Sed on AIX does not recognize -i flag - sed

Does sed -i work on AIX?
If not, how can I edit a file "in place" on AIX?

The -i option is a GNU (non-standard) extension to the sed command. It was not part of the classic interface to sed.
You can't edit in situ directly on AIX. You have to do the equivalent of:
sed 's/this/that/' infile > tmp.$$
mv tmp.$$ infile
You can only process one file at a time like this, whereas the -i option permits you to achieve the result for each of many files in its argument list. The -i option simply packages this sequence of events. It is undoubtedly useful, but it is not standard.
If you script this, you need to consider what happens if the command is interrupted; in particular, you do not want to leave temporary files around. This leads to something like:
tmp=tmp.$$ # Or an alternative mechanism for generating a temporary file name
for file in "$#"
do
trap "rm -f $tmp; exit 1" 0 1 2 3 13 15
sed 's/this/that/' $file > $tmp
trap "" 0 1 2 3 13 15
mv $tmp $file
done
This removes the temporary file if a signal (HUP, INT, QUIT, PIPE or TERM) occurs while sed is running. Once the sed is complete, it ignores the signals while the mv occurs.
You can still enhance this by doing things such as creating the temporary file in the same directory as the source file, instead of potentially making the file in a wholly different file system.
The other enhancement is to allow the command (sed 's/this/that' in the example) to be specified on the command line. That gets trickier!
You could look up the overwrite (shell) command that Kernighan and Pike describe in their classic book 'The UNIX Programming Environment'.

#!/bin/ksh
host_name=$1
perl -pi -e "s/#workerid#/$host_name/g" test.conf
Above will replace #workerid# to $host_name inside test.conf

You can simply install GNU version of Unix commands on AIX :
http://www-03.ibm.com/systems/power/software/aix/linux/toolbox/alpha.html

You can use a here construction with vi:
vi file >/dev/null 2>&1 <<#
:1,$ s/old/new/g
:wq
#
When you want to do things in the vi-edit mode, you will need an ESC.
For an ESC press CTRL-V ESC.
When you use this in a non-interactive mode, vi can complain about the TERM not set. The solution is adding export TERM=vt100 before calling vi.

Another option is to use good old ed, like this:
ed fileToModify <<EOF
,s/^ff/gg/
w
q
EOF

you can use perl to do it :
perl -p -i.bak -e 's/old/new/g' test.txt
is going to create a .bak file.

Related

Cross-platform compatible sed command?

I'm trying to use sed, but I want to run properly both under Linux and Mac. Currently, I have something like this:
if test -f ${GENESISFILE};
then
echo "Replacing ..."
sed -i '' "s/ADDRESS/${ADDRESS}/g" ${GENESISFILE}
else
echo "No such file"
fi
Now, the point is that using -i '' part it runs properly under Mac, but doesn't under Linux, and if I remove it then it doesn't work under Mac. What's proper way to make it cross-platform compatible?
Instead of sed one-liner:
sed -i '' "s/ADDRESS/${ADDRESS}/g" ${GENESISFILE}
use this cross-platform Perl one-liner, which runs OK on both Linux and macOS:
perl -i.bak -pe 's/ADDRESS/$ENV{ADDRESS}/g' ${GENESISFILE}
The Perl one-liner uses these command line flags:
-e : Tells Perl to look for code in-line, instead of in a file.
-p : Loop over the input one line at a time, assigning it to $_ by default. Add print $_ after each loop iteration.
-i.bak : Edit input files in-place (overwrite the input file). Before overwriting, save a backup copy of the original file by appending to its name the extension .bak. Use -i alone, without .bak, to skip making the backup.
SEE ALSO:
perldoc perlrun: how to execute the Perl interpreter: command line switches

Perl using the -i option on a vboxsf share: Can't remove input_file Text file busy, skipping file

System: Arch Linux in VirtualBox 5.1.26 on Windows 10 Host
I try to use perl like sed in the terminal for in place substitution the input file:
perl -i -p -e 's/orig/replace/g' input_file
But I always get:
Can't remove input_file Text file busy, skipping file
This happens only if the file is inside a VirtualBox vboxsf share. With all other tools (sed, mv, vim or whatever) it is no problem to change the file.
This problem seems to be related to:
https://www.virtualbox.org/ticket/2553
https://forums.virtualbox.org/viewtopic.php?t=4437
I can't find any solution googling around :(
Update:
Using perl -i.bak -p -e 's/orig/replace/g' input_file I get a similar message:
Can't rename input_file to input_file.bak: Text file busy, skipping file.
This is exactly the same message as gedit shows:
So it is the same behavior, but googling around I can only find the Gedit topic. It seems noone has noticed this with perl -i.
While you are running a unix OS, you are still using a Windows file system. NTFS doesn't support anonymous files like unix file systems, and Perl -i requires support for anonymous files.
The workaround is to use a temporary files by using -i<ext> (e.g. -i~) instead of -i.
I have same problem. My solution is a bashscript. Copy files to tmp. Search and Replace. Overwrite tmp-files with original-files. Than delete tmp-dir. If you need you can use parameter in script for dynamic search&replace and create an alias for call the script direct and everywhere.
#!/bin/bash
echo "Removing text from .log files..."
echo "Creating tmp-dir..."
mkdir /tmp/myTmpFiles/
echo "Copy .log files to tmp..."
cp -v /home/user/sharedfolder/*.log /tmp/myTmpFiles/
echo "Search and Replace in tmp-files..."
perl -i -p0e 's/orig/replace/g' /tmp/myTmpFiles/*.log
echo "Copy .log to sharedfolder"
cp -v /tmp/myTmpFiles/*.log /home/user/sharedfolder/
echo "Remove tmp-dir..."
rm -vr /tmp/myTmpFiles/
echo "Done..."

Using sed and mv to add characters to files

First off, I'd like to say that I know this is almost an exact duplicate of some posts that I've read, but have not had any luck with referencing.
I have 100+ files that all follow a very strict naming convention of 5_##_<name>.ext My issue was that when originally making these files I failed to realise that 5_100_ and above would mess up my ordering.
I am now trying to append a 0 in front of every number between 01 and 99. I've written a bash script using sed that works for the file contents (the file name is in the file as well):
#!/bin/bash
for fl in *.tcl; do
echo Filename: $fl
#sed -i 's/5_\(..\)_/5_0\1_/g' $fl
done
However, this only changes the contents and not the filename itself. I've read that mv is the solution (rename is simpler but I do not have it on my system). My current incarnation of my multiple attempts is:
mv "$fl" $(echo "$file" | sed -e 's/5_\(..\)_/5_0\1_/g') but it gives me an error: mv: missing destination file operand after <filename>
Again, I'm sorry about the duplicate but I wasn't able to solve my issue by reading it. I'm sure I'm just using the combination of mv and sed incorrectly.
Solution was entered in the comments. I was using $file instead of $fl.
Something like this might be useful:
for n in $(seq 99)
do
prefix2="5_$(printf "%02d" ${n})_"
prefix3="5_$(printf "%03d" ${n})_"
for f in ${prefix2}*.tcl
do
suffix="${f#${prefix2}}"
[[ -r "${prefix3}${suffix}" ]] || mv "${prefix2}${suffix}" "${prefix3}${suffix}"
done
done
Rather than processing every single file, it only looks at the ones that currently have a "5_XX_" prefix, and only renames them if the corresponding "5_XXX_" file doesn't already exist...
#!/bin/bash
for fl in *.tcl
do
NewName="$(echo "${fl} | sed '/^5_[0-9]\{2\}_/ s/../&0/' )"
#echo "Filename: ${fl} -> ${NewName}
[ ! "${fl}" = "${NewName}" ] && mv ${fl} ${NewName}
done
With a bit a securisation a allow to pass several time on same folder (changing only needed one).
Under linux (non posix sed by default), use sed --posix instead of simple sed call

Why do I have to specify the -i switch with a backup extension when using ActivePerl?

I cannot get in-place editing Perl one-liners running under ActivePerl to work unless I specify them with a backup extension:
C:\> perl -i -ape "splice (#F, 2, 0, q(inserted text)); $_ = qq(#F\n);" file1.txt
Can't do inplace edit without backup.
The same command with -i.bak or -i.orig works a treat but creates an unwanted backup file in the process.
Is there a way around this?
This is a Windows/MS-DOS limitation. According to perldiag:
You're on a system such as MS-DOS that gets confused if you try reading from a deleted (but still opened) file. You have to say -i.bak, or some such.
Perl's -i implementation causes it to delete file1.txt while keeping an open handle to it, then re-create the file with the same name. This allows you to 'read' file1.txt even though it has been deleted and is being re-created. Unfortunately, Windows/MS-DOS does not allow you to delete a file that has an open handle attached to it, so this mechanism does not work.
Your best shot is to use -i.bak and then delete the backup file. This at least gives you some protection - for example, you could opt not to delete the backup if perl exits with a non-zero exit code. Something like:
perl -i.bak -ape "splice...." file1.txt && del file1.bak
Sample with recursive modify and delete both done by find. Works on e.g. mingw git bash on windows.
$ find . -name "*.xml" -print0 | xargs -0 perl -p -i.bak -e 's#\s*<property name="blah" value="false" />\s*##g'
$ find . -name "*.bak" -print0 | xargs -0 rm
Binary terminated values passed between find/xargs to handle spaces. Unusual s/ prefix to avoid mangling xml in search term. This assumes you didn't have any .bak files hanging around to begin.

Single sed command for multiple substitutions?

I use sed to substitute text in files.
I want to give sed a file which contains all the strings to be searched and replaced in a given file.
It goes over .h and .cpp files. In each file it searches for file names which are included in it. If found, it substitutes for example "a.h" with "<a.h>" (without the quotes).
The script is this:
For /F %%y in (all.txt) do
for /F %%x in (allFilesWithH.txt) do
sed -i s/\"%%x\"/"\<"%%x"\>"/ %%y
all.txt - List of files to do the substitution in them
allFilesWithH.txt - All the include names to be searched
I don't want to run sed several times (as the number of files names in input.txt.) but I want to run a single sed command and pass it input.txt as input.
How can I do it?
P.S I run sed from VxWorks Development shell, so it doesn't have all the commands that the Linux version does.
You can eliminate one of the loops so sed only needs to be called once per file. Use
the -f option to specify more than one substitution:
For /F %%y in (all.txt) do
sed -i -f allFilesWithHAsSedScript.sed %%y
allFilesWithHAsSedScript.sed derives from allFilesWithH.txt and would contain:
s/\"file1\"/"\<"file1"\>"/
s/\"file2\"/"\<"file2"\>"/
s/\"file3\"/"\<"file3"\>"/
s/\"file4\"/"\<"file4"\>"/
(In the article Common threads: Sed by example, Part 3 there are many examples of sed scripts with explanations.)
Don't get confuSed (pun intended).
sed itself has no capability to read filenames from a file. I'm not familiar with the VxWorks shell, and I imagine this is something to do with the lack of answers... So here are some things that would work in bash - maybe VxWorks will support one of these things.
sed -i 's/.../...' `cat all.txt`
sed -i 's/.../...' $(cat all.txt)
cat all.txt | xargs sed -i 's/.../...'
And really, it's no big deal to invoke sed several times if it gets the job done:
cat all.txt | while read file; do sed -i 's/.../.../' $file; done
for file in $(cat all.txt); do # or `cat all.txt`
sed -i 's/.../.../' $file
done
What I'd do is change allFilesWithH.txt into a sed command using sed.
(When forced to use sed. I'd actually use Perl instead, it can also do the search for *.h files.)