Add -h option

Makefile

@@ -6,7 +6,7 @@ SRC := $(wildcard src/*.c)
 OBJ := $(SRC:.c=.o)
 DEP := $(OBJ:.o=.d)
 PRE := $(wildcard sh/prev/*)
-GEN := gen/previews.h gen/server.h gen/helpers.h
+GEN := gen/help.h gen/previews.h gen/server.h gen/helpers.h
 
 LIBS := magic crypto
 
@@ -47,6 +47,7 @@ clean:
 docs: README.md doc/ctpv.1
 	deptable/list.awk $(PRE) | deptable/markdown.sed | deptable/insert.awk README.md
 	deptable/list.awk $(PRE) | deptable/roff.sed | deptable/insert.awk doc/ctpv.1
+	./genhelp.sh doc/ctpv.1 > help.txt
 
 ctpv: $(OBJ)
 	$(CC) -o $@ $+ $(ALL_LDFLAGS)
@@ -55,10 +56,13 @@ ctpv: $(OBJ)
 	$(CC) -o $@ $< -c $(ALL_CFLAGS)
 
 # Exclicit rules for generated header files
-src/ctpv.o: gen/previews.h
+src/ctpv.o: gen/previews.h gen/help.h
 src/shell.o: gen/helpers.h
 src/server.o: gen/server.h
 
+gen/help.h: help.txt embed/embed
+	embed/embed help.txt > $@
+
 gen/previews.h: $(PRE) embed/embed
 	embed/embed -p prev_scr_ $(PRE) > $@
 

doc/ctpv.1

@@ -18,6 +18,10 @@ ctpv \- terminal previewer
 .YS
 .
 .SY ctpv
+.B \-h
+.YS
+.
+.SY ctpv
 .B \-l
 .YS
 .
@@ -244,6 +248,10 @@ and standard error are printed.
 .SH OPTIONS
 .
 .TP
+.B \-h
+Print help message.
+.
+.TP
 .B \-l
 List all previews.
 .

genhelp.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+export GROFF_NO_SGR=1
+
+groff -t -man -mtty-char "$1" -Tascii |
+	col -bx |
+	sed '/OPTIONS/,/^[A-Z]/!d; /^[A-Z]/d'

help.txt

@@ -0,0 +1,14 @@
+       -h     Print help message.
+
+       -l     List all previews.
+
+       -m file ...
+              Print extension and MIME type of file.
+
+       -s id  Start server with ID id.
+
+       -c id  Send clear command to server with ID id (usually, it removes im-
+              age from terminal).
+
+       -e id  Kill server with ID id.
+

src/ctpv.c

@@ -16,6 +16,7 @@
 #include "preview.h"
 #include "../version.h"
 #include "../previews.h"
+#include "../gen/help.h"
 
 struct InputFile {
     char link[PATH_MAX], path[PATH_MAX];
@@ -392,6 +393,13 @@ static RESULT mime(int argc, char *argv[])
     return OK;
 }
 
+static RESULT help(void)
+{
+    printf("Usage: %s [OPTION]... FILE\n\n", program);
+    printf("Options:\n%s", help_txt);
+    return OK;
+}
+
 static RESULT version(void)
 {
     printf("%s version %s\n", program, VERSION);
@@ -405,8 +413,11 @@ int main(int argc, char *argv[])
     ctpv.opts.shell = "/bin/sh";
 
     int c;
-    while ((c = getopt(argc, argv, "s:c:e:lmv")) != -1) {
+    while ((c = getopt(argc, argv, "hs:c:e:lmv")) != -1) {
         switch (c) {
+        case 'h':
+            ctpv.mode = MODE_HELP;
+            break;
         case 's':
             ctpv.mode = MODE_SERVER;
             ctpv.server_id_s = optarg;
@@ -441,6 +452,9 @@ int main(int argc, char *argv[])
     case MODE_PREVIEW:
         ret = preview(argc, argv);
         break;
+    case MODE_HELP:
+        ret = help();
+        break;
     case MODE_SERVER:
         ret = server();
         break;

src/ctpv.h

@@ -6,6 +6,7 @@
 struct CTPV {
     enum {
         MODE_PREVIEW = 0, /* default mode */
+        MODE_HELP,
         MODE_SERVER,
         MODE_CLEAR,
         MODE_END,