Add man page

Makefile

@@ -4,32 +4,40 @@ SPWD_VERSION ?= $(shell git describe --tags)
 
 BUILD = build
 BIN = $(BUILD)/spwd
+MANPAGE= $(BUILD)/spwd.1
 
 CFLAGS += -Wall -Wextra -Wpedantic -O2
 OBJECTS := $(patsubst src/%.c,$(BUILD)/%.o,$(wildcard src/*.c))
 
-.DEFAULT_GOAL = test
+M4_DOCS = m4 -DSPWD_VERSION=$(SPWD_VERSION)
 
-$(BUILD)/USAGE.h: src/USAGE.m4
-	@mkdir -p $(dir $@)
-	m4 -DSPWD_VERSION=$(SPWD_VERSION) $< | xxd -i > $@
+.DEFAULT_GOAL = test
 
 $(BUILD)/%.o: src/%.c $(wildcard src/*.h) $(BUILD)/USAGE.h
 	@mkdir -p $(dir $@)
 	$(CC) $(CFLAGS) -c -o $@ $<
 
+$(BUILD)/USAGE.h: doc/USAGE.m4
+	@mkdir -p $(dir $@)
+	$(M4_DOCS) $< | xxd -i > $@
+
+$(MANPAGE): doc/spwd.1.scd
+	@mkdir -p $(dir $@)
+	$(M4_DOCS) $< | scdoc > $@
+
 $(BIN): $(OBJECTS)
 	@mkdir -p $(dir $@)
 	$(CC) $(CFLAGS) -g -o $@ $(OBJECTS)
 
 all: $(BIN)
 
 clean:
-	rm -f $(BIN) $(OBJECTS) $(BUILD)/USAGE.h
+	rm -f $(BIN) $(OBJECTS) $(BUILD)/USAGE.h $(MANPAGE)
 	rmdir $(BUILD)
 
-install: $(BIN)
+install: $(BIN) $(MANPAGE)
 	install -D -s -m 0755 -o root -g root $(BIN) $(DEST)/bin/spwd
+	install -D -m 0644 -o root -g root $(MANPAGE) $(DEST)/share/man/man1/spwd.1
 
 test: all
 	@./tests/run

doc/spwd.1.scd

@@ -0,0 +1,53 @@
+spwd(1) "ShorterPWD SPWD_VERSION" "User Commands"
+
+# NAME
+
+spwd - Shorter PWD
+
+# SYNOPSIS
+spwd [OPTION]...
+
+# DESCRIPTION
+
+Prints the current path, trimming the parents to fit a certain width. It is
+intended to be used in the prompt (*PS1* or equivalent).
+
+*-m* _width_
+	Target width of the path.
+
+*-a* _path-aliases_
+	Path for the aliases file.
+
+*-L*
+	use PWD from environment, even if it contains symlinks
+
+*-P*
+	use physical path, from *getcwd*(3)
+
+
+If no option is specified, -P is assumed.
+
+# ALIASES
+
+spwd can replace a path prefix with an alias. To use this feature, write the
+aliases in a file, and specify the path to it with the *-a* option. See
+*ALIASES FORMAT* below for a description of the format.
+
+# ALIASES FORMAT
+
+Every line in the file defines a new alias, with the following format:
+
+	alias = path
+
+Lines beginning with *#* are ignored. Spaces around *=* are stripped.
+
+# EXAMPLES
+
+Trim path to fit 40 characters:
+
+	PS1='$(spwd -m 40)\$ '
+
+
+# SEE ALSO
+
+*pwd*(1), *getcwd*(3)