bash_to_remember.md

loops

#!/bin/bash
for i in $( ls ); do
    echo item: $i
done

 #!/bin/bash
for i in $(seq 1 10);
do
    echo $i
done

#!/bin/bash 
COUNTER=0
while [  $COUNTER -lt 10 ]; do
    echo The counter is $COUNTER
    let COUNTER=COUNTER+1 
done

#!/bin/bash
COUNTER=20
until [  $COUNTER -lt 10 ]; do
    echo COUNTER $COUNTER
    let COUNTER-=1
done

rename files

for file in *.cc; do mv "$file" "$(basename "$file" .cc).cpp"; done
for file in $(find . -name *.cc); do mv "$file" "$(dirname "$file")/$(basename "$file" .cc).cpp"; done

lowercase filenames

for i in *; do mv $i `echo $i | tr [:upper:] [:lower:]`; done

Split files

# gcsplit on OSX
csplit --digits=2  --quiet --prefix=outfile infile "/-|/+1" "{*}"
csplit -n2 -s -b outfile infile "/-|/+1" "{*}"
awk '{print $0 " -|"> "file" NR}' RS='-\\|'  input-file

Operate on each line of file

for i in $(cat tmp.txt);  do touch $i; done

# may need to set IFS first to $'\n'

Find symbol in dylibs

for i in $(ls *.dylib); do
    echo "$i"; nm -g $i | grep <text>
done