(linein, key, '#'))
            throw runtime_error{ "bad file format" };
        while(getline(linein, value, '#') && !value.empty())
            values[key].emplace_back(move(value));
    }
    return values;
}

std::ifstream in{ "file-of-this-type.txt" };
auto values = read_file(in);

How to split a line of a txt file into different variables?

You should use split() :

String names[] = new String[10];
int numbr[] = new int[10];
    for(int i = 0; i<names.length;  i++){
        String line = reader.readLine();
        if(line != null){
            names[i] = line.split(" ")[0];
            numbr[i] = Integer.parseInt(line.split(" ")[1]);

        }

    }      

Ref : http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#split(java.lang.String)

Python3, read line by line from txt file and split line into two variables

Use readlines to read the text then iterate through the text

with open(filepath, 'r') as fp:
    lines = fp.readlines()
for x in lines:
    sp = x.split(":")
    firstname, lastname = sp[0], sp[1]
    print(firstname,lastname)

Read a file and split each line into two variables with bash program

Here is how you would debug your program:

#!/bin/bash

while read ligne
do
var1=$(echo $ligne | cut -f1 -d' ')
var2=$(echo $ligne | cut -f2 -d' ')

if [[ "$var1" != "" && "$var2" != "" ]]; then
    echo "$var1" '|' "$var2"
    #java -Xmx1024m -cp lib/*:esalib.jar clldsystem.esa.ESAAnalyzer "$var1" "$var2"
else
    echo "Vars Not Found"
    #java -Xmx1024m -cp lib/*:esalib.jar clldsystem.esa.ESAAnalyzer
fi
done < mm.txt

Running this gives the following output:

vehicle car | vehicle car
computer program | computer program
volley ball | volley ball

This means that your cut command is not correct. You have a few options to fix it:

1. Use multi-variable read as user3035772 pointed out. This is less flexible because it relies on the separator being $IFS, which you are implicitly not agreeing to.
2. Fix the delimiter in mm.txt to be - as the -d- flag of the cut command requires:
   
vehicle-car
computer-program
volley-ball

3. Fix the cut command to require a space delimiter as you have in mm.txt: cut -f1 -d' '.

How to read variables from file, with multiple variables per line?

I think all you're looking for is to read multiple variables per line: the read command can assign words to variables by itself.

while read -r first second third; do
    do_stuff_with "$first"
    do_stuff_with "$second"
    do_stuff_with "$third"
done < ./test.txt

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