Linux Commands Examples

A great documentation place for Linux commands

replace

a string-replacement utility

Synopsis

replace arguments


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Can I replace Windows with Wine?

I would first check to see if the games that you are playing have a Linux port already. This way you could avoid using Wine or Parallels in order to play them.

I haven't had great experience running newer windows games (especially newer FPS titles) through an emulator such as Wine.

As far as partitioning your HDD to dual boot windows and linux, if you are going to be in windows most of the time playing games, I would devote about 60% of the HDD space to windows and the other 40% to your linux installation.

Windows cannot read ext4 partitions AFAIK. Although I do believe that there are a few programs out there that will let you browse the partitions from within windows.

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Replaces images\(.*)" with images/\1" in all files?

Check if this works for you

sed "s/images\\\/images\\//g"

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Automatic replacement of expressions

What you are looking for is called "Pattern Capture", where a particular pattern matched by a regular expression is saved in a variable. The details of how this is done depend on the language used (Perl, awk, sed or whatever).

Your problem is a bit more complicated because:

  1. You should not parse HTML with regular expressions

  2. Regular expressions become more complicated in most languages when your search pattern spans multiple lines.

  3. Since you have not included a sample of your actual code, it is harder for me to find a unique pattern with which to anchor my regular expression. In the script below I am using <moreCodeThatAlwaysStaysTheSame> and .someCodeAndOth you will need to change that to reflect actual unique patterns that flank the text you want to replace.

  4. You should not parse HTML with regular expressions

All that said, here is a Perl script that will replace the patterns you gave in your question:

#!/usr/bin/perl 
###############################################
# This sets the line separator to a string    #
# instead of a new line (\n). Use something   #
# that uniquely delimits the code you want to #
# replace.                                    #
###############################################
local $/="<moreCodeThatAlwaysStaysTheSame>";

#######################################################
# Read the input file, line by line. Remember that    #
# because of the previous command, a line is expected #
# to end with "<moreCodeThatAlwaysStaysTheSame>"      #
#######################################################
while (<>) {
#####################################################
# $str is what we want to replace the pattern with. #
# "XXX" will be replaced by the correct mp3.        #
#####################################################
    my $str=<<Eof;
 <audio controls="controls">
   <source src="XXXX" type="audio/mpeg">
<embed height="50" width="100" src="XXXX">
</audio>
Eof
###########################################################
# Match the entire string we will replace AND the         #
# mp3 we are looking for. In Perl (and other languages)   #
# placing a regex pattern in (parentheses) captures it.   #
# We can now refer to the 1st captured pattern as $1, the #
# second as $2 etc.                                       #
###########################################################
    /(.someCodeAndOth.+?src=.+\/(.+?\.mp3).+?$)/s;

###################################################
# Save the matches into variables, otherwise they #
# will be lost at the next match operation.       #
###################################################
    my ($match,$rep,$mp3)=($1,$1,$2);

###################################################
# Replace "XXXX" with the appropriate mp3 in $str #
###################################################
    $str=~s/XXXX/$mp3/g;

#########################################
# Replace the matched pattern with $str #
#########################################
    s/$match/$str/;

#################
# Print it out! #
#################
    print;
}

Save that script as foo.pl and run it on your file as follows:

perl foo.pl input_file.html > output_file.html

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How do I exclude match and change only specific character with sed

From your code snippet, the sed expression looks correct - it will replace every '0' character with the characters 'correct'. If you only want the output from your echo command to be updated, you could put the sed command on the output from echo, eg:

some command
date >> /file.txt
echo $? | sed 's/0/correct/' >> /file.txt

(note removing 'echo' and 'cat' commands will have no effect on the output)

In the context you're using the -i option, it's actually a commandline option, rather than a sed script command - it's a different section in the man page:

       -i[SUFFIX], --in-place[=SUFFIX]

          edit files in place (makes backup if extension supplied)

This means it will update the source file (which is precisely what you want in your example).

However, note that in this example, the exit code being checked is the exit code of date, and not your command. In fact in your example, it's checking the exit code of echo, which I suspect is even less helpful for you.

A more standard way of performing this check would be along the lines of:

some command
result=$?
date >> /file.txt
if [ $result -eq 0 ]
then
  echo "Command finished successfully" >> /file.txt
else
  echo "Command failed with exit code $result" >> /file.txt
fi

description

The replace utility program changes strings in place in files or on the standard input.

Invoke replace in one of the following ways:

shell> replace from to [from to] ... -- file_name [file_name] ...
shell> replace from to [from to] ... < file_name

from represents a string to look for and to represents its replacement. There can be one or more pairs of strings.

Use the -- option to indicate where the string-replacement list ends and the file names begin. In this case, any file named on the command line is modified in place, so you may want to make a copy of the original before converting it. replace prints a message indicating which of the input files it actually modifies.

If the -- option is not given, replace reads the standard input and writes to the standard output.

replace uses a finite state machine to match longer strings first. It can be used to swap strings. For example, the following command swaps a and b in the given files, file1 and file2:

shell> replace a b b a -- file1 file2 ...

The replace program is used by msql2mysql. See msql2mysql(1).

replace supports the following options.

-?, -I

Display a help message and exit.

-#debug_options

Enable debugging.

-s

Silent mode. Print less information what the program does.

-v

Verbose mode. Print more information about what the program does.

-V

Display version information and exit.

copyright

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see also

For more information, please refer to the MySQL Reference Manual, which may already be installed locally and which is also available online at http://dev.mysql.com/doc/.


author

Oracle Corporation (http://dev.mysql.com/).

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