The Transpose File problem on LeetCode is a problem that requires the user to write a bash script that transposes the rows and columns of a given file. The file contains delimited fields, and the transposed file should have the delimiter replaced with a space character.

Here is a detailed solution to the Transpose File problem on LeetCode:

Solution

First, we need to create a file named "file.txt" with the input data. For example, the following is the contents of file.txt:

name,age,gender
Alice,25,Female
Bob,30,Male
Charlie,35,Male

The bash command to create file.txt is:

cat << EOT > file.txt
name,age,gender
Alice,25,Female
Bob,30,Male
Charlie,35,Male
EOT

Next, we can use the awk command to transpose the rows and columns of the file. Specifically, we will use the following command:

awk '{
    for(i=1;i<=NF;i++){
        if(NR==1){
            s[i]=$i;
        } else {
            s[i]=s[i]" "$i;
        }
    }
} END {
    for(i=1;i<=NF;i++){
        print s[i];
    }
}' file.txt

The awk command works as follows:

• For each line (row) of the input file, we loop through each field (column) by using the for loop with a counter variable i.
• If the current row is the first row (e.g., NR==1), then we initialize an array s with the current field as the value for the i-th index of the array.
• If the current row is not the first row, then we append the current field to the i-th index of the s array by concatenating a space character and the current field with the previous value of the s array for that index.
• Finally, after reading all the lines of the input file, we loop through each index of the s array and print the value of the i-th index, which now contains the transposed row.

The output of the above command should be:

name Alice Bob Charlie
age 25 30 35
gender Female Male Male

Note that the delimiter (comma) is replaced with a space character. Also note that the first row of the input file becomes the first column of the output file, and vice versa for the other rows.

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