Extended documentation for output format in README (Closes #268)

README.md

@@ -108,6 +108,28 @@ which means you can modify it, redistribute it or use it however you like.
 
 You can configure youtube-dl by placing default arguments (such as `--extract-audio --no-mtime` to always extract the audio and not copy the mtime) into `/etc/youtube-dl.conf` and/or `~/.local/config/youtube-dl.conf`.
 
+# OUTPUT TEMPLATE
+
+The `-o` option allows users to indicate a template for the output file names. The basic usage is not to set any template arguments when downloading a single file, like in `youtube-dl -o funny_video.flv "http://some/video"`. However, it may contain special sequences that will be replaced when downloading each video. The special sequences have the format `%(NAME)s`. To clarify, that is a percent symbol followed by a name in parenthesis, followed by a lowercase S. Allowed names are:
+
+ - `id`: The sequence will be replaced by the video identifier.
+ - `url`: The sequence will be replaced by the video URL.
+ - `uploader`: The sequence will be replaced by the nickname of the person who uploaded the video.
+ - `upload_date`: The sequence will be replaced by the upload date in YYYYMMDD format.
+ - `title`: The sequence will be replaced by the video title.
+ext`: The sequence will be replaced by the appropriate extension (like flv or mp4).
+epoch`: The sequence will be replaced by the Unix epoch when creating the file.
+autonumber`: The sequence will be replaced by a five-digit number that will be increased with each download, starting at zero.
+
+The current default template is `%(id)s.%(ext)s`, but that will be switchted to `%(title)s-%(id)s.%(ext)s` (which can be requested with `-t` at the moment).
+
+In some cases, you don't want special characters such as 中, spaces, or &, such as when transferring the downloaded filename to a Windows system or the filename through an 8bit-unsafe channel. In these cases, add the `--restrict-filenames` flag to get a shorter title:
+
+    $ youtube-dl --get-filename -o "%(title)s.%(ext)s" BaW_jenozKc
+    youtube-dl test video ''_ä↭𝕐.mp4    # All kinds of weird characters
+    $ youtube-dl --get-filename -o "%(title)s.%(ext)s" BaW_jenozKc --restrict-filenames
+    youtube-dl_test_video_.mp4          # A simple file name
+
 # FAQ
 
 ### Can you please put the -b option back?

youtube-dl.1

@@ -139,6 +139,54 @@ You can configure youtube-dl by placing default arguments (such as
 \f[C]--extract-audio\ --no-mtime\f[] to always extract the audio and not
 copy the mtime) into \f[C]/etc/youtube-dl.conf\f[] and/or
 \f[C]~/.local/config/youtube-dl.conf\f[].
+.SH OUTPUT TEMPLATE
+.PP
+The \f[C]-o\f[] option allows users to indicate a template for the
+output file names.
+The basic usage is not to set any template arguments when downloading a
+single file, like in
+\f[C]youtube-dl\ -o\ funny_video.flv\ "http://some/video"\f[].
+However, it may contain special sequences that will be replaced when
+downloading each video.
+The special sequences have the format \f[C]%(NAME)s\f[].
+To clarify, that is a percent symbol followed by a name in parenthesis,
+followed by a lowercase S.
+Allowed names are:
+.IP \[bu] 2
+\f[C]id\f[]: The sequence will be replaced by the video identifier.
+.IP \[bu] 2
+\f[C]url\f[]: The sequence will be replaced by the video URL.
+.IP \[bu] 2
+\f[C]uploader\f[]: The sequence will be replaced by the nickname of the
+person who uploaded the video.
+.IP \[bu] 2
+\f[C]upload_date\f[]: The sequence will be replaced by the upload date
+in YYYYMMDD format.
+.IP \[bu] 2
+\f[C]title\f[]: The sequence will be replaced by the video title.
+ext\f[C]:\ The\ sequence\ will\ be\ replaced\ by\ the\ appropriate\ extension\ (like\ flv\ or\ mp4).\ epoch\f[]:
+The sequence will be replaced by the Unix epoch when creating the file.
+autonumber`: The sequence will be replaced by a five-digit number that
+will be increased with each download, starting at zero.
+.PP
+The current default template is \f[C]%(id)s.%(ext)s\f[], but that will
+be switchted to \f[C]%(title)s-%(id)s.%(ext)s\f[] (which can be
+requested with \f[C]-t\f[] at the moment).
+.PP
+In some cases, you don\[aq]t want special characters such as 中, spaces,
+or &, such as when transferring the downloaded filename to a Windows
+system or the filename through an 8bit-unsafe channel.
+In these cases, add the \f[C]--restrict-filenames\f[] flag to get a
+shorter title:
+.IP
+.nf
+\f[C]
+$\ youtube-dl\ --get-filename\ -o\ "%(title)s.%(ext)s"\ BaW_jenozKc
+youtube-dl\ test\ video\ \[aq]\[aq]_ä↭𝕐.mp4\ \ \ \ #\ All\ kinds\ of\ weird\ characters
+$\ youtube-dl\ --get-filename\ -o\ "%(title)s.%(ext)s"\ BaW_jenozKc\ --restrict-filenames
+youtube-dl_test_video_.mp4\ \ \ \ \ \ \ \ \ \ #\ A\ simple\ file\ name
+\f[]
+.fi
 .SH FAQ
 .SS Can you please put the -b option back?
 .PP