Agenda
- Patches
- Text file diffs
- Patch management
- Quilt
- Quilt Concepts
- Quilt Usage
- Quilt Demonstration
- Summary
- Questions
Text file diffs
- What: a file containing a minimal representation of differences between one or more files
- What for: creating & maintaining source changes
- How:
diff,patch... (POSIX.1 standard tools) - Types: 'normal', unified context, rcs, copied context...
Example 1: 'normal' diff
$ cat numbers.txt $ cat numbers.txt.new [...] [...] 6 6 7 7 8 8 9 9 1 -> 0 1 1 2 2 3 3 4 4 [...] [...]
$ diff numbers.txt numbers.txt.new 11c11 < 1 --- > 0
Example 2: copied context diff
$ diff -c numbers.txt numbers.txt.new *** numbers.txt 2005-07-01 00:34:56.120398334 +0200 --- numbers.txt.new 2005-07-01 00:34:49.728125967 +0200 *************** *** 8,14 **** 7 8 9 ! 1 1 2 3 --- 8,14 ---- 7 8 9 ! 0 1 2 3
Example 3: unified context diff
$ diff -u /home/user1/dev/quilt/numbers.txt* --- /home/user1/dev/quilt/numbers.txt 2005-07-01 00:34:56.120398334 +0200 +++ /home/user1/dev/quilt/numbers.txt.new 2005-07-01 00:34:49.728125967 +0200 @@ -8,7 +8,7 @@ 7 8 9 -1 +0 1 2 3Non POSIX.1 standard but most commonly used
Using Patch
usually patch [options] < patchfile
- patch strip level.
-pnumor--strip num: strips smallest prefix containingnumslashes.
With/home/user1/dev/quilt/numbers.txtvalue result numbers.txt -p0 /home/user1/dev/quilt/numbers.txt -p4 quilt/numbers.txt -d dir: changes to specified directory.
Typical patch life cycle
Working with a single patch is usually easy!
- someone generates/updates the patch:
diff,cvs diff [-u]*,svn diff... - someone applies patch:
patch
Patch management is harder
- 'out of tree' life: patches are queued (up to 1000+), updated, discarded, reordered...
- affects both maintainer and developer
Patch Storage Strategies
package.tar.gz+ |
|
$ cat patches/patch1.diff Fixes some typos. Jerome Lacoste (jerome@coffeebreaks.org) Index: code/cocktails/five_dominos.txt =================================================================== --- code.orig/cocktails/five_dominos.txt 2005-06-30 23:38:33.061492249 +0200 +++ code/cocktails/five_dominos.txt 2005-06-30 23:39:24.921589010 +0200 @@ -1,4 +1,4 @@ -Boisson de base: rhum blan +Boisson de base: rhum blanc Puissance: 6 Se prepare: au shaker Se sert: dans une coupe
Patch Management Stragegies
| limitations | |
|---|---|
| multiple copies of source trees + manual editing | error prone, not scalable |
| multiple copies of source trees + custom scripts | portable?, completeness? |
| version control systems | system requirements, overhead, switching between patches still hard... |
Agenda
- Patches
- Text file diffs
- Patch management
- Quilt
- Quilt Concepts
- Quilt Usage
- Quilt Demonstration
- Summary
- Questions
Quilt
- a personal patch management tool (does not replace your version control system)
- license: GPL
- origin: Andrew Morton's patch-scripts
- maintained by Andreas Gruenbacher
- design: set of bash scripts
- dependencies: GNU tools (diff, patch, gawk), [sendmail], [graphviz]
- environment: Unices (on Windows using MSYS but not Cygwin)
Quilt: concepts and features
- syntax
quilt {command} [options] [arguments] - stack of patches (pop/push operations)
- backs-up modified files
- operations on topmost [or specified] patch
- handles strip levels (default
-p1) - customizable through environment variables
Quilt: structure
- default directory layout
work/ -+- ... +- patches/-+- series | |- patch1.diff | |- patch2.diff | +- ... +- .pc/-+- applied-patches | |- patch1.diff/ -+- ... | |- patch2.diff/ -+- ... | +- ... - series file
# comment patch1.diff #patch2.diff patch3.diff # patch comment patch4.diff -p2
Quilt main commands
Developing a patch
- create a new patch:
new {patchName} - add file(s) to a patch:
add {filePath} - manual edit
- update patch:
refresh - list files in patch:
files - show patch:
diff - remove file(s) from a patch:
remove {filePath}
Managing patches: basics
- apply one/all:
push [-f] [-a] - unapply one/all:
pop [-f] [-a] - remove unapplied patch:
delete [patchName] - list all patch names in series:
series - show applied/unapplied patch names:
applied/unapplied - show previous, topmost, next patch name:
previous,top,next - create (graphviz) dependency graph:
graph - list patches modifying file:
patches {filePath}
Quilt graph output
Example of patch dependencies graph
Managing patches: advanced
Helper/Shortcuts- add + edit in
$EDITOR([vi]):edit - rename a patch:
rename - import/incorporate patches:
import [-f]/fold - duplicate a patch:
fork - prepare or send emails:
mail - search in files (skip
.pcandpatches):grep - create a reversible snapshot:
snapshot - initialize from RPM spec or series file:
setup
Quilt: Distributing patches
Various options
- create a single patch using
diff --combine {patchName} - distribute the
patchessub-directory content
Quilt
| Demo |
Agenda
- Patches
- Text file diffs
- Patch management
- Quilt
- Quilt Concepts
- Quilt Usage
- Quilt Demonstration
- Summary
- Questions
Pitfalls, tips and limitations
- use short command names
- mistake? start from scratch: pop all and delete the
.pcsub-directory. - do not fear to modify the
seriesfile. - no support for patch reordering
- no support for binary files
- no IDE integration
- only a single snapshot currently supported
- support coming on Windows
Related tool: gquilt
a PyGTK GUI wrapper for main quilt commands
Summary
- simple concept, simple implementation
- operations on multiple patches made easy
- patch management independent of your source control
- useful for developers and maintainers of FOSS tools
- active community
Links
More information- http://savannah.nongnu.org/projects/quilt/
- quilt PDF document
quilt {command} -h- POSIX.1 standard, shell and utilities
- quilt for Windows
- gquilt
- other patch tools: patchutils, PatchMaker
Questions
| ? |