I am trying to find the following text
get_pins {
and replace it with
get_pins -hierarchical {proc_top_*/
I've tried using sed but I'm not sure what I'm doing wrong. I know that you need # in front of curly braces but I still can't get the command to work properly.
The closest I've come is to this:
sed 's/get_pins #{#/get_pins -hierarchical #{#proc_top_*\//g' filename.txt > output
but it doesn't do the replacement I wanted above.
#merlin2011's answer shows you how to do it with alternative delimiters, but as for why your command didn't work:
It's actually perfectly fine, if you just remove all # chars. from your statement:
sed 's/get_pins {/get_pins -hierarchical {proc_top_*\//'g filename.txt > output
There are two distinct escaping requirements involved here:
Escaping literal use of the regex delimiter: this is what you did correctly, by escaping the / as \/.
Escaping characters with special meaning inside a regex in general: this escaping is always done with \-prefixing, but in your case there is NO need for such escaping: since you're NOT using -E or -r to indicate use of extended regexes - and are therefore using a basic regex - { is actually NOT a special character, so you need NOT escape it. If, by contrast, you had used -E (-r), then you should have escaped { as \{.
The problem is not in the curly braces, it's in the /.
This is exactly why sed lets you do alternate delimiters.
The line below uses ! as a delimiter instead, and works correctly for a simple file with get_pins { in it.
sed 's!get_pins {!get_pins -hierarchical {proc_top_*/!g' Input.txt
Output:
get_pins -hierarchical {proc_top_*/
Update: Based mklement0's comment, and testing with the csh shell, the following should work in csh.
sed 's#get_pins {#get_pins -hierarchical {proc_top_*/#g' Input.txt
This awk should do the replace:
awk '{sub(/get_pins {/,"get_pins -hierarchical {proc_top_*/")}1'
Related
I'm trying to search in all files a text, and replace it with the word EXAMPLE. I do the following:
for f in /home/testu/zz*; do
sed -i "s/&VAR1\s*=\s*'?[1]{4}'?/EXAMPLE/g" "$f"
done
It gives no error, the files seems to be "updated" in the filesystem, but they wont get changed. If I test that regexp with the grep command it works fine, so something must be wrong with SED, could it be SED version?
Thanks in advance.
Your current sed command parses the regular expression as a POSIX BRE compliant pattern.
In BRE POSIX, ? matches a literal ? char, and { / } also match literal { / } chars. To make a range quantifier in a BRE POSIX pattern, you need to escape {...}, \{min,max\}.
The [1] is equal to 1, so the brackets are quite redundant here.
To fix your pattern, you may replace ? with \{0,1\} (0 or 1 occurrences) and {4} with \{4\}:
sed -i "s/&VAR1\s*=\s*'\{0,1\}1\{4\}'\{0,1\}/EXAMPLE/g" "$f"
Thanks to Wiktor Stribiżew tips, we got the solution (SSED GNU 4.1.5). The resulting regexp works with grep and sed. The code was a mix of solutions at the end.
sed -i "s/&VAR1\s*=\s*'\{0,\}1\{4\}'\{0,\};\{0,\}/EXAMPLE/g" "$f"
A few things:
Things like [[:blank:]] caused error of input file.
My sed version didnt support -E, so the {} had to be escaped, didn't know that :)
Thanks again Wiktor!
I'm trying to replace a every reference of \' with ' in a file
I've used variations of: sed -e s/\'/"\'"/g file.txt
But they always replace every.single.(single).quote
Any help would be greatly appreciated.
Not sure it's the best solution,I could do it like this:
sed "s/[\]'/\"\'\"/g" file.txt
(putting the backslash character in a character range so it doesn't interfere with the following quote, and protect with double quotes)
Or just extending your syntax, without quotes but using almost the same trick:
sed -e s/[\\]\'/"\'"/g file.txt
An approach trying to conserve as much of the "single-quotedness" of the sed command as possible:
sed 's/\\'"'"'/\'/g'
Just escaping \ with \\ and getting a single quote into the command with '"'"': the first single quote ends the command so far, then we have a double-quoted single quote ("'"), and finally an opening single quote for the rest of the command.
Alternatively, double quoting the whole command and escaping both the backslash and single quote:
sed "s/\\\'/\'/g"
The correct syntax is:
$ echo "foo'bar" | sed 's/'\''/\'/'
foo'bar
Every script (sed, awk, whatever) should always be enclosed in single quotes and you just us other single quotes to stop/restart the script delimiters break out to shell for the minimal portion of the script that's absolutely necessary, in this case long enough to use \'. You need to break out to shell to specify that ' because per shell rules no script enclosed in 's can contain a ', not even if you try to escape it.
echo "foo'bar" | gawk '{gsub(/\47/,"\\'")}1'
foo'bar
The tricky part here is to replace a single quote with ampersand.
First in order to make the single quote manageable use its octal
code here \47 and then escaping ampersand by two back slash. And all of sudden
it becomes feasible :)
New to sed, so please bear with me...
I have a php file which contains the following line:
define('TARGET_A','044');
Id like to find that line and replace it with the following using sed:
define('TARGET_K','076');
I have tried:
$ sed -i 's/define\(\'TARGET_A\',\'044\'\)\;/define\(\'TARGET_K\',\'076\'\)\;/' myfile.php
I have tried SEVERAL variations, tried escaping the parens and removing the semicolon, nothing seems to work
ANY help at all GREATLY appreciated, thanks
That's a lot of escaping. How about... no escaping at all?
sed -i '.bak' "s/define('TARGET_A','044');/define('TARGET_K','076');/" myfile.php
Example:
cternus#astarael:~⟫ cat myfile.php
define('TARGET_A','044');
cternus#astarael:~⟫ sed -i '.bak' "s/define('TARGET_A','044');/define('TARGET_K','076');/" myfile.php
cternus#astarael:~⟫ cat myfile.php
define('TARGET_K','076');
This worked for me:
$sed -i "s/define('TARGET_A','044');/define('TARGET_K','076');/" myfile.php
I changed the argument string delimiter to make it simpler.
You can't escape 's in a '-delimited script so you need to escape back to shell with '\'' whenever you need a '. You might be tempted to use " to delimit the script instead but then you're opening it up to shell variable expansion, etc. so you need to be careful about what goes in your script and escape some characters to stop the shell from expanding them. It's much more robust (and generally makes your scripts simpler) to just stick to single quotes and escape back to shell just for the parts you NEED to:
$ sed 's/define('\''TARGET_A'\'','\''044'\'');/define('\''TARGET_K'\'','\''076'\'');/' file
define('TARGET_K','076');
I know about s// type command in sed, however never saw using s#. Could someone explain what exactly this is doing?
% sed -e "s#SRC_DIR=.*#SRC_DIR=$PROJECT_SRC_DIR#g" -i proj.cfg
I understand that -e defines a script to execute, and the script is withing "", but what exactly s# does?
Checked http://www.grymoire.com/Unix/Sed.html and gnu website, but no luck.
# is a sed delimiter like /. We could use ~, #, /, ;, etc as sed delimiters. They uses a different delimiter # because they don't want to escape / slashes. If you use # as delimiter, you don't need to escape / forward slash. But if you use / as delimiter, you must need to escape / as \/ or otherwise sed would consider / as delimiter.
From sed's manual:
The syntax of the s (as in substitute) command is ‘s/regexp/replacement/flags’. The / characters may be uniformly replaced by any other single character within any given s command. The / character (or whatever other character is used in its stead) can appear in the regexp or replacement only if it is preceded by a \ character.
I wan't to replace a string like Europe12 with Europe12_yesturday in a file. Without changing the Europe12-36 strings that also exists in the file.
I tried:
$basename=Europe12
sed -i 's/\b$basename\b/${basename}_yesterday/g' file.txt
but this also changed the Europe12-36 strings.
Require a space or end of line character:
sed 's/Europe12\([ ]|$\)/Europe12_yesturday\1/g' input
Manually construct the delimiter list you want instead of using \b, \W or \<. - is not part of the word characters (alphanumericals), so that's why this also matches your other string. So try something like this, expanding the list as needed: [-a-zA-Z0-9].
You can do it in 2 times:
sed -e 's/Europe12/Europe12_yesturday/g' -e 's/Europe12_yesturday-36/Europe12-36/g' file.txt
sed 's/\(Europe12[[:blank:]]\)/\1_yesturday/g;s/Europe12$/&_yesturday/' YourFile
[[:blank:]] could be completeted with any boundary you accept also like .,;:/]) etc (be carrefull of regex meaning of this char in this case)
It is little late to reply..
It can be achieved easily by "word boundary" notation (\<..\>)
sed -i 's/\<$basename\>/${basename}_yesterday/g' file.txt