Differences

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--- bash [2018/02/11 15:38]
+++ bash [2025/04/04 10:05] (current)
rzr [LINKS]
@@ Line 1: / Line 1: @@
+===== LEARN =====
+  * https://devhints.io/bash
+  * https://github.com/dylanaraps/pure-bash-bible
+  * https://news.ycombinator.com/item?id=25428621# MinimaL
+  * https://betterprogramming.pub/24-bashism-to-avoid-for-posix-compliant-shell-scripts-8e7c09e0f49a#
+  * https://bobcopeland.com/blog/2012/10/goto-in-bash/
+==== OneLiner ====
+  * https://github.com/onceupon/Bash-Oneliner
+  * https://ocv.me/doc/unix/oneliners/
+  for i in {0..65535} ; do printf "%x\n" $i ; done \
+  | while read -r hex ; do printf "$hex(%d): \U$hex\n" 0x$hex ; done
+==== arrays ===
+<code>
+list=(
+ "item"
+ "item with space"
+)
+for item in "${list[@]}" ; do
+  echo "$item"
+done
+</code>
+  echo 1 2 3 | { read -a words ; for value in "${words[@]}" ; do echo $value ; done }
+  end_date=($(date --date "$(date +%Y-%m-01) -1 day" "+%d %m %y"))
+  start_date=(${end_date[*]})
+  start_date[0]="01"
+  echo ${start_date} # 01
+  echo "${#start_date}" # 2
+  echo ${start_date[*]} # 01 04 20
+  echo "${#start_date[*]}" # 3
+  echo ${end_date[*]} # 30 04 20
+  echo "${start_date[@]:0:2}" # 01 04
+  * http://wiki.bash-hackers.org/syntax/arrays
+  * https://www.gnu.org/software/bash/manual/html_node/Arrays.html
+@TaG: ArraY
+==== bug ? ====
+<code>
+$SHELL --version && export LANG=C ; for i in $(seq 1 20) ; do  printf "[%d]\n" 0$i ; done 2>&1 | grep ": invalid"
+GNU bash, version 3.2.48(1)-release (i486-pc-linux-gnu)
+Copyright (C) 2007 Free Software Foundation, Inc.
+bash: printf: 08: invalid number
+bash: printf: 09: invalid number
+bash: printf: 018: invalid number
+bash: printf: 019: invalid number
+$SHELL --version && export LANG=C ; for i in $(seq 1 20) ; do  printf "[%d]\n" 0$i ; done 2>&1 | grep ": invalid"
+GNU bash, version 4.3.11(1)-release (x86_64-pc-linux-gnu)
+Copyright (C) 2013 Free Software Foundation, Inc.
+License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
+This is free software; you are free to change and redistribute it.
+There is NO WARRANTY, to the extent permitted by law.
+bash: printf: 08: invalid octal number
+bash: printf: 09: invalid octal number
+bash: printf: 018: invalid octal number
+bash: printf: 019: invalid octal number
+</code>
+Fixed in :
+  GNU bash, version 4.1.5(1)-release (i486-pc-linux-gnu)
+GNU bash, version 4.2.37(1)-release (x86_64-pc-linux-gnu)
+  bash: printf: 08: invalid octal number
+  bash: printf: 09: invalid octal number
+  printf "[%04d]\n" 9
+  [0009]
+@TaG: PrintF
+==== fork bomb ====
+  :(){:|:&};: # fork bomb
+  url=http://view.atdmt.com/action/dlXP ; while [ true ] ;do wget -O /dev/null $url ; sleep 1 ; done
+==== ${#foo} ====
+<code>
+display_string_by_packet()
+{
+    res_string=""
+    packet_len=1
+    [ "_" != "_${2}" ] && packet_len=$2
+    if [ 0 -lt ${packet_len} ] ; then
+        src_string=${1}
+        pos=${#src_string}
+        len=${packet_len}
+        while [ 0 -lt ${pos} ] ; do
+            pos=$((pos-${packet_len}))
+            if [ 0 -ge ${pos} ] ; then
+                len=$((${packet_len}+${pos}))
+                pos=0
+            fi
+            res_string=${src_string:${pos}:${len}}" "${res_string}
+        done
+    fi
+    echo -n ${res_string}
+}
+display_string_by_packet "this is a test" 2
+#| th is i s a te st
+</code>
+==== variables ====
+  echo ${foo:-bar}
+  bar
+=== $@ ===
+  echo $@ | sort | while read t ; do cat "$t" ; done > "${file}"
+https://www.gnu.org/software/bash/manual/html_node/Special-Parameters.html#index-_0040
+==== getopts ====
+  * https://www.gnu.org/software/bash/manual/html_node/Bourne-Shell-Builtins.html
+  * https://wiki-dev.bash-hackers.org/howto/getopts_tutorial#
+==== ops ====
+  * https://www.gnu.org/savannah-checkouts/gnu/bash/manual/bash.html#Here-Documents <<<
+===== env =====
+<code>
+# rzr@lap:tmp/ # [126] # mkdir  /tmp/bin/; touch /tmp/bin/script.sh
+# rzr@lap:tmp/ # [0] #  PATH="/tmp/bin:$PATH" which script.sh
+# rzr@lap:tmp/ # [1] #  PATH="/tmp/bin:$PATH" script.sh
+bash: /tmp/bin/script.sh: Permission denied
+</code>
+===== MISC =====
+  * http://wiki.bash-hackers.org/snipplets/start
+  * https://github.com/vlisivka/bash-modules
+Interactive Shell
+        if [ "${-#*i}" != "$-" ]; then
+  * http://www.tldp.org/LDP/abs/html/intandnonint.html#IITEST
+  * http://mywiki.wooledge.org/BashFAQ/002?action=diff&rev2=35&rev1=33
+  * https://github.com/tdenniston/bish# TooL CompilE
+  * https://n0where.net/bash-open-tcpudp-sockets# SockeT
+  * https://github.com/aristocratos/bashtop# CurseS
+  * https://github.com/petobens/trueline#
+  * https://betterdev.blog/minimal-safe-bash-script-template/#
+===== LINKS =====
+  * https://github.com/oils-for-unix/oils/wiki/The-Biggest-Shell-Programs-in-the-World
+  * https://github.com/lsferreira42/bash-ini-parser# ParseR
+===== MORE =====
+@TaG: [[Shell]] [[sh]] [[printf]] DeclarE
+{{http://www.monsterbashnews.com/bash/Bash2006lobbyzach.jpg}}