fix minor details in man page

programs/zstd.1

@@ -8,7 +8,10 @@
 \fBzstd\fR [\fIOPTIONS\fR] [\-|<INPUT\-FILE>] [\-o <OUTPUT\-FILE>]
 .
 .P
-\fBunzstd\fR is equivalent to \fBzstd \-d\fR \fBzstdcat\fR is equivalent to \fBzstd \-dcf\fR
+\fBunzstd\fR is equivalent to \fBzstd \-d\fR
+.
+.P
+\fBzstdcat\fR is equivalent to \fBzstd \-dcf\fR
 .
 .SH "DESCRIPTION"
 \fBzstd\fR is a fast lossless compression algorithm and data compression tool, with command line syntax similar to \fBgzip (1)\fR and \fBxz (1)\fR\. It is based on the \fBLZ77\fR family, with further FSE & huff0 entropy stages\. \fBzstd\fR offers highly configurable compression speed, with fast modes at > 200 MB/s per code, and strong modes nearing lzma compression ratios\. It also features a very fast decoder, with speeds > 500 MB/s per core\.
@@ -22,10 +25,16 @@ Source files are preserved by default\. It\'s possible to remove them automatica
 .IP "\(bu" 4
 When compressing a single file, \fBzstd\fR displays progress notifications and result summary by default\. Use \fB\-q\fR to turn them off\.
 .
+.IP "\(bu" 4
+\fBzstd\fR does not accept input from console, but it properly accepts \fBstdin\fR when it\'s not the console\.
+.
+.IP "\(bu" 4
+\fBzstd\fR displays a short help page when command line is an error\. Use \fB\-q\fR to turn it off\.
+.
 .IP "" 0
 .
 .P
-\fBzstd\fR compresses or decompresses each \fIfile\fR according to the selected operation mode\. If no \fIfiles\fR are given or \fIfile\fR is \fB\-\fR, \fBzstd\fR reads from standard input and writes the processed data to standard output\. \fBzstd\fR will refuse to (display an error and skip the \fIfile\fR) to write compressed data to standard output if it is a terminal\. Similarly, \fBzstd\fR will refuse to read compressed data from standard input if it is a terminal\.
+\fBzstd\fR compresses or decompresses each \fIfile\fR according to the selected operation mode\. If no \fIfiles\fR are given or \fIfile\fR is \fB\-\fR, \fBzstd\fR reads from standard input and writes the processed data to standard output\. \fBzstd\fR will refuse to write compressed data to standard output if it is a terminal : it will display an error message and skip the \fIfile\fR\. Similarly, \fBzstd\fR will refuse to read compressed data from standard input if it is a terminal\.
 .
 .P
 Unless \fB\-\-stdout\fR or \fB\-o\fR is specified, \fIfiles\fR are written to a new file whose name is derived from the source \fIfile\fR name:

programs/zstd.1.md

@@ -7,8 +7,10 @@ SYNOPSIS
 `zstd` [*OPTIONS*] [-|<INPUT-FILE>] [-o <OUTPUT-FILE>]
 
 `unzstd` is equivalent to `zstd -d`
+
 `zstdcat` is equivalent to `zstd -dcf`
 
+
 DESCRIPTION
 -----------
 `zstd` is a fast lossless compression algorithm and data compression tool,
@@ -27,15 +29,19 @@ but features the following differences :
   - When compressing a single file, `zstd` displays progress notifications
     and result summary by default.
     Use `-q` to turn them off.
+  - `zstd` does not accept input from console,
+    but it properly accepts `stdin` when it's not the console.
+  - `zstd` displays a short help page when command line is an error.
+    Use `-q` to turn it off.
 
 `zstd` compresses or decompresses each _file_ according to the selected
 operation mode.
 If no _files_ are given or _file_ is `-`, `zstd` reads from standard input
 and writes the processed data to standard output.
-`zstd` will refuse to (display an error and skip the _file_) to write
-compressed data to standard output if it is a terminal.
-Similarly, `zstd` will refuse to read compressed data from standard input if it
-is a terminal.
+`zstd` will refuse to write compressed data to standard output
+if it is a terminal : it will display an error message and skip the _file_.
+Similarly, `zstd` will refuse to read compressed data from standard input
+if it is a terminal.
 
 Unless `--stdout` or `-o` is specified, _files_ are written to a new file
 whose name is derived from the source _file_ name:
@@ -162,8 +168,8 @@ Typical gains range from 10% (at 64KB) to x5 better (at <1KB).
     compressed frame header, and an ID < 65536 will only need 2 bytes.
     This compares favorably to 4 bytes default.
     However, it's up to the dictionary manager to not assign twice the same ID to
-    2 different dictionaries. 
-* `-s#`: 
+    2 different dictionaries.
+* `-s#`:
     dictionary selectivity level (default: 9)
     the smaller the value, the denser the dictionary,
     improving its efficiency but reducing its possible maximum size.
@@ -194,7 +200,7 @@ Typical gains range from 10% (at 64KB) to x5 better (at <1KB).
     Once it completes, use the value of _d_ it selects with a higher _steps_
     (in the range [256, 1024]).
 
-    `zstd --train --optimize-cover FILEs` <br /> 
+    `zstd --train --optimize-cover FILEs` <br />
     `zstd --train --optimize-cover=d=d,steps=512 FILEs`
 
 
@@ -226,7 +232,7 @@ The list of available _options_:
 - `strategy`=_strat_, `strat`=_strat_:
     Specify a strategy used by a match finder.
 
-    There are 8 strategies numbered from 0 to 7, from faster to stronger: 
+    There are 8 strategies numbered from 0 to 7, from faster to stronger:
     0=ZSTD\_fast, 1=ZSTD\_dfast, 2=ZSTD\_greedy, 3=ZSTD\_lazy,
     4=ZSTD\_lazy2, 5=ZSTD\_btlazy2, 6=ZSTD\_btopt, 7=ZSTD\_btopt2.
 

programs/zstdcli.c

@@ -167,7 +167,7 @@ static int usage_advanced(const char* programName)
 static int badusage(const char* programName)
 {
     DISPLAYLEVEL(1, "Incorrect parameters\n");
-    if (displayLevel >= 1) usage(programName);
+    if (displayLevel >= 2) usage(programName);
     return 1;
 }