How to use the command 'ptx' (with examples)

The ‘ptx’ command is used to generate a permuted index of words from one or more text files. It provides various options to customize the index output, such as specifying index references, generating references automatically, setting a fixed width for output, filtering words, and using SYSV-style behaviors.

Use case 1: Generate a permuted index where the first field of each line is an index reference

Code:

ptx --references path/to/file

Motivation: This use case is helpful when you want to generate an index with custom index references that can refer to different sections or parts of the text document.

Explanation:

• ptx: The command itself.
• --references: This option instructs ‘ptx’ to generate a permuted index with index references.
• path/to/file: The location of the input text file.

Example output:

1: apple:   Lorem ipsum dolor sit amet
2: banana:  consectetur adipiscing elit, sed
3: cherry:  do eiusmod tempor incididunt

Use case 2: Generate a permuted index with automatically generated index references

Code:

ptx --auto-reference path/to/file

Motivation: This use case is useful when you don’t need custom index references and want ‘ptx’ to automatically generate them for you.

Explanation:

• ptx: The command itself.
• --auto-reference: This option tells ‘ptx’ to generate a permuted index with automatically generated index references.
• path/to/file: The location of the input text file.

Example output:

PT01: apple:   Lorem ipsum dolor sit amet
PT02: banana:  consectetur adipiscing elit, sed
PT03: cherry:  do eiusmod tempor incididunt

Use case 3: Generate a permuted index with a fixed width

Code:

ptx --width=width_in_columns path/to/file

Motivation: This use case is beneficial when you want to have a consistent width for the output, useful for aligning columns or when integrating the index with other tools or systems.

Explanation:

• ptx: The command itself.
• --width=width_in_columns: This option specifies the width of each line in columns.
• path/to/file: The location of the input text file.

Example output:

apple     : Lorem ipsum dolor sit amet
banana    : consectetur adipiscing elit, sed
cherry    : do eiusmod tempor incididunt

Use case 4: Generate a permuted index with a list of filtered words

Code:

ptx --only-file=path/to/filter path/to/file

Motivation: This use case allows you to generate a permuted index by filtering specific words, which is useful if you only want to include certain terms in the generated index.

Explanation:

• ptx: The command itself.
• --only-file=path/to/filter: This option specifies a file containing a list of words to be filtered.
• path/to/file: The location of the input text file.

Example output:

banana: consectetur adipiscing

Use case 5: Generate a permuted index with SYSV-style behaviors

Code:

ptx --traditional path/to/file

Motivation: This use case is essential when you want to use SYSV-style behaviors for generating the permuted index, which may be required for compatibility with legacy systems or specific applications.

Explanation:

• ptx: The command itself.
• --traditional: This option enables SYSV-style behaviors.
• path/to/file: The location of the input text file.

Example output:

apple
banana
cherry

Conclusion

The ‘ptx’ command is a versatile tool for generating permuted indexes from text files. It offers various options to customize the output, including index references, width, filtering, and SYSV-style behaviors. By understanding these different use cases, you can utilize the ‘ptx’ command to generate permuted indexes tailored to your specific requirements.