Updated February 2022; see History
SRCCOM {listfile=} oldfile, newfile {switches}
SRCCOM compares two source files, reporting the differences. This is useful, for example, when comparing two versions of a program to see what has changed between them. It is most useful when the differences between the files are few; when they are substantial, it becomes both overwhelmed and overwhelming.
Switch |
Effect |
|---|---|
/B |
Brief listing: same as /Q but without line numbers |
/Q |
Quick listing: list only the lines that differ between the two files |
/S |
Silent: ignores blank lines and whitespace differences |
/? |
Writes switch listing and usage info to the screen |
Under Unix, there is a much more powerful file comparison utility call diff, and in some cases, diff3, which can compare three files at a time. See the notes on DIFF, a A-Shell front-end to diff.
Note also that SRCCOM.LIT includes the list file name and switches in the listing header, matching the format of the AMOS version.
History
2021 December, A-Shell 6.5.1709: SRCCOM.LIT 2.0(201) rewritten to implement various improvements/fixes:
| • | No longer requires a memory partition of 1MB or more. |
| • | Supports a new switch /S which ignores whitespace differences. |
| • | Removed limit on line length, which previously was 512 characters. |
| • | Supports inserted blocks of up to 10000 lines, up from 750. |
| • | Reduces tendency for single-line "premature matches". For example, when a block of new code is inserted, SRCCOM previously would re-sync on a single line match (even a blank line) between the original code and the new code, causing the inserted block to appear like a fragmented series of multiple insertions instead of a single block. |
| • | Is now able to recognize "parallel differences" of up to 100 lines. These result from line changes rather than insertions/deletions. |
| • | The /Q mode now outputs the matching pair both before and after a set of differences. |
