diff options
Diffstat (limited to 'doc/q.manpage.1.ronn')
-rw-r--r-- | doc/q.manpage.1.ronn | 88 |
1 files changed, 0 insertions, 88 deletions
diff --git a/doc/q.manpage.1.ronn b/doc/q.manpage.1.ronn deleted file mode 100644 index 29d172b..0000000 --- a/doc/q.manpage.1.ronn +++ /dev/null @@ -1,88 +0,0 @@ - -q(1) -- Treating text as a database -=================================== - -## SYNOPSIS - -`q` [OPTIONS] <query> - -## DESCRIPTION -q allows performing SQL-like statements on tabular text data. Its purpose is to bring SQL expressive power to manipulating text data using the Linux command line. - -query should be an SQL-like query which contains filenames instead of table names (or - for stdin). - -If a header row exists (use -H flag to signify that), then column will be named using the header row values. Otherwise, columns will be named c1..cN. - -The delimiter can be set using the -d (or -t) option (use -D for setting the output delimiter). - -query should be enclosed in quotes, to make it one parameter. Please note that column names that include spaces need to be used in the query with back-ticks, as per the sqlite standard (e.g. `my column name`). - -All sqlite3 SQL constructs are supported, including joins across files (use an alias for each table). - -See https://github.com/harelba/q for more details. - -## EXAMPLES -Example 1: `ls -ltrd * | q "select c1,count(1) from - group by c1"` - This example would print a count of each unique permission string in the current folder. - -Example 2: `seq 1 1000 | q "select avg(c1),sum(c1) from -"` - This example would provide the average and the sum of the numbers in the range 1 to 1000 - -Example 3: `sudo find /tmp -ls | q "select c5,c6,sum(c7)/1024.0/1024 as total from - group by c5,c6 order by total desc"` - This example will output the total size in MB per user+group in the /tmp subtree - -## OPTIONS -* `-z` - Means that the file is gzipped. This is detected automatically if the file extension if .gz, but can be useful when reading gzipped data from stdin (since there is no content based detection for gzip) -* `-H <N>` - Tells q to skip N header lines in the beginning of the file - Used naturally for skipping a header line. This can possibly be detected automatically in the future. -* `-d` - Column/field delimiter. If it exists, then splitting lines will be done using this delimiter. If it doesn't, space will be used as the delimiter. If you need multi-character delimiters, run the tool with engine version 1 by adding `-E v1`. Using v1 will also revert to the old behavior where if no delimiter is provided, then any whitespace will be considered as a delimiter. -* `-D` - Column/field delimiter for output. If it exists, then the output will use this delimiter instead of the one used in input. Defaults to input delimiter if provided by `-d`, or space if not. -* `-t` - Shorthand flag for a tab delimiter, one header line format (Same as `-d $'\t' -H 1` - The $ notation is required so Linux would escape the tab...) -* `-f <F>` - Output-formatting option. If you don't like the output formatting of a specific column, you can use python formatting in order to change the output format for that column. See below for details -* `-e <E>` - Specify the text encoding. Defaults to UTF-8. If you have ASCII only text and want a 33% speedup, use `-e none`. Unfortunately, proper encoding/decoding has its price. -* `-b` - Beautify the output. If this flag exists, output will be aligned to the largest actual value of each column. **NOTE:** Use this only if needed, since it is slower and more CPU intensive. - -* `-A` - Analyze sample input and provide an analysis of column names and their detected types. Does not run the query itself -* `-m` - Data parsing mode. fluffy, relaxed or strict. In relaxed mode the -c column-count is optional. In strict mode, it must be provided. See separate section in the documentation about the various modes. Fluffy mode should only be used if backward compatibility (less well defined, but helpful...) to older versions of q is needed. -* `-c` - Specific column count. This parameter fixes the column count. In relaxed mode, this will cause missing columns to be null, and extra columns to be "merged" into the last column. In strict mode, any deviation from this column count will cause an error. -* `-k` - Keep leading whitespace. By default leading whitespace is removed from values in order to provide out-of-the-box usability. Using this flag instructs q to leave any leading whitespace in tact, making the output more strictly identical to the input. - -## FORMATTING OPTIONS -The format of F is as a list of X=f separated by commas, where X is a SELECTed column number and f is a python format (http://docs.python.org/release/2.4.4/lib/typesseq-strings.html) - -* Example: `-f "3=%-10s,5=%4.3f,1=%x"` - -## IMPLEMENTATION -The current implementation is written in Python using an in-memory database, in order to prevent the need for external dependencies. The implementation itself is pretty basic and supports only SELECT statements, including JOINs (Subqueries are supported only in the WHERE clause for now). In addition, error handling is really basic. However, I do believe that it can be of service even at that state. - -Please note that there is currently no checks and bounds on data size - It's up to the user to make sure things don't get too big. - -Please make sure to read the limitations section as well. - -## BUGS AND LIMITATIONS -The following limitations exist in the current implementation: - -* No checks and bounds on data size - -## FUTURE PLANS -* Smarter batch insertion to the database -* Faster reuse of previous data loading -* Allow working with external DB -* Real parsing of the SQL, allowing smarter execution of queries. -* Full Subquery support (will be possible once real SQL parsing is performed) -* Provide mechanisms beyond SELECT - INSERT and CREATE TABLE SELECT and such. - -## AUTHOR -Harel Ben-Attia (harelba@gmail.com) - -[@harelba](https://twitter.com/harelba) on Twitter - -Any feedback/suggestions/complaints regarding this tool would be much appreciated. Contributions are most welcome as well, of course. - -## COPYRIGHT -Copyright (C) 1988, 1998, 2000, 2002, 2004-2005, 2007-2014 Free Software Foundation, Inc. - -This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. - -This program is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA - - |