overthewire_1_12

# first of all I played with shh / scp / rsync commands
# and created a bit ugly script on perl, which expands all crap,
# I stored at structure things like
#   host_name, user_id, password or file with password
#   port, e.t.c.
#
# so, it's easy to login and trassfer files now
# if password exists, all commands gain prefix
# sshpass -p bandit0 | sshpass -f ~/tmp/bash_game/../loaded_file
# ssh user -> ssh user@server
# scp user:path -> ssh user@server:path
# scp user:'path with spaces' -> ssh user@server:"path\ with\ spaces"
#
# also port auto added if exists at config
# scp user:smth -> scp -P 2220 user@server:smth
# scp user -> scp user@path -p 2220
# rsync -R user:smth -> rsyn -e 'ssh -p 2220' --info=progress2 -R user@....
#
# script on perl
# https://pastebin.com/n7zPMMDq
#
# aliases for bash, which uses script
# https://pastebin.com/ecaU6XCm

# 0->1
cat readme
# 1->2
cat ./-
# 2->3
cat 'spaces in this filename'
# 3->4
cd inhere
ll
cat .hidden
# 4->5
cd inhere/
find . -exec file "{}" \; | grep ASCII | grep -v Non;
# 5->6
find inhere/ -readable -and -size 1033c -and ! -executable | cat

# 6->7
#1. using find options
find / -user bandit7 -group bandit6 -size 33c 2>/dev/null

# 2. find used only to iterate file
find inhere/ -type f | while read -r f; do ls -l "$f"; done | perl -awne 'print "$F[-1]\n" if ($F[0] !~ /x/ && $F[4]==1033)' | while read -r f; do file "$f"; done | grep 'ASCII text' | cut -d: -f1 | (x=$(cat);cat $x)
# explanation
#   a) ls prints giant table for each file
#   b) data from std_in read via read -r line by line
#   c) next perl oneliner works
#   perl options -awne
#   -e -- execute, perl -e 'some_code here' - common oneliner notation
#   -w -- warnings, print warnings to debug code
#   -n -  wrap code to cycle, default cycle variable $_ store line of input
#     BEGIN {some code} # optional
#     while (<>) {
#       'my code here'
#       print $_; # $_ contains result of read -r _
#     }
#     END {some code} # optional
#   -a -- autosplit by ' ', each line splited and stored at array @F
#     it's possible to user delim -F: - split via ':'
# d) use comand file on each output file via read again
# e) grep readable file
# f) get only file name part
# g) cat file, it's possible to get file_name with read -r, but I got with $(cat) for fun
#     a=$() runs anonymous shell, executes what inside and put result to variable `a`
#     cat by default reads std_in, but this time std_in is ouput from prev command
# 3. same, but via xargs versus while ... done and $(cat)
find inhere/ -type f | xargs -I {} ls -l "{}" | perl -awne 'print "$F[-1]\n" if ($F[0] !~ /x/ && $F[4]==1033)' | xargs -I {} file "{}" | grep 'ASCII text' | cut -d: -f1 | xargs cat
# explanation
# -I macro some_command arg1 "smth macro smth2" arg2..., so it's possible to use macro multiple times
# {} - notation from file -exec, but it could be any

# 7-8
grep millionth data.txt | cut -f2
# 8->9
# create struct for perl - hash a
# a = (
#   'first_str' = 3, # 3 times count
#   'second_str' = 2,
#   ...
#   'last_str' = 8,
# )
cat data.txt | perl -ne 'BEGIN{%a=();}$a{$_}++;END{while(($k,$v) = each %a) {print $k if $v==1}}'
# 9->10
cat data.txt | perl -ne 'print "$&\n" if $_ =~ /={2,}\s+\K\w{5,}/'
# want at least 2 '=' and at least 5 [a-zA-Z0-9], e.g. \w
# \K removes all matched from group
cat data.txt | grep -aPo '={2,}\s+\K(\w{5,})'
  # -a for binary files
  # -o - only matching strings
  # -P - perl regexp engine

# 10->11
base64 --decode data.txt

# 11->12
cat data.txt | perl -pe 'tr/N-ZA-Mn-za-m/A-Za-z/'
tr 'A-Za-z' 'N-ZA-Mn-za-m' < data.txt