# xan cat ```txt Concatenates CSV data by column or by row. When concatenating by column, the columns will be written in the same order as the inputs given. The number of rows in the result is always equivalent to to the minimum number of rows across all given CSV data. (This behavior can be reversed with the '--pad' flag.) When concatenating by row, all CSV data must have the same number of columns. If you need to rearrange the columns or fix the lengths of records, use the 'select' or 'fixlengths' commands. Also, only the headers of the *first* CSV data given are used. Headers in subsequent inputs are ignored. (This behavior can be disabled with --no-headers.) When concatenating a large number of CSV files exceeding your shell's command arguments limit, prefer using the --paths flag to read the list of CSV files to concatenate from input lines or from a CSV file containing paths in a column given to the --path-column flag. Feeding --paths lines: $ xan cat rows --paths paths.txt > concatenated.csv Feeding --paths CSV file: $ xan cat rows --paths files.csv --path-column path > concatenated.csv Feeding stdin ("-") to --paths: $ find . -name '*.csv' | xan cat rows --paths - > concatenated.csv Feeding CSV as stdin ("-") to --paths: $ cat filelist.csv | xan cat rows --paths - --path-column path > concatenated.csv Usage: xan cat rows [options] [...] xan cat (cols|columns) [options] [...] xan cat --help cat cols/columns options: -p, --pad When concatenating columns, this flag will cause all records to appear. It will pad each row if other CSV data isn't long enough. cat rows options: --paths When concatenating rows, give a text file (use "-" for stdin) containing one path of CSV file to concatenate per line. --path-column When given a column name, --paths will be considered as CSV, and paths to CSV files to concatenate will be extracted from the selected column. -S, --source-column Name of a column to prepend in the output of "cat rows" indicating the path to source file. Common options: -h, --help Display this message -o, --output Write output to instead of stdout. -n, --no-headers When set, the first row will NOT be interpreted as column names. Note that this has no effect when concatenating columns. -d, --delimiter The field delimiter for reading CSV data. Must be a single character. ```