stupid human tricks

So, my memories shot to hell and back and some things are next to impossible to hold in there. Of course, bash scripting requires memorization 🙂
So, I slapped together a quick “cheat sheet” that pretty much is what I remembered before but can’t now (easily). I keep it as a quick go-to at my desk. Figured I’d share.

for loop syntax

for VARIABLE in 1 2 3 4 5 .. N do command1 command2 commandN done	for i in 1 2 3 4 5 do echo “Welcome $i times” done
for i in $(seq 1 2 20) do echo “Welcome $i times” done	for i in {1..5} do echo “Welcome $i times” done
for (( EXP1; EXP2; EXP3 )) do command1 command2 command3 done	for (( EXP1; EXP2; EXP3 )) do command1 command2 command3 done
for (( EXP1; EXP2; EXP3 )) do command1 command2 command3 done	for (( EXP1; EXP2; EXP3 )) do command1 command2 command3 done
for (( EXP1; EXP2; EXP3 )) do command1 command2 command3 done	for (( c=1; c<=5; c++ )) do echo “Welcome $c times…” done
for (( ; ; )) do echo “infinite loops [ hit CTRL+C to stop]” done	for I in 1 2 3 4 5 done statements1      #Executed for all values of ”I”, up to a disaster-condition if any. statements2 if (disaster-condition) then break #Abandon the loop. fi statements3     #While good and, no disaster-condition. done
#!/bin/bash for file in /etc/* do if [ “${file}” == “/etc/resolv.conf” ] then countNameservers=$(grep -c nameserver /etc/resolv.conf) echo “Total  ${countNameservers} nameservers defined in ${file}” break fi done
for I in 1 2 3 4 5 done statements1      #Executed for all values of ”I”, up to a disaster-condition if any. statements2 if (condition) then continue #Go to next iteration of I in the loop and skip statements3 fi statements3 done	FILES=”$@” for f in $FILES do if [ -f ${f}.bak ] then echo “Skiping $f file…” continue fi /bin/cp $f $f.bak done