Edit bash_manip-3-grep.md

docs/pages/bash_manip/bash_manip-3-grep.md

@@ -24,7 +24,7 @@ It has a lot of options but the most common ones are:
 | -v | Invert the match, showing lines that do not match the pattern. |
 | -n | Prefix each line of output with the line number. |
 | -c | Print only a count of matching lines per file. |
-| -o | Print each match on a new line. |
+| -o | Print each match on a new line.  (/!\ not copatible with -c)|
 
 ## Excercice
 
@@ -44,6 +44,7 @@ It has a lot of options but the most common ones are:
     # -o makes grep print each match on a new line.
     # wc -l counts the number of lines, which equals the total occurrences
     # 871258
+    # /!\ not copatible with -c
     ```
 
 !!! question "Select all line related of the year 2001 in `nat2021.csv` file"