This is my current code. I am trying to replace a filename string in the file with another filename. But I am currently getting the error
"sed: 1: "s/directory = "[A-Za-z0 ...": bad flag in substitute command: 'U'"
What is wrong with this code?
function restart_existing ()
{
old="directory = \"[A-Za-z0-9\/]\""
new="directory = \"$1\""
sed -i '' "s/$old/$new/" "$HOME/angelpretendconfig"
}
restart_existing "$HOME/blahblahblah/shoot/blah"
EDIT:
Thanks! I've adopted your advice, and adapted the code.
function restart_existing ()
{
old="directory = \"*\""
printf -v new 'directory = "%s"' "$1"
sed -i '' "s;$old;$new;" "$HOME/angelpretendconfig"
}
restart_existing "Query"
But now the line in question goes from
directory = "/home/jamie/bump/server"
directory = "Query"/home/jamie/bump/server"
Why does this occur?
Don't use forward slashes in sed when what you're replacing contains forward slashes:
$ sed 's;foo/bar;baz/wuz;' <<< "where is the foo/bar?"
where is the baz/wuz?
Also, sometimes it's more readable to avoid manually escaping quotes:
function restart_existing ()
{
old='directory = "[A-Za-z0-9\/]"'
printf -v new 'directory = "%s"' "$1"
sed -i '' "s;$old;$new;" "$HOME/angelpretendconfig"
}
restart_existing "$HOME/blahblahblah/shoot/blah"
$1 contains something, which is parsed as a special command to sed, in this case probably a / which marks the end of the replacement string, followed by some other characters.
You have to escape the replacement string first: Escape a string for a sed replace pattern.
Related
I'm trying to add a line in a file afile.xyz using my script. This is what I've done so far using sed:
n="$(grep ".method" "$m" | grep "onCreate(Landroid/os/Bundle;)V")"
sed -i '' -e '/$n/ a\
"test", /Users/username/Documents/afile.xyz
I'm getting the error:
"onCreate\(\Landroid\/ ...": bad flag in substitute command: 'g'
How do I solve this? Please do help. Thanks.
Edit: Content of n
method protected onCreate(Landroid/os/Bundle;)V
2 problems:
because the sed body is in single quotes, the variable $n will not be expanded,
the regular expression in $n contains the / dilimiters.
Try this:
n=$(...)
nn=${n//\//\\/} # escape all slashes
sed -i '' '/'"${nn}"'/ a ...
The single-quoted sed body is interrupted to append the double quoted shell variable.
You can also use a different delimiter for the RE:
sed -i '' -e "\#$n# a\\
\"test\"" /Users/username/Documents/afile.xyz
I'm trying to use a variable in a sed append and hitting an issue.
The following command works as expected:
sed -i "\:#file = /mnt/var/log/hadoop-yarn/containers/application_1495965866386_0001/container_1495965866386_0001_01_000002/stderr:a file = /path/to/other/file" /etc/conf/service.conf
However if I replace the pattern with a variable I'm hitting an error:
$ echo $item
#file = /mnt/var/log/hadoop-yarn/containers/application_1495965866386_0001/container_1495965866386_0001_01_000002/stdout
$ sed -i "\:$item:a file = /path/to/other/file" /etc/conf/service.conf
sed: -e expression #1, char 122: unterminated address regex
EDIT for more info: So the 'item' variable is being populated from an array. That array is created from a readarray and grep:
$readarray LINES < <(grep "#file = /mnt/var/" /etc/conf/service.conf)
$item=${LINES[1]}
$echo $item
#file = /mnt/var/log/hadoop-yarn/containers/application_1495965866386_0001/container_1495965866386_0001_01_000002/stdout
However I've found if i populate 'item' manually it then works e.g:
$item="#file = /mnt/var/log/hadoop-yarn/containers/application_1495965866386_0001/container_1495965866386_0001_01_000002/stdout"
$sed -i "\:$item:a file = /path/to/other/file" /etc/conf/service.conf
$
So something strange seems to be happening with the readarray/grep
So the problem here turned out to be newline characters that were being pulled in as part of the grep.
This is why populating $item manually worked - no '\n'
Thanks to Ed Morton for pointing me in the right direction. While
echo "$item" | cat -v
did not show anything I added '-t' to the readarray command to trim newline characters:
$readarray -t LINES < <(grep "#file = /mnt/var/" /etc/conf/service.conf)
After that things worked as expected.
I have a string in which I need to replace "," with "\," using shell script. I thought I can use sed to do this but no luck.
You can do that without sed:
string="${string/,/\\,}"
To replace all occurrences of "," use this:
string="${string//,/\\,}"
Example:
#!/bin/bash
string="Hello,World"
string="${string/,/\\,}"
echo "$string"
Output:
Hello\,World
You need to escape the back slash \/
I'm not sure what your input is but this will work:
echo "teste,test" |sed 's/,/\\/g'
output:
teste\test
Demo:
http://ideone.com/JUTp1X
If the string is on a file, you can use:
sed -i 's/,/\//g' myfile.txt
I'm trying to use sed to change a variable in the site.js file on my server.
Here is the line: var url = "page.php"; I'm looking to just substitute page.php for whatever.php.
I thought this would be pretty simple and I figured this would work with no issues:
sed -i "s/\url = \".*\"/\url = \"page2.php\"/" /home/site.js
It works okay except instead of getting: var url = "page2.php"; I get: var R1 = "page2.php";
Why is the url value being changed to R1 when I use sed here?
You don't need \ before url.
sed -i -r 's#url\s*=\s*"[^"]+"#url = "page2.php"#' /home/site.js
Extra escaping of " can be eliminated by enclosing sed expression with ' instead of "
It's better to use different separator than / (here #) when the strings themselves may contain /
Try doing this :
sed -i -r 's#(var\s+url\s*=\s*")[^"]+"#\1whatever.php"#' file.js
/ is not mandatory as delimiter, I've picked up # there.
Here's another example: Took me while to figure that you change the / for delimiter and not the / in the directory path.
Use # instead of / for sed delimiter if you have dir path names.
First I tried this:
[root#ip-172-35-24-37 ec2-user]# egrep -q "^(\s*\S+\s+)/dev/shm(\s+\S+\s+\S+)(\s+\S+\s+\S+)(\s*#.*)?\s*$" /etc/fstab && sed -ri "s/^(\s*\S+\s+)/dev/shm(\s+\S+\s+\S+)(\s+\S+\s+\S+)(\s*#.*)?\s*$/\1/dev/shm\2nodev\3\4/" /etc/fstab
And got this error:
sed: -e expression #1, char 20: unknown option to `s'
So then I used # for the sed delimiter instead of /:
[root#ip-172-35-24-37 ec2-user]# egrep -q "^(\s*\S+\s+)/dev/shm(\s+\S+\s+\S+)(\s+\S+\s+\S+)(\s*#.*)?\s*$" /etc/fstab && sed -ri "s#^(\s*\S+\s+)/dev/shm(\s+\S+\s+\S+)(\s+\S+\s+\S+)(\s*#.*)?\s*$#\1/dev/shm\2nodev\3\4##" /etc/fstab
[root#ip-172-35-24-37 ec2-user]#
And it worked.
You can use something else besides # for a delimiter like ! or ? or %. Just don't use / if you have dir paths.
This should be easy but i just can't get out of it:
I need to replace a piece of text in a .php file using the unix command-line.
using: sudo sed -i '' 's/STRING/REPLACEMENT/g' /file.php (The quotes after -i are needed because it runs on Mac Os X)
The string: ['password'] = ""; needs to be replaced by: ['password'] = "$PASS";
$PASS is a variable, so it gets filled in.
I got up to something like:
sudo sed -i '' 's/[\'password\'] = ""\;/[\'password\'] = "$PASS"\;/g' /file.php
But as i'm new with UNIX i don't know what to escape...
What should be changed? Thanks!
Unfortunately sed cannot robustly handle variables that might contain various characters that are "special" to sed and shell. You need to use awk for this, e.g. with GNU awk for gensub():
gawk -v pass="$PASS" '{$0=gensub(/(\[\047password\047] = \")/,"\\1"pass,"g")}1' file
See how sed fails below when PASS contains a forward slash but awk doesn't care:
$ cat file
The string: ['password'] = ""; needs to be replaced
$ PASS='foo'
$ awk -v pass="$PASS" '{$0=gensub(/(\[\047password\047] = \")/,"\\1"pass,"g")}1' file
The string: ['password'] = "foo"; needs to be replaced
$ sed "s/\(\['password'\] = \"\)\(\";\)/\1$PASS\2/g" file
The string: ['password'] = "foo"; needs to be replaced
$ PASS='foo/bar'
$ awk -v pass="$PASS" '{$0=gensub(/(\[\047password\047] = \")/,"\\1"pass,"g")}1' file
The string: ['password'] = "foo/bar"; needs to be replaced
$ sed "s/\(\['password'\] = \"\)\(\";\)/\1$PASS\2/g" file
sed: -e expression #1, char 38: unknown option to `s'
You need to use \047 or some other method (e.g. '"'"' if you prefer) to represent a single quote within an awk script that's single-quote-delimitted.
In awks without gensub() you just use gsub() instead:
awk -v pass="$PASS" '{pre="\\[\047password\047] = \""; gsub(pre,pre pass)}1' file
if you want to expand variable in sed, you have to use double quote, so something like
sed -i... "s/.../.../g" file
that is, you don't have to escape those single quotes, also you could use group reference to save some typing. you could try:
sudo sed -i '' "s/\(\['password'\] = \"\)\(\";\)/\1$PASS\2/g" /file.php