fixcvsdiff

fixcvsdiff [options]

Commonly used in a pipeline:
cvs diff -u [cvs_options] | fixcvsdiff

(No specific functional parameters)
    fixcvsdiff typically operates as a simple filter, reading from standard input and writing to standard output without requiring specific command-line options for its core functionality. It may support standard options like --help or --version.

fixcvsdiff is a specialized utility designed to normalize and correct inconsistencies in the output generated by the cvs diff -u command (unified diff format). These inconsistencies, often related to timestamp precision, format variations, or minor structural quirks, can pose problems for automated tools attempting to parse or apply these diffs.

Primarily developed as an internal component of repository migration tools like cvs2svn, fixcvsdiff ensures that the CVS diff output adheres to a more predictable and standardized format. This sanitization is crucial for maintaining data integrity and ensuring successful processing when converting CVS repositories to other version control systems such as Git or Subversion. It typically operates as a filter, reading diff data from standard input and writing the corrected output to standard output.

• fixcvsdiff is not a general-purpose diff fixing tool; it is specifically tailored to address known quirks in cvs diff -u output, particularly related to timestamps and header formatting.
• It is often bundled with or used as part of larger repository migration suites (e.g., cvs2svn), rather than being a standalone system utility.
• Its relevance is diminishing as CVS usage declines in favor of more modern version control systems like Git.

fixcvsdiff is commonly employed within shell scripts or automated workflows where cvs diff output needs to be processed programmatically. For example, to generate a clean diff between two tags:

cvs diff -u -r TAG1 -r TAG2 module_name | fixcvsdiff > clean_diff.patch

This ensures that the clean_diff.patch file is free from common CVS diff inconsistencies, making it easier to apply with tools like patch(1) or parse with custom scripts.

fixcvsdiff emerged as a necessary component within projects focused on migrating CVS repositories to other version control systems, most notably cvs2svn. The motivation was to overcome parsing challenges posed by slight variations and inconsistencies in cvs diff -u output that could cause conversion failures or data integrity issues. It was developed to specifically preprocess these diffs, making them robust enough for automated parsing and application during the migration process. Its primary development and maintenance have been tied to these migration tools, evolving to handle specific CVS output nuances.

cvs(1), diff(1), patch(1), cvs2svn, cvs-fast-export