Save modifications in place with awk

Question

I am learning awk and I would like to know if there is an option to write changes to file  similar to sed where I would use -i option to save modifications to a file    I do understand that I could use redirection to write changes  However is there an option in awk to do that

User · Answer

An alternative is to use sponge   awk   print  0   your file   sponge your file   Where you replace   print  0   by your awk script and your file by the name of the file you want to edit in place   sponge absorbs entirely the input before saving it to the file

User · Answer

Using tee   awk   awk code   file   tee file   the tee command take place and executed after the awk command is finished due to the

User · Answer

Unless you have GNU awk 4 1 0 or later     You won t have such an option as sed s -i option so instead do     awk   print  0   file  gt  tmp  amp  amp  mv tmp file   Note  the -i is not magic  it is also creating a temporary file sed just handles it for you     As of GNU awk 4 1 0     GNU awk added this functionality in version 4 1 0  released 10 05 2013   It is not as straight forwards as just giving the -i option as described in the released notes      The new -i option  from xgawk  is used for loading awk library files     This differs from -f in that the first non-option argument   is treated as a script    You need to use the bundled inplace awk include file to invoke the extension properly like so     cat file 123 abc 456 def 789 hij    gawk -i inplace   print  1   file    cat file 123 456 789   The variable INPLACE SUFFIX can be used to specify the extension for a backup file     gawk -i inplace -v INPLACE SUFFIX  bak   print  1   file    cat file 123 456 789    cat file bak 123 abc 456 def 789 hij   I am happy this feature has been added but to me  the implementation isn t very awkish as the power comes from the conciseness of the language and -i inplace is 8 characters too long i m o    Here is a link to the manual for the official word

User · Answer

just a little hack that works  echo    awk   awk code   file    gt  file

User · Answer

sudo O has the right answer   This can t work    someprocess  lt  file  gt  file   The shell performs the redirections before handing control over to someprocess  redirections   The  gt  redirection will truncate the file to zero size  redirecting output   Therefore  by the time someprocess gets launched and wants to read from the file  there is no data for it to read

User · Answer

In GNU Awk 4 1 0  released 2013  and later  it has the option of  quot inplace quot  file editing         The  quot inplace quot  extension  built using the new facility  can be used to simulate the GNU  quot sed -i quot  feature         Example usage    gawk -i inplace    gsub  foo    quot bar quot        print    file1 file2 file3  To keep the backup    gawk -i inplace -v INPLACE SUFFIX  bak    gsub  foo    quot bar quot      gt    print    file1 file2 file3

User · Answer

In case you want an awk-only solution without creating a temporary file and usable with version   gawk 4 1 0    awk   a b     0  END  for c 0 c lt  b c   print a c  gt ARGV 1    file

User · Answer

following won t work  echo   awk   awk code   file   gt  file   this should work  echo    awk   awk code   file    gt  file

[linux] Save modifications in place with awk

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