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6.8. BSD-Diffutils main snapshot

BSD-Diffutils provides BSD-style file and directory difference tools, built here from the upstream main branch snapshot.

Input assumption: BSD-Diffutils-main.zip is already present in LBI_SOURCES from the chapter 4 source staging step.

Snapshot note: this package is built from main.zip, so upstream source content may change over time.

Licenses:

BSD-3-Clause

Dependencies:

musl (libc)
bmake (for building)
bheaded (for BSD compatibility headers)

BSD-Diffutils is a BSD-style diff and comparison utility set. we need it to provide file and directory comparison tools for later validation and maintenance steps in the book.

Extract and Enter the Source Tree

cd "$LBI_SOURCES"
unzip -q BSD-Diffutils-main.zip
cd BSD-Diffutils-main

Apply Compatibility and Layout Patches

sed -i \
    -e '1s|^#!/bin/ksh -$|#!/bin/sh|' \
    -e 's|^diff3prog=/usr/libexec/diff3prog$|diff3prog=/systembinaries/diff3prog|' \
    -e 's|^export PATH=.*$|export PATH=/binaries:/systembinaries:/bin:/usr/bin:/sbin:/usr/sbin|' \
    src/diff3/diff3.ksh

sed -i \
    's|${DESTDIR}/usr/bin/diff3|${DESTDIR}/system/binaries/diff3|' \
    src/diff3/Makefile

sed -i \
    's|char\\s*\\*splice(char \\*, char \\*);|char\t*diff_splice(char *, char *);|' \
    src/diff/diff.h

sed -i \
    's/\bsplice(/diff_splice(/g' \
    src/diff/diff.c src/diff/diffreg.c

sed -i \
    's/u_char ch, \\*p1, \\*p2;/unsigned char ch, *p1, *p2;/' \
    src/cmp/regular.c

Build BSD-Diffutils

CC="$LBI_ROOT/system/tools/bin/$LBI_TARGET-clang" \
CPPFLAGS="--target=$LBI_TARGET --sysroot=$LBI_ROOT -include ../../include/sys/cdefs.h" \
CFLAGS="--target=$LBI_TARGET --sysroot=$LBI_ROOT $LWI_CFLAGS" \
LDFLAGS="--target=$LBI_TARGET --sysroot=$LBI_ROOT $LBI_CUSTOM_LDFLAGS" \
bmake $LWI_MAKE_FLAGS

Install BSD-Diffutils

install -d "$LBI_ROOT/system/binaries"

for d in cmp diff sdiff; do
    CC="$LBI_ROOT/system/tools/bin/$LBI_TARGET-clang" \
    CPPFLAGS="--target=$LBI_TARGET --sysroot=$LBI_ROOT -include ../../include/sys/cdefs.h" \
    CFLAGS="--target=$LBI_TARGET --sysroot=$LBI_ROOT $LWI_CFLAGS" \
    LDFLAGS="--target=$LBI_TARGET --sysroot=$LBI_ROOT $LBI_CUSTOM_LDFLAGS" \
    bmake -C "src/$d" \
        DESTDIR="$LBI_ROOT" \
        BINDIR=/system/binaries \
        MANDIR=/system/documentation/man-pages \
        STRIP_FLAG= \
        BINOWN="$(id -un)" BINGRP="$(id -gn)" \
        MANOWN="$(id -un)" MANGRP="$(id -gn)" \
        install
done

CC="$LBI_ROOT/system/tools/bin/$LBI_TARGET-clang" \
CPPFLAGS="--target=$LBI_TARGET --sysroot=$LBI_ROOT -include ../../include/sys/cdefs.h" \
CFLAGS="--target=$LBI_TARGET --sysroot=$LBI_ROOT $LWI_CFLAGS" \
LDFLAGS="--target=$LBI_TARGET --sysroot=$LBI_ROOT $LBI_CUSTOM_LDFLAGS" \
bmake -C src/diff3 \
    DESTDIR="$LBI_ROOT" \
    BINDIR=/system/systembinaries \
    MANDIR=/system/documentation/man-pages \
    STRIP_FLAG= \
    BINOWN="$(id -un)" BINGRP="$(id -gn)" \
    MANOWN="$(id -un)" MANGRP="$(id -gn)" \
    install

Command Explanations

unzip -q BSD-Diffutils-main.zip: Extracts the upstream snapshot archive quietly.
sed -i ... src/diff3/diff3.ksh: Rewrites the helper script to use /bin/sh, the book's diff3prog location, and the target command search path.
sed -i ... src/diff3/Makefile: Changes the diff3 install path from the upstream /usr/bin default to /system/binaries.
sed -i ... src/diff/diff.h and sed -i ... src/diff/diff.c src/diff/diffreg.c: Rename the local splice helper so it does not collide with Linux's splice(2) declaration.
sed -i ... src/cmp/regular.c: Replaces the BSD u_char typedef with standard unsigned char for portability on musl.
CC="$LBI_ROOT/system/tools/bin/$LBI_TARGET-clang": Builds the target utilities with the target-prefixed Clang compiler.
CPPFLAGS="--target=$LBI_TARGET --sysroot=$LBI_ROOT -include ../../include/sys/cdefs.h": Targets the sysroot and force-includes the BSD compatibility cdefs.h header needed by this codebase.
CFLAGS and LDFLAGS: Keep compile and link steps on the target triple/sysroot while preserving local tuning variables.
bmake $LWI_MAKE_FLAGS: Uses BSD make because this project uses BSD-style makefiles, while still honoring the shared make parallelism setting.
install -d "$LBI_ROOT/system/binaries": Ensures the destination directory exists before package install rules run.
for d in cmp diff sdiff; do ... done: Installs the normal user-facing comparison tools with the same cross-build settings.
bmake -C "src/$d" ... install: Runs each utility's install rule from its own source directory.
BINDIR=/system/binaries and MANDIR=/system/documentation/man-pages: Override BSD make install destinations to match the book's layout.
STRIP_FLAG=: Prevents the install rule from stripping binaries automatically.
BINOWN, BINGRP, MANOWN, and MANGRP: Use the current user and group so the non-root install into LBI_ROOT succeeds.
bmake -C src/diff3 ... BINDIR=/system/systembinaries: Installs diff3prog support files into the system-binary directory where the patched script expects them.

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