|
|
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Create / delete
|
Create string
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a=""
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a="abcdef"
|
abcdef
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Initialise
|
Fixed contents
|
a=""
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a="abcdef"
|
abcdef
|
|
Repeated value 'x' x 10
|
a=""
|
a=`printf %10s|tr \ x`
|
xxxxxxxxxx
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Count
|
Length of string
|
a="abc"
|
i=${#a}
|
3
|
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Length of string
|
a="abc"
|
i=`expr length $a`
|
3
|
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Size of underlying storage
|
n/a
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error
|
n/a
|
|
Number of 'X' chars in string
|
a="abcXdefXX"
|
n=`echo "$a" | tr -cd "X" | wc -c | awk '{print $1}'`
|
3
|
|
Number of 'X', 'Y' and 'Z' chars in string
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a="abcXdefYZ"
|
n=`echo "$a" | tr -cd "XYZ" | wc -c | awk '{print $1}'`
|
3
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Retrieve by index
|
Retrieve 1st char
|
a="abc"
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c=${a:0:1}
|
a
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Retrieve 1st char
|
a="abc"
|
c=`expr substr $a 1 1`
|
a
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Retrieve last char
|
a="abc"
|
c=${a:${#a}-1:1}
|
c
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Retrieve last char
|
a="abc"
|
c=`expr substr $a ${#a} 1`
|
c
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Retrieve char 'n'
|
a="abcdef"
n=2
|
c=${a:$n:1}
|
c
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Retrieve char 'n'
|
a="abcdef"
n=2
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let n1=n+1; c=`expr substr $a $n1 1`
|
c
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Slice
|
Slice from index 'm' to 'n' (inclusive)
|
a="abcdefghi"
m=3
n=6
|
s=${a:$m:$n-$m+1}
|
defg
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|
Slice from index 'n' (inclusive)
|
a="abcdefghi"
n=3
|
s=${a:$n}
|
defghi
|
|
Slice up to index 'n' (inclusive)
|
a="abcdefghi"
n=3
|
s=${a:0:$n+1}
|
abcd
|
Compare
|
Test for equality (case sensitive)
|
a="abcdef"
b="abc"
t="0"
|
if [[ "$a" == "$b" ]]; then t="1"; fi
|
0
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Test for equality (case insensitive)
|
a="abcdef"
b="ABCdef"
t="0"
|
if [[ "`echo $a | tr '[A-Z]' '[a-z]'`" == "`echo $b | tr '[A-Z]' '[a-z]'`" ]] ; then t="1" ; fi
|
1
|
|
Test for prefix
|
a="abcdef"
b="abc"
t="0"
|
if [[ `expr $a : "$b.*"` != "0" ]]; then t="1"; fi
|
1
|
|
Test for suffix
|
a="abcdef"
b="def"
|
if [[ `expr $a : ".*$b"` != "0" ]]; then t="1"; fi
|
1
|
Search
|
Test char 'is in' string
|
a="abcdefghi"
c='c'
t="0"
|
if [[ "`expr index $a $c`" != "0" ]]; then t="1"; fi
|
1
|
|
Test substring 'is in' string
|
a="abcdefghi"
b="abc"
t="0"
|
if [[ "`expr index $a $b`" != "0" ]]; then t="1"; fi
|
1
|
|
Find index of char (forward)
|
a="abcdefccccc"
c='c'
|
let i=`expr index $a $c`-1
|
2
|
|
Find index of char (reverse)
|
a="abcdefccccc"
c='c'
a=`echo $a | rev`
|
let i=${#a}-`expr index $a $c`
|
10
|
Split
|
Split on char
|
a="one,two,three"
c=','
|
ifs=$IFS; IFS=$c sa=($a); IFS=$ifs
|
one two three
|
Evaluate
|
Evaluate empty string
|
a=""
t="0"
|
if [[ "$a" ]]; then t="1"; fi
|
0
|
|
Evaluate non-empty string
|
a="abcdef"
t="0"
|
if [[ "$a" ]]; then t="1"; fi
|
1
|
Insert
|
Prepend char
|
a="bcdef"
c='a'
|
a=$c$a
|
abcdef
|
|
Append char
|
a="abc"
c='d'
|
a=$a$c
|
abcd
|
|
Insert char at index 'n'
|
a="abc"
c='X'
n=1
|
a=${a:0:$n}$c${a:$n}
|
aXbc
|
|
Prepend string
|
a="def"
b="abc"
|
a=$b$a
|
abcdef
|
|
Append string
|
a="abc"
b="def"
|
a=$a$b
|
abcdef
|
|
Insert string at index 'n'
|
a="abcghi"
b="def"
n=3
|
a=${a:0:$n}$b${a:$n}
|
abcdefghi
|
|
Concatenate 'a' and 'b'
|
a="abc"
b="def"
|
s=$a$b
|
abcdef
|
Overwrite
|
Overwrite char at index 'n'
|
a="abc"
n=1
c='B'
|
a=${a:0:$n}$c${a:$n+1}
|
aBc
|
|
Overwrite substring at index 'n'
|
a="abcdefghi"
b="DEF"
n=3
|
a=${a:0:$n}$b${a:$n +${#b}}
|
abcDEFghi
|
Replace
|
Replace 1st instance of char 'X' with 'Y'
|
a="XXXYYYZZZ"
|
a=${a/X/Y}
|
YXXYYYZZZ
|
|
Replace all instances of char 'X' with 'Y'
|
a="XXXYYYZZZ"
|
a=${a//X/Y}
|
YYYYYYZZZ
|
|
Replace 1st instance of substring 'abc' with 'XYZ'
|
a="abcdefabc"
|
a=${a/abc/XYZ}
|
XYZdefabc
|
|
Replace all instances of substring 'abc' with 'XYZ'
|
a="abcdefabc"
|
a=${a//abc/XYZ}
|
XYZdefXYZ
|
|
Replace all instances of 'X','Y','Z' with 'A','B','C' respectively
|
a="XXXYYYZZZ"
|
a=`echo $a | tr '[XYZ]' '[ABC]'`
|
AAABBBCCC
|
Remove
|
Remove 1st instance of char 'X'
|
a="XXXYYYZZZ"
|
a=${a/X}
|
XXYYYZZZ
|
|
Remove all instances of char 'X'
|
a="XXXYYYZZZ"
|
a=${a//X}
|
YYYZZZ
|
|
Remove 1st instance of substring 'abc'
|
a="abcdefabc"
|
a=${a/abc}
|
defabc
|
|
Remove all instances of substring 'abc'
|
a="abcdefabc"
|
a=${a//abc}
|
def
|
|
Remove prefix 'abc.'
|
a="abc.abc.def"
|
a=${a#abc.}
|
abc.def
|
|
Remove suffix '.def'
|
a="abc.def.def"
|
a=${a%.def}
|
abc.def
|
Remove by index
|
Remove 1st char
|
a="abcdef"
|
a=${a#?}
|
bcdef
|
|
Remove last char
|
a="abcdefghi"
|
a=${a%?}
|
abcdefgh
|
|
Remove char at index 'n'
|
a="abcdef"
n=3
|
a=${a:0:$n}${a:$n+1}
|
abcef
|
|
Remove chars in index range 'm' to 'n' (inclusive)
|
a="abcdef"
m=2
n=4
|
a=${a:0:$m}${a:$n+1}
|
abf
|
|
Remove chars from index 'n' onwards (inclusive)
|
a="abcdefghi"
n=3
|
a=${a:0:$n}
|
abc
|
|
Remove chars up to index 'n' (inclusive)
|
a="abcdefghi"
n=3
|
a=${a:$n+1}
|
efghi
|
Trim
|
Trim leading white space
|
a=" abc def "
|
a=$(echo "$a" | sed 's/^[ ]*//')
|
abc def
|
|
Trim trailing white space
|
a=" abc def "
|
a=$(echo "$a" | sed 's/[ ]*$//')
|
abc def
|
|
Trim leading and trailing white space
|
a=" abc def "
|
a=$(echo "$a" | sed 's/^[ ]*//' | sed 's/[ ]*$//')
|
abc def
|
Sort
|
Sort in ascending order
|
a="cafdeb"
|
a=`echo $a | sed -e 's/./&=/g' | tr '=' '\n' | sort | tr -d '\n'`
|
abcdef
|
|
Sort in descending order
|
a="cafdeb"
|
a=`echo $a | sed -e 's/./&=/g' | tr '=' '\n' | sort -r | tr -d '\n'`
|
fedcba
|
|
Reverse
|
a="abcdefghi"
|
a=`echo $a | rev`
|
ihgfedcba
|
Convert case
|
Convert to lower case
|
a="ABCDEFGHI"
|
a=`echo $a | tr '[A-Z]' '[a-z]'`
|
abcdefghi
|
|
Convert to upper case
|
a="abcdefghi"
|
a=`echo $a | tr '[a-z]' '[A-Z]'`
|
ABCDEFGHI
|
|
Convert first char to lower case
|
a="ABCDEFGHI"
|
a="`echo ${a:0:1} | tr '[A-Z]' '[a-z'`${a:1}"
|
aBCDEFGHI
|
|
Convert first char to upper case
|
a="abcdefghi"
|
a="`echo ${a:0:1} | tr '[a-z]' '[A-Z]'`${a:1}"
|
Abcdefghi
|
|
