You should provide a compiling code. I'll assume that n and m are int, but you should have added their declaration.

• You should use explicit names for variables. n is a line count, so call it line_count. m is column_count.

• You should check the return values of scanf to be sure you handle gracefully EOF and bad input.

• You print "Error, number of colums/ligns < 1. \n" so the user doesn't know if it's the lines or the columns or both that are < 1.

• The english word is "lines", not "ligns".

• Your checks are too complicated and redundants. The entire if/else block can be replaced by this:

    while(*line_count < 1)
    {
        printf("Error, number of lines < 1. \n");
        scanf("%d", line_count);
    }
  
  
    while(*column_count < 1)
    {
        printf("Error, number of colums < 1. \n");
        scanf("%d", column_count);
    }
  
    printf("Number of lines : %x, Number of columns : %x \n", *line_count, *column_count);
  

You should provide a compiling code. I'll assume that n and m are int, but you should have added their declaration.

• You should use explicit names for variables. n is a line count, so call it line_count. m is column_count.

• You should check the return values of scanf to be sure you handle gracefully EOF and bad input.

• You print "Error, number of colums/ligns < 1. \n" every time, so the user can't know if it's the lines or the columns or both that are < 1.

• The english word is "lines", not "ligns".

• Your checks are too complicated and redundants. The entire if/else block can be replaced by this:

    while(*line_count < 1)
    {
        printf("Error, number of lines < 1. \n");
        scanf("%d", line_count);
    }
  
  
    while(*column_count < 1)
    {
        printf("Error, number of colums < 1. \n");
        scanf("%d", column_count);
    }
  
    printf("Number of lines : %x, Number of columns : %x \n", *line_count, *column_count);