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--- bash_functions [2014/09/29 02:13]
k2patel [show array]
+++ bash_functions [2020/08/10 02:35]
@@ Line 1: / Line 1: @@
-====== Bash Functions ======
-==== index # Print the position of $2 in $1 ====
-<code bash>
-index() #@ Print the position of $2 in $1
-{ #@ USAGE: index STRING SUBSTRING
-local idx
-case $1 in
-*$2*) idx=${1%%$2*}
-echo $(( ${#idx} + 1 )) ;;
-*) echo 0 ;;
-esac
-}
-</code>
-[[http://www.linkedin.com/groups/Fridays-function-index-3716796.S.237745984?view=&srchtype=discussedNews&gid=3716796&item=237745984&type=member&trk=eml-anet_dig-b_pd-ttl-cn&ut=0kcr73WwfdW5I1 | From Article]]
-==== die # Exit with error code and optional message ====
-<code bash>
-die() #@ Exit with error code and optional message
-{ #@ USAGE: die RETURN_CODE [MESSAGE]
-result=$1
-shift
-[ -n "$*" ] && printf "%s\n" "$*" >&2
-exit "$result"
-}
-</code>
-[[ http://www.linkedin.com/groups/Fridays-function-die-3716796.S.236067929?qid=da8e8fcc-4fda-480a-91a1-3ef360d90e53&trk=group_most_popular_guest-0-b-ttl&goback=.gde_3716796_member_237745984.gmp_3716796 | From Article ]]
-==== Place SUBSTRING over STRING beginning at OFFSET  ====
-<code bash>
-overlay() #@ Place SUBSTRING over STRING beginning at OFFSET
-{ #@ USAGE: overlay VARNAME SUBSTRING OFFSET
-local varname=$1 substr=$2 start=$3 string
-eval "string=\${$varname}"
-left=${string:0:start}
-right=${string:start+${#substr}}
-printf -v "$varname" %s%s%s "$left" "$substr" "$right"
-}
-</code>
-[[ http://www.linkedin.com/groups/Fridays-function-overlay-3716796.S.241936021?view=&gid=3716796&type=member&item=241936021&trk=eml-anet_dig-b_nd-pst_ttle-cn | From Article ]]
-==== Print the ASCII value of the first character ====
-<code bash>
-asc() #@ Print the ASCII value of the first character of each argument
-{ #@ USAGE: asc STRING ...
-for char
-do
-printf "%d${EOV-\n}" "'$char"
-done
-}
-</code>
-[[ http://www.linkedin.com/groups/Fridays-function-asc-Print-ASCII-3716796.S.252009597?view=&gid=3716796&type=member&item=252009597&trk=eml-anet_dig-b_nd-pst_ttle-cn | From Article ]]
-==== Print argument in reverse ====
-<code bash>
-revword() #@ print each argument with bytes reversed
-for w
-do
-len=${#w}
-w2=
-n=0
-while (( ${#w2} < len ))
-do
-w2=${w:n++:1}$w2
-done
-printf "%s\n" "$w2"
-done
-</code>
-[[ http://www.linkedin.com/groups/Fridays-function-revword-3716796.S.253755071?view=&gid=3716796&type=member&item=253755071&trk=eml-anet_dig-b_nd-pst_ttle-cn | From Article ]]
-==== Add directory or directories to PATH ====
-<code bash>
-addpath() #@ add directory or directories to $PATH
-{ #@ USAGE: addpath DIR ...
-local prefix=0 quiet=0 OPTIND=1 p
-while getopts iq var
-do
-case "$var" in
-i) prefix=1 ;;
-q) quiet=1 ;;
-esac
-done
-shift $(( $OPTIND - 1 ))
-for p
-do
-p=${p%"${p##*[!/]}"} ## remove trailing slashes
-case $p in
-""|.) continue ;;
-esac
-case :$PATH: in
-*:$p:*)
-(( quiet == 0 )) && echo "addpath: $p already in path" >&2
-continue
-;;
-esac
-if [ -d "$p" ]
-then
-(( prefix == 1 )) && PATH=$p:$PATH || PATH=$PATH:$p
-else
-[ $quiet -eq 0 ] && echo "addpath: $p is not a directory" >&2
-fi
-done
-export PATH ## probably unnecessary
-}
-</code>
-[[ http://www.linkedin.com/groups/Fridays-function-addpath-Add-one-3716796.S.255801510 | From Article ]]
-==== Return random date in given range of years ====
-<code bash>
-random_date() #@ Return random date in given range of years
-{ #@ USAGE: random_date FIRST LAST [VAR]
-#@ Global variables set: random_date [VAR]
-local first=${1:-1752} last=${2:-2100} var=$3
-declare -i year month day dim
-year=$(( RANDOM % (last-first) + first ))
-month=$(( RANDOM % 12 + 1 ))
-days_in_month dim "$month" "$year"
-day=$(( RANDOM % dim + 1 ))
-printf -v random_date "%d-%02d-%02d" "$year" "$month" "$day"
-is_var "$var" &&
-printf -v "$var" %s "$random_date" ||
-printf "%s\n" "$random_date"
-}
-</code>
-[[ http://www.linkedin.com/groups/Fridays-function-randomdate-Return-random-3716796.S.5799573907065286656 | From Article ]]
-==== Check if it is factor ====
-<code bash>
-is_factor() #@ Return successfully if $2 is a factor of $1
-{ #@ USAGE: is_factor NUMBER FACTOR
-local number=$1 factor=$2
-(( ((number / factor) * factor) == number ))
-}
-</code>
-[[ http://www.linkedin.com/groups/Fridays-function-isfactor-Return-successfully-3716796.S.5794561860833390593 | From Article ]]
-==== Check if it is factor ====
-<code bash>
-dec2bin() #@ Convert decimal integer to binary optionally padding with zeroes
-{ #@ USAGE: dec2bin INT [WIDTH] [VAR]
-local val=$1 _w=$2 var=$3 _b=2 _r bin
-if (( $# == 1 )) || is_var "$2" ## is_var() posted last month
-then
-_w=1
-fi
-while ((val))
-do
-_r=$(( $val % $_b ))
-bin=$_r$bin;
-val=$(( val / _b ))
-done
-printf -v bin "%0${_w}d" "$((10#$bin))"
-is_var "$var" && printf -v "$var" %s "$bin" || printf "%s\n" "$bin"
-}
-</code>
-[[ http://www.linkedin.com/groups/Fridays-functon-dec2bin-Convert-decimal-3716796.S.277082108 | From Article ]]
-==== List running process matching args ====
-<code bash>
-psg() #@ Show all running processes matching ARG[s]
-{ #@ USAGE: psg STRING ...
-local ss
-for ss
-do
-## Enclose first character in brackets so grep doesn't show its own process
-ss=\[${ss:0:1}\]${ss#?}
-ps -ef | grep "$ss"
-[ $# -gt 1 ] && echo
-done
-}
-</code>
-[[ http://www.linkedin.com/groups/Fridays-function-psg-Show-all-3716796.S.5827514953933824001?view=&gid=3716796&type=member&item=5827514953933824001&trk=eml-anet_dig-b_nd-pst_ttle-cn | From Article ]]
-==== Print the result of arithmetical calulation ====
-<code bash>
-calc() #@ Print the result of arithmetical calulation
-{ #@ USAGE: calc EXPRESSION
-awk 'BEGIN {print '"${*//x/*}"'}'
-}
-</code>
-[[ http://www.linkedin.com/groups/Fridays-function-calc-Print-result-3716796.S.5832542139925430274?view=&srchtype=discussedNews&gid=3716796&item=5832542139925430274&type=member&trk=eml-anet_dig-b_pd-ttl-cn&fromEmail=&ut=04XvycE_RsJm41 | From Article ]]
-==== Print lines on screen descending from the current point ====
-<code bash>
-lines() #@ Print lines on screen descending from the current point
-{ #@ USAGE: [printat ROW COL [STRING];] lines STRING ...
-local cu_save=$'\e[s' cu_restore=$'\e[u' cu_down=$'\e[B'
-printf "$cu_restore$cu_down$cu_save%s" "$@"
-}
-</code>
-[[ https://www.linkedin.com/groups/Fridays-function-lines-Print-lines-3716796.S.5900869707560415236?view=&item=5900869707560415236&type=member&gid=3716796&trk=eml-b2_anet_digest-hero-1-hero-disc-disc-0&midToken=AQG8JYIVdmXjvA&fromEmail=fromEmail&ut=0fjZG80YW_UCk1 | From Article ]]
-==== Integer or Decimal ====
-<code bash>
-case ${1#-} in
-*[!0-9.]*|.) echo not an integer or float ;;
-*.*) echo float ;;
-*) echo int ;;
-esac
-</code>
-- OR -
-<code bash>
-i=$1
-let 'i++'
-if [ $? -eq 0 ] # check in not error returned
-then
-echo "integer"
-else
-echo "not integer"
-fi
-</code>
-[[ https://www.linkedin.com/groups/How-can-i-verify-if-3716796.S.5862974732210556931?view=&item=5862974732210556931&type=member&gid=3716796&trk=eml-b2_anet_digest-null-2-null&fromEmail=fromEmail&ut=3KLlfwU1D4UCk1 | From Article ]]
-==== floating point multiplication ====
-<code bash>
-fpmul() #@ Perform floating-point multiplication in the shell
-{ #@ USAGE: fpmul [VAR] NUM.DEC ...
-local _var= _places _tot _neg _n _int _dec _df _fpmul
-if [[ ${1^^} =~ ^[A-Z_][A-Z0-9_]*$ ]]
-then
-_var=$1
-shift
-fi
-_places=
-_tot=1
-_neg=
-for _n
-do
-## 2 negatives make a positive
-case $_n in
--*) [ "$_neg" = '-' ] && _neg= || _neg='-'
-_n=${_n#-}
-;;
-esac
-## Check for non-numeric characters
-case $_n in
-*[!0-9.]*) return 1 ;;
-esac
-## count the number of decimal _places,
-## then remove the decimal point
-case $_n in
-.*) _int=
-_dec=${_n#?}
-_places=$_places$_dec
-_n=$_dec
-;;
-*.*) _dec=${_n#*.}
-_int=${_n%.*}
-_places=$_places$_dec
-_n=$_int$_dec
-;;
-esac
-## remove leading zeroes
-while :
-do
-case $_n in
-""|0) _n=0
-_fpmul=0
-return
-;;
-*) _n=${_n#0} ;;
-*) break;;
-esac
-done
-## multiply by the previous _total
-_tot=$(( $_tot * ${_n:-0} ))
-## report any overflow error
-case $_tot in
--*) printf "fpmul: overflow error: %s\n" "$_tot" >&2
-return 1
-;;
-esac
-done
-while [ ${#_tot} -lt ${#_places} ]
-do
-_tot=0$_tot
-done
-_df=
-while [ ${#_df} -lt ${#_places} ]
-do
-left=${_tot%?}
-_df=${_tot#$left}$_df
-_tot=$left
-done
-_fpmul=$_tot${_df:+.$_df}
-## remove trailing zeroes or decimal points
-while :
-do
-case $_fpmul in
-*.*[0\ ]|*.) _fpmul=${_fpmul%?} ;;
-.*) _fpmul=0$_fpmul ;;
-*) break ;;
-esac
-done
-[[ $_var ]] &&
-printf -v "$_var" %s "$_fpmul" ||
-printf '%s\n' "$_fpmul"
-}
-num.dec
-</code>
-[[http://www.linkedin.com/groups/Fridays-function-fpmul-Perform-floatingpoint-3716796.S.5921339472191987716?view=&item=5921339472191987716&type=member&gid=3716796&trk=eml-b2_anet_digest-hero-1-hero-disc-disc-0&midToken=AQG8JYIVdmXjvA&fromEmail=fromEmail&ut=3_RJ7vAOch56s1|From article]]
-==== show array ====
-<code bash>
-ashow() #@ Display contents of array[s]
-{ #@ USAGE: ashow ARRAYNAME ...
-local _arg _num=0
-for arg
-do
-:; ((_num++)) && echo
-:; declare -n array=$arg
-:; [[ -n ${array[*]} ]] && printf '%s\n' "${array[@]}"
-done
-}
-</code>
-[[https://www.linkedin.com/groups/Fridays-function-ashow-Display-contents-3716796.S.5918816399794409474?view=&item=5918816399794409474&type=member&gid=3716796&trk=eml-b2_anet_digest-hero-4-hero-disc-disc-0&midToken=AQG8JYIVdmXjvA&fromEmail=fromEmail&ut=19mP4Lva0K56s1|From Article]]
-==== Reverse Word ====
-<code bash>
-revword() #@ Reverse the order of characters in STRING
-{ #@ USAGE: revword STRING [VAR]
-local _n _word=$1 _var=$2 _len _r _rw= _l
-while read -n1 _l
-do
-_rw=$_l$_rw
-done <<< "$_word"
-[[ ${_var^^} =~ ^[A-Z_][A-Z0-9_]*$ ]] &&
-printf -v "$_var" %s "$_rw" ||
-printf '%s\n' "$_rw"
-}
-</code>
-[[ https://www.linkedin.com/groups/Fridays-function-revword-Reverse-order-3716796.S.5916260779903975428?view=&item=5916260779903975428&type=member&gid=3716796&trk=eml-b2_anet_digest-hero-1-hero-disc-disc-0&midToken=AQG8JYIVdmXjvA&fromEmail=fromEmail&ut=13sqjyjg1356s1 | From Article ]]

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