Combine -e and -n sed options - sed

I'm trying to convert all occurrences of a certain letter in the header of a file to lowercase, i can achieve this with 2 sed lines but i would like to use one instead.
What i'm trying is this:
cat file.txt | sed -e 'n 1p' -e 's/U/u/g'
Supposing that the letter i want to replace is the 'u'
I feel like i'm very close to it but for some reasons i get sed to complain about an extra char after the 'n' command, but in this case -n needs a parameter, so there should be no reason to complain.
Any hint?

This might work for you (GNU sed):
sed '1y/U/u/' file

try this (GNU sed):
sed '1s/U/u/g' file

Related

SED command to replace strings with in file

I am trying to use sed to replace strings with special characters in a text file. The sed command is becoming too much complicated. If someone could please help me with the exact command.
Code -
sed -i 's;PS1='${HOSTNAME} [$ORACLE_SID] $PWD> ';PS1="${COL_YELLOW}'CUSTOMER TEST:${HOSTNAME}:[$ORACLE_SID]:$PWD> '${COL_END}";g'
I tried to escape the special characters as below but its not working.
sed -i 's;PS1=\'\${HOSTNAME} [\$ORACLE_SID] \$PWD> \';PS1="\${COL_YELLOW}\'CUSTOMER TEST:\${HOSTNAME}:[\$ORACLE_SID]:\$PWD> \'\${COL_END}";g' .bash_profile_backup
This might work for you (GNU sed):
sed -i 's|PS1='\''${HOSTNAME} \[$ORACLE_SID\] $PWD> '\''|PS1="${COL_YELLOW}'\''CUSTOMER TEST:${HOSTNAME}:[$ORACLE_SID]:$PWD> '\''${COL_END}"|g' file
N.B. ' need to be quoted in both the pattern and replacement whereas [] needs to be escaped in the pattern only.

Sed uppercase lines if they starting with an uppercase character

I want the lines starting with one uppercase character to be uppercased, other lines should be not touched.
So this input:
cat myfile
a
b
Cc
should result in this output:
a
b
CC
I tried this command, but this not matches if i use grouping:
cat myfile | sed -r 's/\([A-Z]+.*\)/\U\1/g'
What am i doing wrong?
When you use the -r option, you must not put \ before parentheses used for grouping. So it should be:
sed -r 's/^([A-Z].*)/\U\1/' myfile
Also, notice that you need ^ to match the beginning of the line. The g modifier isn't needed, since you're matching the entire line.
cat myfile | sed 's/^\([A-Z].*\)$/\U\1/'
\U for uppercase conversion is a GNU sed extension.
Alternative for platforms where that is not available (e.g., macOS, with its BSD awk implementation):
awk '/^[A-Z]/ { print toupper($0); next } 1'
sed '/^[A-Z].*[a-z]/ s/.*/\U\1/' YourFile
only on line that are not compliant
This might work for you (GNU sed):
sed 's/^[[:upper:]].*/\U&/' file

using sed for substitution in next line

I am working on sed command to translate some text into another text.
cat text
<strong>ABC
</strong>
Commnad:
sed -e 's|<strong>(.*?)</strong>|//textbf{1}|g'
Expected Outcome: \textbf{ABC}
but using above script i cannot convert it into expected output since there is new line between the tags. How to handle such cases?
This might work for you (GNU sed):
sed -r '$!N;s|(<)(strong>)([^\n]*)\n\s*\1/\2|//textbf{\3}|;P;D' file
or
sed '$!N;s|\(<\)\(strong>\)\([^\n]*\)\n\s*\1/\2|//textbf{\3}|;P;D' file
sed -e 'N;s|<strong>\(.*\?\)\n</strong>|\/textbf{\1}|g'
as said by CodeGnome and David Ravetti, the N flag allows for multi-line patterns.

How do I get rid of this unicode character?

Any idea how to get rid of this irritating character U+0092 from a bunch of text files? I've tried all the below but it doesn't work. It's called U+0092+control from the character map
sed -i 's/\xc2\x92//' *
sed -i 's/\u0092//' *
sed -i 's///' *
Ah, I've found a way:
CHARS=$(python2 -c 'print u"\u0092".encode("utf8")')
sed 's/['"$CHARS"']//g'
But is there a direct sed method for this?
Try sed "s/\`//g" *. (I added the g so it will remove all the backticks it finds).
EDIT: It's not a backtick that OP wants to remove.
Following the solution in this question, this ought to work:
sed 's/\xc2\x92//g'
To demonstrate it does:
$ CHARS=$(python -c 'print u"asdf\u0092asdf".encode("utf8")')
$ echo $CHARS
asdf<funny glyph symbol>asdf
$ echo $CHARS | sed 's/\xc2\x92//g'
asdfasdf
Seeing as it's something you tried already, perhaps what is in your text file is not U+0092?
This might work for you (GNU sed):
echo "string containing funny character(s)" | sed -n 'l0'
This will display the string as sed sees it in octal, then use:
echo "string containing funny character(s)" | sed 's/\onnn//g'
Where nnn is the octal value, to delete it/them.

sed - substitute either of two characters with one command

I would like one sed command to accomplish the following:
$ sed s'/:/ /g' <and> sed s'/=/ /g'
That is, I would like to write
sed s'/<something>/ /g'
and have both = and : replaced by space.
sed s'/[:=]/ /g'
Brackets mean "any one of".
One option is also to use sed -e, like this. Although you don't need it in this case, it's however a good option to know about.
sed -e 's/:/ /' -e 's/..../ /' file
Sanjay's answer solves it. Another option that works with only one sed command is to separate each s substitution with a semicolon
sed 's/:/ /g ; s/=/ /g' file
or in separate lines in a script
sed 's/:/ /g
s/=/ /g' file
Those may be handy in other situations.