Script on bash, can you? - linux

There is a string $STRING, in which syllables are written with the spaces. If the variable $WORD have at least one syllable in this string, report of this in any way.

Your solution checks to see if $WORD exists in $STRING when it should be the other way around. Try this:
string="run walk stand"
word=walking
if echo "$string" | sed -e 's/ /\n/g' | grep -Fqif - <(echo "$word")
then
echo "Match!"
fi
As you can see, you can test the result of the grep without having to save the output in a variable.
By the way -n is the same as ! -z.

Related

What is the proper way to convert first character of a string from upper to lower case in shell scripting on Mac OS? [duplicate]

I want to uppercase just the first character in my string with bash.
foo="bar";
//uppercase first character
echo $foo;
should print "Bar";
One way with bash (version 4+):
foo=bar
echo "${foo^}"
prints:
Bar
foo="$(tr '[:lower:]' '[:upper:]' <<< ${foo:0:1})${foo:1}"
One way with sed:
echo "$(echo "$foo" | sed 's/.*/\u&/')"
Prints:
Bar
$ foo="bar";
$ foo=`echo ${foo:0:1} | tr '[a-z]' '[A-Z]'`${foo:1}
$ echo $foo
Bar
To capitalize first word only:
foo='one two three'
foo="${foo^}"
echo $foo
One two three
To capitalize every word in the variable:
foo="one two three"
foo=( $foo ) # without quotes
foo="${foo[#]^}"
echo $foo
One Two Three
(works in bash 4+)
Using awk only
foo="uNcapItalizedstrIng"
echo $foo | awk '{print toupper(substr($0,0,1))tolower(substr($0,2))}'
Here is the "native" text tools way:
#!/bin/bash
string="abcd"
first=`echo $string|cut -c1|tr [a-z] [A-Z]`
second=`echo $string|cut -c2-`
echo $first$second
just for fun here you are :
foo="bar";
echo $foo | awk '{$1=toupper(substr($1,0,1))substr($1,2)}1'
# or
echo ${foo^}
# or
echo $foo | head -c 1 | tr [a-z] [A-Z]; echo $foo | tail -c +2
# or
echo ${foo:1} | sed -e 's/^./\B&/'
It can be done in pure bash with bash-3.2 as well:
# First, get the first character.
fl=${foo:0:1}
# Safety check: it must be a letter :).
if [[ ${fl} == [a-z] ]]; then
# Now, obtain its octal value using printf (builtin).
ord=$(printf '%o' "'${fl}")
# Fun fact: [a-z] maps onto 0141..0172. [A-Z] is 0101..0132.
# We can use decimal '- 40' to get the expected result!
ord=$(( ord - 40 ))
# Finally, map the new value back to a character.
fl=$(printf '%b' '\'${ord})
fi
echo "${fl}${foo:1}"
This works too...
FooBar=baz
echo ${FooBar^^${FooBar:0:1}}
=> Baz
FooBar=baz
echo ${FooBar^^${FooBar:1:1}}
=> bAz
FooBar=baz
echo ${FooBar^^${FooBar:2:2}}
=> baZ
And so on.
Sources:
Bash Manual: Shell Parameter Expansion
Full Bash Guide: Parameters
Bash Hacker's Wiki Parameter Expansion
Inroductions/Tutorials:
Cyberciti.biz: 8. Convert to upper to lower case or vice versa
Opensource.com: An introduction to parameter expansion in Bash
This one worked for me:
Searching for all *php file in the current directory , and replace the first character of each filename to capital letter:
e.g: test.php => Test.php
for f in *php ; do mv "$f" "$(\sed 's/.*/\u&/' <<< "$f")" ; done
Alternative and clean solution for both Linux and OSX, it can also be used with bash variables
python -c "print(\"abc\".capitalize())"
returns Abc
This is POSIX sh-compatible as far as I know.
upper_first.sh:
#!/bin/sh
printf "$1" | cut -c1 -z | tr -d '\0' | tr [:lower:] [:upper:]
printf "$1" | cut -c2-
cut -c1 -z ends the first string with \0 instead of \n. It gets removed with tr -d '\0'. It also works to omit the -z and use tr -d '\n' instead, but this breaks if the first character of the string is a newline.
Usage:
$ upper_first.sh foo
Foo
$
In a function:
#!/bin/sh
function upper_first ()
{
printf "$1" | cut -c1 -z | tr -d '\0' | tr [:lower:] [:upper:]
printf "$1" | cut -c2-
}
old="foo"
new="$(upper_first "$old")"
echo "$new"
Posix compliant and with less sub-processes:
v="foo[Bar]"
printf "%s" "${v%"${v#?}"}" | tr '[:lower:]' '[:upper:]' && printf "%s" "${v#?}"
==> Foo[Bar]
first-letter-to-lower () {
str=""
space=" "
for i in $#
do
if [ -z $(echo $i | grep "the\|of\|with" ) ]
then
str=$str"$(echo ${i:0:1} | tr '[A-Z]' '[a-z]')${i:1}$space"
else
str=$str${i}$space
fi
done
echo $str
}
first-letter-to-upper-xc () {
v-first-letter-to-upper | xclip -selection clipboard
}
first-letter-to-upper () {
str=""
space=" "
for i in $#
do
if [ -z $(echo $i | grep "the\|of\|with" ) ]
then
str=$str"$(echo ${i:0:1} | tr '[a-z]' '[A-Z]')${i:1}$space"
else
str=$str${i}$space
fi
done
echo $str
}
first-letter-to-lower-xc(){
v-first-letter-to-lower | xclip -selection clipboard
}
Not exactly what asked but quite helpful
declare -u foo #When the variable is assigned a value, all lower-case characters are converted to upper-case.
foo=bar
echo $foo
BAR
And the opposite
declare -l foo #When the variable is assigned a value, all upper-case characters are converted to lower-case.
foo=BAR
echo $foo
bar
What if the first character is not a letter (but a tab, a space, and a escaped double quote)? We'd better test it until we find a letter! So:
S=' \"ó foo bar\"'
N=0
until [[ ${S:$N:1} =~ [[:alpha:]] ]]; do N=$[$N+1]; done
#F=`echo ${S:$N:1} | tr [:lower:] [:upper:]`
#F=`echo ${S:$N:1} | sed -E -e 's/./\u&/'` #other option
F=`echo ${S:$N:1}
F=`echo ${F} #pure Bash solution to "upper"
echo "$F"${S:(($N+1))} #without garbage
echo '='${S:0:(($N))}"$F"${S:(($N+1))}'=' #garbage preserved
Foo bar
= \"Foo bar=

Bash- scramble characters contained in a string

So I have this function with the following output:
AGsg4SKKs74s62#
I need to find a way to scramble the characters without deleting anything..aka all characters must be present after I scramble them.
I can only bash utilities including awk and sed.
echo 'AGsg4SKKs74s62#' | sed 's/./&\n/g' | shuf | tr -d "\n"
Output (e.g.):
S7s64#2gKAGsKs4
Here's a pure Bash function that does the job:
scramble() {
# $1: string to scramble
# return in variable scramble_ret
local a=$1 i
scramble_ret=
while((${#a})); do
((i=RANDOM%${#a}))
scramble_ret+=${a:i:1}
a=${a::i}${a:i+1}
done
}
See if it works:
$ scramble 'AGsg4SKKs74s62#'
$ echo "$scramble_ret"
G4s6s#2As74SgKK
Looks all right.
I know that you haven't mentioned Perl but it could be done like this:
perl -MList::Util=shuffle -F'' -lane 'print shuffle #F' <<<"AGsg4SKKs74s62#"
-a enables auto-split mode and -F'' sets the field separator to an empty string, so each character goes into a separate array element. The array is shuffled using the function provided by the core module List::Util.
Here is my solution, usage: shuffleString "any-string". Performance is not in my consideration when using bash.
function shuffleString() {
local line="$1"
for i in $(seq 1 ${#line}); do
local p=$(expr $RANDOM % ${#line})
if [[ $p -lt $i ]]; then
local line="${line:0:$p}${line:$i:1}${line:$p+1:$i-$p-1}${line:$p:1}${line:$i+1}"
elif [[ $p -gt $i ]]; then
local line="${line:0:$i}${line:$p:1}${line:$i+1:$p-$i-1}${line:$i:1}${line:$p+1}"
fi
done
echo "$line"
}

Command to count the characters present in the variable

I am trying to count the number of characters present in the variable. I used the below shell command. But I am getting error - command not found in line 4
#!/bin/bash
for i in one; do
n = $i | wc -c
echo $n
done
Can someone help me in this?
In bash you can just write ${#string}, which will return the length of the variable string, i.e. the number of characters in it.
Something like this:
#!/bin/bash
for i in one; do
n=$(echo $i | wc -c)
echo $n
done
Assignments in bash cannot have a space before the equals sign. In addition, you want to capture the output of the command you run and assign that to $n, rather than that statement which would probably just assign $i to $n.
Use the following instead:
#!/bin/bash
for i in one; do
n=`$i | wc -c`
echo $n
done
It can be as simple as that:
str="abcdef"; wc -c <<< "$str"
7
But mind you that end of line counts as a character:
str="abcdef"; cat -A <<< "$str"
abcdef$
If you need to remove it:
str="abcdef"; tr -d '\n' <<< "$str" | wc -c
6

How to extract a part of string?

I have string contains a path
string="toto.titi.1.tata.2.abc.def"
I want to extract the substring which is situated after toto.titi.1.tata.2.. but 1 and 2 here are examples and could be other numbers.
In general: I want to extract the substring which situated after toto.titi.[i].tata.[j]..
[i] and [j] are a numbers
How to do it?
Pure bash solution:
[[ $string =~ toto\.titi\.[0-9]+\.tata\.[0-9]+\.(.*$) ]] && result="${BASH_REMATCH[1]}"
echo "$result"
An alternate bash solution that uses parameter expansion instead of a regular expression:
echo "${string#toto.titi.[0-9].tata.[0-9].}"
If the numbers can be multi-digit values (i.e., greater than 9), you would need to use an extended pattern:
shopt -s extglob
echo "${string#toto.titi.+([0-9]).tata.+([0-9]).}"
You can use cut
echo $string | cut -f6- -d'.'
This does it:
echo ${string} | sed -re 's/^toto\.titi\.[[:digit:]]+\.tata\.[[:digit:]]+\.//'
May be like this:
echo "$string" | cut -d '.' -f 6-
You can use sed. Like this:
string="toto.titi.1.tata.2.abc.def"
string=$(sed 's/toto\.titi\.[0-9]\.tata\.[0-9]\.//' <<< "$string")
echo "$string"
Output:
abc.def
try this awk line:
awk -F'toto\\.titi\\.[0-9]+\\.tata\\.[0-9]+\\.' '{print $2}' file
with your example:
kent$ echo "toto.titi.1.tata.2.abc.def"|awk -F'toto\\.titi\\.[0-9]+\\.tata\\.[0-9]+\\.' '{print $2}'
abc.def

linux shell title case

I am wrinting a shell script and have a variable like this: something-that-is-hyphenated.
I need to use it in various points in the script as:
something-that-is-hyphenated, somethingthatishyphenated, SomethingThatIsHyphenated
I have managed to change it to somethingthatishyphenated by stripping out - using sed "s/-//g".
I am sure there is a simpler way, and also, need to know how to get the camel cased version.
Edit: Working function derived from #Michał's answer
function hyphenToCamel {
tr '-' '\n' | awk '{printf "%s%s", toupper(substr($0,1,1)), substr($0,2)}'
}
CAMEL=$(echo something-that-is-hyphenated | hyphenToCamel)
echo $CAMEL
Edit: Finally, a sed one liner thanks to #glenn
echo a-hyphenated-string | sed -E "s/(^|-)([a-z])/\u\2/g"
a GNU sed one-liner
echo something-that-is-hyphenated |
sed -e 's/-\([a-z]\)/\u\1/g' -e 's/^[a-z]/\u&/'
\u in the replacement string is documented in the sed manual.
Pure bashism:
var0=something-that-is-hyphenated
var1=(${var0//-/ })
var2=${var1[*]^}
var3=${var2// /}
echo $var3
SomethingThatIsHyphenated
Line 1 is trivial.
Line 2 is the bashism for replaceAll or 's/-/ /g', wrapped in parens, to build an array.
Line 3 uses ${foo^}, which means uppercase (while ${foo,} would mean 'lowercase' [note, how ^ points up while , points down]) but to operate on every first letter of a word, we address the whole array with ${foo[*]} (or ${foo[#]}, if you would prefer that).
Line 4 is again a replace-all: blank with nothing.
Line 5 is trivial again.
You can define a function:
hypenToCamel() {
tr '-' '\n' | awk '{printf "%s%s", toupper(substr($0,0,1)), substr($0,2)}'
}
CAMEL=$(echo something-that-is-hyphenated | hypenToCamel)
echo $CAMEL
In the shell you are stuck with being messy:
aa="aaa-aaa-bbb-bbb"
echo " $aa" | sed -e 's/--*/ /g' -e 's/ a/A/g' -e 's/ b/B/g' ... -e 's/ *//g'
Note the carefully placed space in the echo and the double space in the last -e.
I leave it as an exercise to complete the code.
In perl it is a bit easier as a one-line shell command:
perl -e 'print map{ $a = ucfirst; $a =~ s/ +//g; $a} split( /-+/, $ARGV[0] ), "\n"' $aa
For the records, here's a pure Bash safe method (that is not subject to pathname expansion)—using Bash≥4:
var0=something-that-is-hyphenated
IFS=- read -r -d '' -a var1 < <(printf '%s\0' "${var0,,}")
printf '%s' "${var1[#]^}"
This (safely) splits the lowercase expansion of var0 at the hyphens, with each split part in array var1. Then we use the ^ parameter expansion to uppercase the first character of the fields of this array, and concatenate them.
If your variable may also contain spaces and you want to act on them too, change IFS=- into IFS='- '.

Resources