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--- maths [2015/05/09 21:15] – created luke7858
+++ maths [2024/05/23 07:26] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
-You can use bc in bash to do math calculations with decimals.
+=== bc ===
-\\
+You can use bc in bash to do maths calculations with decimals. The man pages can be found:
 <sxh bash>
 http://unixhelp.ed.ac.uk/CGI/man-cgi?bc+1
 </sxh>
 \\
+== Example Calulation ==
 <sxh bash>
 bc -l <<< "20 / ( 20 + 80) * 100 "
@@ Line 12: / Line 13: @@
 .00000000000000000000
 </sxh>
+<sxh bash>
+-l = --mathlib = Defines the standard math library
+</sxh>
+\\
+=== Limiting the decimal place ===
 You can then use this with printf to limit the number of decimals shown:
 \\The example below shows the results to 3 decimal places. You can replace the 3 with what ever value you wish to place
@@ Line 21: / Line 27: @@
 <sxh bash>
 bc -l <<< "($used / ( $free + $used) ) * 100 ")
+</sxh>
+\\
+=== Comparing Decimals with bc ===
+You are able to compare decimal numbers using bc. The output will return 1 or 0 depending on the results. You can then use this with an if statment -le / -ge etc
+<sxh bash>
+.4 '<' 1.3 | bc -l
+</sxh>
+\\
+<sxh bash>
+example= $(echo 1.4 '<' 1.3 | bc -l)
+if [ $example-eq 0 ]; then
+elif [ $example-eq 1  ]; then
+fi
 </sxh>