Differences

This shows you the differences between two versions of the page.

--- bash_functions [2013/05/18 17:56] – [die # Exit with error code and optional message] k2patel
+++ bash_functions [2020/08/10 02:35] (current) – external edit 127.0.0.1
@@ Line 39: / Line 39: @@
 </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 ]]
+==== Trim Spaces ====
+<code bash>
+trim() #@ Trim spaces (or char in $2) from both ends of $1
+{ #@ USAGE: trim STRING [CHAR [VAR]]
+local _trim_string _trim=$1 _char=${2:- } _var=$3
+_trim_string=${_trim##*[!$_char]}
+_trim=${_trim%"$_trim_string"}
+_trim_string=${_trim%%[!$_char]*}
+_trim=${_trim#"$_trim_string"}
+is_var "$_var" &&
+printf -v "$_var" %s "$_trim" ||
+printf '%s\n' "$_trim"
+}
+</code>
+[[ https://www.linkedin.com/groups/Fridays-function-trim-Trim-spaces-3716796.S.5908643378429460481?view=&item=5908643378429460481&type=member&gid=3716796&trk=eml-b2_anet_digest-hero-1-hero-disc-disc-0&midToken=AQG8JYIVdmXjvA&fromEmail=fromEmail&ut=2lgJiLIHdb56s1 | From Article ]]