add usage information - xscreenshot - screen capture tool
 (HTM) git clone git://git.codemadness.org/xscreenshot
 (DIR) Log
 (DIR) Files
 (DIR) Refs
 (DIR) README
 (DIR) LICENSE
       ---
 (DIR) commit 5e5fc6da22d1a496e21a52941af91f85b58186d2
 (DIR) parent 5f514c5284b3db94ecb4db1fea1e387d66ed4651
 (HTM) Author: Hiltjo Posthuma <hiltjo@codemadness.org>
       Date:   Mon, 28 Jul 2014 14:55:17 +0000
       
       add usage information
       
       Signed-off-by: Hiltjo Posthuma <hiltjo@codemadness.org>
       
       Diffstat:
         M xscreenshot.c                       |      12 +++++++++++-
       
       1 file changed, 11 insertions(+), 1 deletion(-)
       ---
 (DIR) diff --git a/xscreenshot.c b/xscreenshot.c
       @@ -93,6 +93,14 @@ pngstdout(XImage *img)
                png_destroy_write_struct(&png_struct_p, NULL);
        }
        
       +static void
       +usage(void)
       +{
       +        die("xscreenshot-" VERSION
       +            ", (c) 2014 xscreenshot engineers, see LICENSE for details\n"
       +            "usage: xscreenshot [winid]");
       +}
       +
        int
        main(int argc, char *argv[])
        {
       @@ -107,10 +115,12 @@ main(int argc, char *argv[])
        
                /* win */
                if(argc > 1) {
       +                if(strcmp(argv[1], "-h") == 0 || strcmp(argv[1], "-v") == 0)
       +                        usage();
                        errno = 0;
                        win = (Window)strtol(argv[1], NULL, 0);
                        if(errno != 0)
       -                        die("input not a number");
       +                        usage();
                } else {
                        win = RootWindow(dpy, 0);
                }