pawk 0.6.3

AWK example translations

Most basic AWK constructs are available. You can find more idiomatic examples below in the example section, but here are a bunch of awk commands and their equivalent pawk commands to get started with:

Print lines matching a pattern:

ls -l / | awk '/etc/'
ls -l / | pawk '/etc/'

Print lines not matching a pattern:

ls -l / | awk '!/etc/'
ls -l / | pawk '!/etc/'

Field slicing and dicing (here pawk wins because of Python’s array slicing):

ls -l / | awk '/etc/ {print $5, $6, $7, $8, $9}'
ls -l / | pawk '/etc/ f[4:]'

Begin and end end actions (in this case, summing the sizes of all files):

ls -l | awk 'BEGIN {c = 0} {c += $5} END {print c}'
ls -l | pawk -B 'c = 0' -E 'c' 'c += int(f[4])'

Print files where a field matches a numeric expression (in this case where files are > 1024 bytes):

ls -l | awk '$5 > 1024'
ls -l | pawk 'int(f[4]) > 1024'

Matching a single field (any filename with “t” in it):

ls -l | awk '$NF ~/t/'
ls -l | pawk '"t" in f[-1]'

pip install pawk

Line actions

The type of the evaluated expression determines how output is displayed:

• tuple or list: the elements are converted to strings and joined with the output delimiter (-O).

• None or False: nothing is output for that line.

• True: the original line is output.

• Any other value is converted to a string.

Start/end blocks

The rules are the same as for line actions with one difference. Because there is no “line” that corresponds to them, an expression returning True is ignored.

$ echo -ne 'foo\nbar' | pawk -E t
foo
bar

Usage: cat input | pawk [<options>] <expr>

A Python line-processor (like awk).

See https://github.com/alecthomas/pawk for details. Based on
http://code.activestate.com/recipes/437932/.

Options:
  -h, --help            show this help message and exit
  -I <filename>, --in_place=<filename>
                        modify given input file in-place
  -i <modules>, --import=<modules>
                        comma-separated list of modules to "from x import *"
                        from
  -F <delim>            input delimiter
  -O <delim>            output delimiter
  -L <delim>            output line separator
  -B <statement>, --begin=<statement>
                        begin statement
  -E <statement>, --end=<statement>
                        end statement
  -s, --statement       DEPRECATED. retained for backward compatibility
  --strict              abort on exceptions

Line processing

Print the name and size of every file from stdin:

find . -type f | pawk 'f[0], os.stat(f[0]).st_size'

**Note:** this example also shows how pawk automatically imports
referenced modules, in this case ``os``.

Print the sum size of all files from stdin:

find . -type f | \
    pawk \
        --begin 'c=0' \
        --end c \
        'c += os.stat(f[0]).st_size'

Short-flag version:

find . -type f | pawk -B c=0 -E c 'c += os.stat(f[0]).st_size'

Whole-file processing

If you do not provide a line expression, but do provide an end statement, pawk will accumulate each line, and the entire file’s text will be available in the end statement as t. This is useful for operations on entire files, like the following example of converting a file from markdown to HTML:

cat README.md | \
    pawk --end 'markdown.markdown(t)'

Short-flag version:

cat README.md | pawk -E 'markdown.markdown(t)'