Revisions to sed: multi-line replace of config block

found a little bug in awk command.

Source Link

edit approved Oct 12, 2015 at 17:16

3
1

If you want to use sed, you can read from a named pipe. Beware that this code doesn't try to cope with errors. The script will block if the dynamic block header is present more than once.

CONTENT_URL="http://$SERVER/get_config.php"
tmp=$(mktemp -d)
(
  cd "$tmp"
  mkfifo dynamic_seen dynamic_content
  : >dynamic_seen & seen_pid=$!
  wget -O dynamic_content "$CONTENT_URL" & wget_pid=$!
  sed -e '/^# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY$/ p' \
      -e '/^# END DYNAMIC BLOCK$/ {'
          -e p -e 'r dynamic_seen' -e 'r dynamic_content' -e '}' \
      -e '/^# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY$/, /^# END DYNAMIC BLOCK$/ d'
  if ! kill $dynamic_seen 2>/dev/null; then
    # The pipe hasn't been read, so there was no dynamic block. Add one.
    echo "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY"
    cat dynamic_pipe
    echo "# END DYNAMIC BLOCK - DO NOT EDIT MANUALLY"
  fi
)
rm -rf "$tmp"

But I'd go for awk.

export CONTENT_URL="http://$SERVER/get_config.php"
awk '
    $0 == "# END DYNAMIC BLOCK"BLOCK - DO NOT EDIT MANUALLY" {skip=0; system("wget \"$CONTENT_URL\""); substituted=1}
    !skip {print}
    $0 == "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY" {skip=1}
    END {
         if (!substituted) {
            print "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY";
            system("wget \"$CONTENT_URL\"");
            print "# END DYNAMIC BLOCK - DO NOT EDIT MANUALLY";
        }
    }
'

If you want to use sed, you can read from a named pipe. Beware that this code doesn't try to cope with errors. The script will block if the dynamic block header is present more than once.

CONTENT_URL="http://$SERVER/get_config.php"
tmp=$(mktemp -d)
(
  cd "$tmp"
  mkfifo dynamic_seen dynamic_content
  : >dynamic_seen & seen_pid=$!
  wget -O dynamic_content "$CONTENT_URL" & wget_pid=$!
  sed -e '/^# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY$/ p' \
      -e '/^# END DYNAMIC BLOCK$/ {'
          -e p -e 'r dynamic_seen' -e 'r dynamic_content' -e '}' \
      -e '/^# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY$/, /^# END DYNAMIC BLOCK$/ d'
  if ! kill $dynamic_seen 2>/dev/null; then
    # The pipe hasn't been read, so there was no dynamic block. Add one.
    echo "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY"
    cat dynamic_pipe
    echo "# END DYNAMIC BLOCK - DO NOT EDIT MANUALLY"
  fi
)
rm -rf "$tmp"

But I'd go for awk.

export CONTENT_URL="http://$SERVER/get_config.php"
awk '
    $0 == "# END DYNAMIC BLOCK" {skip=0; system("wget \"$CONTENT_URL\""); substituted=1}
    !skip {print}
    $0 == "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY" {skip=1}
    END {
         if (!substituted) {
            print "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY";
            system("wget \"$CONTENT_URL\"");
            print "# END DYNAMIC BLOCK - DO NOT EDIT MANUALLY";
        }
    }
'

If you want to use sed, you can read from a named pipe. Beware that this code doesn't try to cope with errors. The script will block if the dynamic block header is present more than once.

CONTENT_URL="http://$SERVER/get_config.php"
tmp=$(mktemp -d)
(
  cd "$tmp"
  mkfifo dynamic_seen dynamic_content
  : >dynamic_seen & seen_pid=$!
  wget -O dynamic_content "$CONTENT_URL" & wget_pid=$!
  sed -e '/^# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY$/ p' \
      -e '/^# END DYNAMIC BLOCK$/ {'
          -e p -e 'r dynamic_seen' -e 'r dynamic_content' -e '}' \
      -e '/^# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY$/, /^# END DYNAMIC BLOCK$/ d'
  if ! kill $dynamic_seen 2>/dev/null; then
    # The pipe hasn't been read, so there was no dynamic block. Add one.
    echo "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY"
    cat dynamic_pipe
    echo "# END DYNAMIC BLOCK - DO NOT EDIT MANUALLY"
  fi
)
rm -rf "$tmp"

But I'd go for awk.

export CONTENT_URL="http://$SERVER/get_config.php"
awk '
    $0 == "# END DYNAMIC BLOCK - DO NOT EDIT MANUALLY" {skip=0; system("wget \"$CONTENT_URL\""); substituted=1}
    !skip {print}
    $0 == "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY" {skip=1}
    END {
         if (!substituted) {
            print "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY";
            system("wget \"$CONTENT_URL\"");
            print "# END DYNAMIC BLOCK - DO NOT EDIT MANUALLY";
        }
    }
'

do print the header of the dynamic block (thanks elias); add the dynamic block at the end if it wasn't present

Source Link

edited Jun 13, 2015 at 0:06

Gilles 'SO- stop being evil'

865.3k
205
1.8k
2.3k

If you want to use sed, you can read from a named pipe:. Beware that this code doesn't try to cope with errors. The script will block if the dynamic block header is present more than once.

CONTENT_URL="http://$SERVER/get_config.php"
tmp=$(mktemp -d)
(
  cd "$tmp"
  mkfifo dynamicdynamic_seen dynamic_content
  : >dynamic_seen & seen_pid=$!
  wget -O dynamicdynamic_content "$CONTENT""$CONTENT_URL" & wget_pid=$!
  sed -e '/^# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY$/ p' \
      -e '/^# END DYNAMIC BLOCK$/ {'
          -e p -e 'r dynamic'dynamic_seen' -e 'r dynamic_content' -e '}' \
      -e '/^# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY$/, /^# END DYNAMIC BLOCK$/ d'
  if ! kill $wget_pid$dynamic_seen 2>/dev/null; then
    # The pipe hasn't been read, so there was no dynamic block. Add one.
    echo "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY"
    cat dynamic_pipe
    echo "# END DYNAMIC BLOCK - DO NOT EDIT MANUALLY"
  fi
)
rm -rf "$tmp"

But I'd go for awk.

export CONTENTCONTENT_URL="http://$SERVER/get_config.php"
awk '
    $0 == "# END DYNAMIC BLOCK" {skip=0; system("wget \"$CONTENT_URL\""); substituted=1}
    !skip {print}
    $0 == "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY" {skip=1; nextskip=1}
    $0END =={
         if (!substituted) {
            print "# ENDBEGIN DYNAMIC BLOCK"BLOCK {skip=0;- DO NOT EDIT MANUALLY";
            system("wget $CONTENT"\"$CONTENT_URL\"")};
    !skip {       print "# END DYNAMIC BLOCK - DO NOT EDIT MANUALLY";
        }
    }
'

If you want to use sed, you can read from a named pipe:

tmp=$(mktemp -d)
(
  cd "$tmp"
  mkfifo dynamic
  wget -O dynamic "$CONTENT" & wget_pid=$!
  sed -e '/^# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY$/ p' \
      -e '/^# END DYNAMIC BLOCK$/ {' -e p -e 'r dynamic' -e '}' \
      -e '/^# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY$/, /^# END DYNAMIC BLOCK$/ d'
  kill $wget_pid
)
rm -rf "$tmp"

But I'd go for awk.

export CONTENT
awk '
    $0 == "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY" {skip=1; next}
    $0 == "# END DYNAMIC BLOCK" {skip=0; system("wget $CONTENT")}
    !skip {print}
'

If you want to use sed, you can read from a named pipe. Beware that this code doesn't try to cope with errors. The script will block if the dynamic block header is present more than once.

CONTENT_URL="http://$SERVER/get_config.php"
tmp=$(mktemp -d)
(
  cd "$tmp"
  mkfifo dynamic_seen dynamic_content
  : >dynamic_seen & seen_pid=$!
  wget -O dynamic_content "$CONTENT_URL" & wget_pid=$!
  sed -e '/^# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY$/ p' \
      -e '/^# END DYNAMIC BLOCK$/ {'
          -e p -e 'r dynamic_seen' -e 'r dynamic_content' -e '}' \
      -e '/^# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY$/, /^# END DYNAMIC BLOCK$/ d'
  if ! kill $dynamic_seen 2>/dev/null; then
    # The pipe hasn't been read, so there was no dynamic block. Add one.
    echo "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY"
    cat dynamic_pipe
    echo "# END DYNAMIC BLOCK - DO NOT EDIT MANUALLY"
  fi
)
rm -rf "$tmp"

But I'd go for awk.

export CONTENT_URL="http://$SERVER/get_config.php"
awk '
    $0 == "# END DYNAMIC BLOCK" {skip=0; system("wget \"$CONTENT_URL\""); substituted=1}
    !skip {print}
    $0 == "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY" {skip=1}
    END {
         if (!substituted) {
            print "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY";
            system("wget \"$CONTENT_URL\"");
            print "# END DYNAMIC BLOCK - DO NOT EDIT MANUALLY";
        }
    }
'

Source Link

answered Jan 3, 2013 at 2:05

Gilles 'SO- stop being evil'

865.3k
205
1.8k
2.3k

If you want to use sed, you can read from a named pipe:

tmp=$(mktemp -d)
(
  cd "$tmp"
  mkfifo dynamic
  wget -O dynamic "$CONTENT" & wget_pid=$!
  sed -e '/^# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY$/ p' \
      -e '/^# END DYNAMIC BLOCK$/ {' -e p -e 'r dynamic' -e '}' \
      -e '/^# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY$/, /^# END DYNAMIC BLOCK$/ d'
  kill $wget_pid
)
rm -rf "$tmp"

But I'd go for awk.

export CONTENT
awk '
    $0 == "# BEGIN DYNAMIC BLOCK - DO NOT EDIT MANUALLY" {skip=1; next}
    $0 == "# END DYNAMIC BLOCK" {skip=0; system("wget $CONTENT")}
    !skip {print}
'

Stack Exchange Network

Return to Answer