--- title: File types description: Give ThinkThen text from a pipe or a file, one item per line, a CSV, TSV or Excel file, or many files in one command. goal: The reader gets their own text into the command in the right shape and knows where each answer goes. reader: A command-line user with messages in a pipe, a text file, a CSV, TSV or Excel file, or many files kind: how-to verified: 2026-11-03 --- # File types Every function reads the text to judge from a pipe, from `--text`, or from files. It reads plain text, one item per line, CSV, TSV and Excel files, and many files in one command. ```sh echo 'Please refund my order.' | thinkthen decide 'Does the customer request a refund?' ``` Output ```text true ``` Yes: the message asks for a refund. A pipe is one text, and its answer is one line. `--text 'Please refund my order.'` does the same without a pipe, and a file name after the question reads that file as one text. ## Judge each line `--from lines` makes each line its own text. This file holds three messages: ```text title="messages.txt" Please refund my order. Where is my parcel? I was charged twice for one invoice. ``` ```sh thinkthen decide --from lines \ 'Does the customer request a refund?' messages.txt ``` Output ```text 1 true 2 false 3 true ``` Lines 1 and 3 ask for a refund. Each answer starts with the line's number and a tab. Blank lines are skipped. filter, rank and annotate read lines without `--from lines`; the other functions read the whole input as one text. ## Add an answer column to a CSV file A CSV file is a table of text with a header line. Name the column to judge with `--column`, and the new answer column with `--into`. ```csv title="messages.csv" id,text a1,Please refund my order. a2,Where is my parcel? a3,I was charged twice for one invoice. ``` ```sh thinkthen decide 'Does the customer request a refund?' \ --from csv --column text --into is_refund < messages.csv ``` Output ```text id,text,is_refund a1,Please refund my order.,TRUE a2,Where is my parcel?,FALSE a3,I was charged twice for one invoice.,TRUE ``` The same table comes back with an `is_refund` column. Excel reads `TRUE` and `FALSE` as yes and no. A not sure answer, or a row that failed, leaves the cell empty, so it never reads as a no. Each failed row is named on standard error, and the command exits 6 ([Exit codes](/command-line/exit-codes/)). Where the new table goes depends on how you give the file: | You give | The new table goes to | | --- | --- | | `--from csv < messages.csv` | the screen, as above | | `messages.csv` | a new file beside it, `messages.thinkthen.csv`, and the command prints that name | | `messages.csv --output reviewed.csv` | `reviewed.csv` | | `messages.csv --in-place` | `messages.csv` itself, after it keeps the original as `messages.backup.csv`. If filter fails on any row, `messages.csv` stays as it was and the command exits 6 | ThinkThen never overwrites an output file. If `messages.thinkthen.csv` already exists, the command stops with exit code 2; choose a new `--output` name or remove the old file. Repeat `--column` to judge several columns of each row together. `--details` adds five more columns for each answer, such as its status and probability. ## Read a TSV file A TSV file is a CSV file with tabs between the columns. Use `--from tsv`, or name a file that ends in `.tsv`. ```text title="messages.tsv" id text a1 Please refund my order. a2 Where is my parcel? a3 I was charged twice for one invoice. ``` ```sh thinkthen decide 'Does the customer request a refund?' \ --from tsv --column text --into is_refund < messages.tsv ``` Output ```text id text is_refund a1 Please refund my order. TRUE a2 Where is my parcel? FALSE a3 I was charged twice for one invoice. TRUE ``` The same table comes back, with tabs, and the `is_refund` column added. ## Add an answer column to an Excel file An Excel file (`.xlsx`) works by name, never from a pipe. This workbook holds one worksheet, `Messages`: messages.xlsx, worksheet Messages: | id | text | | --- | --- | | a1 | Please refund my order. | | a2 | Where is my parcel? | | a3 | I was charged twice for one invoice. | ```sh thinkthen decide 'Does the customer request a refund?' \ messages.xlsx --column text --into is_refund ``` Output ```text messages.thinkthen.xlsx ``` The command writes `messages.thinkthen.xlsx` beside the input and prints its name. Its `is_refund` column holds real `TRUE` and `FALSE` cells, and `#N/A` for not sure or a failed message, so an Excel formula can't mistake either for a no. Every other worksheet, style and formula stays as it was. When a workbook holds more than one worksheet, name one with `--sheet Messages`. Formula cells are read from their saved values and never recalculated. Older `.xls` files, macro-enabled workbooks and signed workbooks are refused; save an unsigned `.xlsx` copy first. ## Judge many files at once Name every file after the question. Here the shell expands `messages/*.txt` to three files, each holding one message: ```text title="messages/a1.txt" Please refund my order. ``` ```text title="messages/a2.txt" Where is my parcel? ``` ```text title="messages/a3.txt" I was charged twice for one invoice. ``` ```sh thinkthen decide 'Does the customer request a refund?' \ messages/*.txt ``` Output ```text messages/a1.txt true messages/a2.txt false messages/a3.txt true ``` `a1` and `a3` ask for a refund. Each file is one text, and each answer starts with its file name and a tab. Add `-` among the files to read the pipe too. A CSV, TSV or Excel file goes alone, one per command. ## How ThinkThen picks the type A file's ending picks its type: `.csv`, `.tsv`, `.xlsx` and `.jsonl`. Anything else, and a pipe, is plain text. `--from` names the type outright: `text`, `lines`, `jsonl`, `csv`, `tsv` or `xlsx`. In a script, say `--from` so the type never depends on a file's name. [JSON Lines](/command-line/json-lines/) covers `.jsonl` files. ## Next [JSON Lines](/command-line/json-lines/) judges one field of each JSON object and adds the answer to it.