# cut ``` cut OPTION... [FILE]... ``` Prints specified byte or field columns from each line of stdin or the input files ## After Help Each call must specify a mode (what to use for columns), a sequence (which columns to print), and provide a data source ### Specifying a mode Use `--bytes` (`-b`) or `--characters` (`-c`) to specify byte mode Use `--fields` (`-f`) to specify field mode, where each line is broken into fields identified by a delimiter character. For example for a typical CSV you could use this in combination with setting comma as the delimiter ### Specifying a sequence A sequence is a group of 1 or more numbers or inclusive ranges separated by a commas. ``` cut -f 2,5-7 some_file.txt ``` will display the 2nd, 5th, 6th, and 7th field for each source line Ranges can extend to the end of the row by excluding the second number ``` cut -f 3- some_file.txt ``` will display the 3rd field and all fields after for each source line The first number of a range can be excluded, and this is effectively the same as using 1 as the first number: it causes the range to begin at the first column. Ranges can also display a single column ``` cut -f 1,3-5 some_file.txt ``` will display the 1st, 3rd, 4th, and 5th field for each source line The `--complement` option, when used, inverts the effect of the sequence ``` cut --complement -f 4-6 some_file.txt ``` will display the every field but the 4th, 5th, and 6th ### Specifying a data source If no `sourcefile` arguments are specified, stdin is used as the source of lines to print If `sourcefile` arguments are specified, stdin is ignored and all files are read in consecutively if a `sourcefile` is not successfully read, a warning will print to stderr, and the eventual status code will be 1, but cut will continue to read through proceeding `sourcefiles` To print columns from both STDIN and a file argument, use `-` (dash) as a `sourcefile` argument to represent stdin. ### Field Mode options The fields in each line are identified by a delimiter (separator) #### Set the delimiter Set the delimiter which separates fields in the file using the `--delimiter` (`-d`) option. Setting the delimiter is optional. If not set, a default delimiter of Tab will be used. If the `-w` option is provided, fields will be separated by any number of whitespace characters (Space and Tab). The output delimiter will be a Tab unless explicitly specified. Only one of `-d` or `-w` option can be specified. This is an extension adopted from FreeBSD. #### Optionally Filter based on delimiter If the `--only-delimited` (`-s`) flag is provided, only lines which contain the delimiter will be printed #### Replace the delimiter If the `--output-delimiter` option is provided, the argument used for it will replace the delimiter character in each line printed. This is useful for transforming tabular data - e.g. to convert a CSV to a TSV (tab-separated file) ### Line endings When the `--zero-terminated` (`-z`) option is used, cut sees \\0 (null) as the 'line ending' character (both for the purposes of reading lines and separating printed lines) instead of \\n (newline). This is useful for tabular data where some of the cells may contain newlines ``` echo 'ab\\0cd' | cut -z -c 1 ``` will result in 'a\\0c\\0'