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author | Luke Shumaker <lukeshu@sbcglobal.net> | 2017-01-30 19:27:36 -0500 |
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committer | Luke Shumaker <lukeshu@sbcglobal.net> | 2017-01-30 19:27:36 -0500 |
commit | ba1cae8a6dc3c4860df236e82055f5b01f8f3ff0 (patch) | |
tree | e5ea01166d6e92e5454905b3b993489cab677e5d /build-aux/Makefile.once.head/10-write-ifchanged.mk | |
parent | 78705062cfd1a17db1ef994ee6c48925060c6f29 (diff) | |
parent | 16e8d3b92b5e35a5eaee40a7b7fc0279c342886a (diff) |
Merge remote-tracking branch 'autothing/v3/master'
Diffstat (limited to 'build-aux/Makefile.once.head/10-write-ifchanged.mk')
-rw-r--r-- | build-aux/Makefile.once.head/10-write-ifchanged.mk | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/build-aux/Makefile.once.head/10-write-ifchanged.mk b/build-aux/Makefile.once.head/10-write-ifchanged.mk new file mode 100644 index 0000000..649aab9 --- /dev/null +++ b/build-aux/Makefile.once.head/10-write-ifchanged.mk @@ -0,0 +1,23 @@ +mod.write-ifchanged.description = `write-ifchanged` auxiliary build script +mod.write-ifchanged.files += $(topsrcdir)/build-aux/write-ifchanged +define mod.write-ifchanged.doc +# User variables: +# - `WRITE_IFCHANGED ?= $(topsrcdir)/build-aux/write-ifchanged` +# Inputs: +# (none) +# Outputs: +# (none) +# +# The $(WRITE_IFCHANGED) program reads a file from stdin, and writes it to the +# file named in argv[1], but does so atomically, but more importantly, does so +# in a way that does not bump the file's ctime if the new content is the same +# as the old content. +# +# That is, the following lines are almost equivalient: +# +# ... > $@ +# ... | $(WRITE_ATOMIC) $@ +endef +mod.write-ifchanged.doc := $(value mod.write-ifchanged.doc) + +WRITE_IFCHANGED ?= $(topsrcdir)/build-aux/write-ifchanged |