How to parse the contents of a file?

Messi,
Your requests are not consistent. This formum is not intended for coding solutions to meet everyone's needs, we are simply here to provide help and suggestions to get you started. Your original posts did not show you had commas in your input. One of your other posts indicated you just wanted to write the data back to a file. Yet another post said you wanted the data in a table. Now it becomes apparent that you want your data in a table, you want to write it to a file in nearly the same format as it came in with better tabulation and now your input has commas. You also mentioned your code was failing but never pasted any code.

Some comments based on your last three posts:
If you want to throw out your header line you can add a line before you add data to the table:
     when(tokens
        unless(car(tokens)=="RULE"
           table[car(tokens)] = cdr(tokens)
        )
      )

Tables do not maintain order like lists do, but they are much more efficient. If your rules are in alphabetical order, then they can be sorted before you print them out. I simply used the printstruct command to show the contents of the table. If you want to write the data back out to a file in a "cleaner" format, you can write it out as you read it in AND store it in a table to be used later in your session. If you want to loop through the table and write the data out, the best you can do is sort the keys of the table.
foreach(key sort(table~>? 'alphalessp)
    printf("%-10s:    %L\n" key table[key])
)

As far as the format of the output, when you started using a parseString with commas, you end up leaving all of the spaces in the data. Doing a parseString on the whitespace (no arguments after the string), will get rid of the extra space, but will split stuff like "POLY WIDTH" into two separate list items. If all you are doing is reading in a text file and writing it back out, Skill is NOT the ideal language for this. In this case, if you must use commas, you'll probably want to get familiar with commands like rexCompile and rexReplace so that you can remove leading spaces.

a="    MY RULE"
rexCompile("^ *")
b=rexReplace(a "" 0)

Another option is to use: buildString(parseString(a))
This parses out the spaces and rebuilds the string with only one space between each word.

Example:
rexCompile("^ *")
foreach(key sort(table~>? 'alphalessp)
    printf("%s:\t" key)
    foreach(col table[key]
        col = rexReplace(col "" 0)
        printf("%-15s \n" col)
    )
    printf("\n")
)

So a final solution could be:
procedure(parseFile( @optional (ipFile "/tmp/rule.txt" ))
  let( ( tokens table fpFile value key line)
    table = makeTable("ruleTable" nil)
    fpFile = infile( ipFile )
    while( gets( line fpFile )
      tokens = parseString( line ",")
      when(tokens
        value = nil
        unless(rexMatchp("RULE NO" car(tokens))
          rexCompile("^ *")
          key = rexReplace(car(tokens) "" 0)
          foreach(col cdr(tokens)
              col = buildString(parseString(col))
              value = append1(value col)
          )
          when(key && value
              table[key] = value
          )
        )
      )
    ) ;while file
    close( fpFile )
    foreach(key sort(table~>? 'alphalessp)
        printf("%s:  " key)
        foreach(col table[key]
            printf("%-15s " col)
        )
        printf("\n")
    )
    table
  ) ;let
) ;procedure

Derek

Messi,
Your requests are not consistent. This formum is not intended for coding solutions to meet everyone's needs, we are simply here to provide help and suggestions to get you started. Your original posts did not show you had commas in your input. One of your other posts indicated you just wanted to write the data back to a file. Yet another post said you wanted the data in a table. Now it becomes apparent that you want your data in a table, you want to write it to a file in nearly the same format as it came in with better tabulation and now your input has commas. You also mentioned your code was failing but never pasted any code.

Some comments based on your last three posts:
If you want to throw out your header line you can add a line before you add data to the table:
     when(tokens
        unless(car(tokens)=="RULE"
           table[car(tokens)] = cdr(tokens)
        )
      )

Tables do not maintain order like lists do, but they are much more efficient. If your rules are in alphabetical order, then they can be sorted before you print them out. I simply used the printstruct command to show the contents of the table. If you want to write the data back out to a file in a "cleaner" format, you can write it out as you read it in AND store it in a table to be used later in your session. If you want to loop through the table and write the data out, the best you can do is sort the keys of the table.
foreach(key sort(table~>? 'alphalessp)
    printf("%-10s:    %L\n" key table[key])
)

As far as the format of the output, when you started using a parseString with commas, you end up leaving all of the spaces in the data. Doing a parseString on the whitespace (no arguments after the string), will get rid of the extra space, but will split stuff like "POLY WIDTH" into two separate list items. If all you are doing is reading in a text file and writing it back out, Skill is NOT the ideal language for this. In this case, if you must use commas, you'll probably want to get familiar with commands like rexCompile and rexReplace so that you can remove leading spaces.

a="    MY RULE"
rexCompile("^ *")
b=rexReplace(a "" 0)

Another option is to use: buildString(parseString(a))
This parses out the spaces and rebuilds the string with only one space between each word.

Example:
rexCompile("^ *")
foreach(key sort(table~>? 'alphalessp)
    printf("%s:\t" key)
    foreach(col table[key]
        col = rexReplace(col "" 0)
        printf("%-15s \n" col)
    )
    printf("\n")
)

So a final solution could be:
procedure(parseFile( @optional (ipFile "/tmp/rule.txt" ))
  let( ( tokens table fpFile value key line)
    table = makeTable("ruleTable" nil)
    fpFile = infile( ipFile )
    while( gets( line fpFile )
      tokens = parseString( line ",")
      when(tokens
        value = nil
        unless(rexMatchp("RULE NO" car(tokens))
          rexCompile("^ *")
          key = rexReplace(car(tokens) "" 0)
          foreach(col cdr(tokens)
              col = buildString(parseString(col))
              value = append1(value col)
          )
          when(key && value
              table[key] = value
          )
        )
      )
    ) ;while file
    close( fpFile )
    foreach(key sort(table~>? 'alphalessp)
        printf("%s:  " key)
        foreach(col table[key]
            printf("%-15s " col)
        )
        printf("\n")
    )
    table
  ) ;let
) ;procedure

Derek