tkevans@fallst.UUCP (Tim Evans) (06/29/90)
Can someone help me to delete the _first_ occurring blank line of a file
(whereever it occurs) without deleting subsequent ones?
You'd think the following would work, but it doesn't:
sed 's/^$//1' foo > newfoo
Solutions other than those using 'perl' are preferred.
Thanks
--
UUCP: {rutgers|ames|uunet}!mimsy!woodb!fallst!tkevans
INTERNET: tkevans%fallst@wb3ffv.ampr.org
Tim Evans 2201 Brookhaven Ct, Fallston, MD 21047rostamia@umbc3.UMBC.EDU (Rouben Rostamian) (06/30/90)
In article <1651@fallst.UUCP> tkevans@fallst.UUCP (Tim Evans) writes: >Can someone help me to delete the _first_ occurring blank line of a file >(whereever it occurs) without deleting subsequent ones? I do not know to do this in sed, but here's how it can be done in ed: 1. Create a file "mystrip" containing: ed $1 << 'EOF' /^$/d w q 'EOF' 2. chmod u+x mystrip 3. To strip the first blank line in file "try", do mystrip try
rostamia@umbc3.UMBC.EDU (Rouben Rostamian) (07/01/90)
In article <1651@fallst.UUCP> tkevans@fallst.UUCP (Tim Evans) writes: >Can someone help me to delete the _first_ occurring blank line of a file >(whereever it occurs) without deleting subsequent ones? Here are two solutions using awk. In both cases it is assumed that the command is executed as a script, and $1 denotes the input file. Solution 1: awk < $1 'BEGIN{RS=""} { if (NR <= 2 ) print $0; else print "\n" $0; }' Solution 2: Note: Here X denotes a character which does not occur in the input file. Replace with a more suitable character. A control character, such as ^A, may be a good choice. awk < $1 'BEGIN{RS=""} {print $0; ORS=""; RS="X"}' --
merlyn@iwarp.intel.com (Randal Schwartz) (07/01/90)
In article <1651@fallst.UUCP>, tkevans@fallst (Tim Evans) writes: | Can someone help me to delete the _first_ occurring blank line of a file | (whereever it occurs) without deleting subsequent ones? | | You'd think the following would work, but it doesn't: | | sed 's/^$//1' foo > newfoo | | Solutions other than those using 'perl' are preferred. But, since you didn't say *necessary*, how about: perl -ne 'print unless /^$/ && $once++;' Easy, easy, easy. Just another Perl hacker, -- /=Randal L. Schwartz, Stonehenge Consulting Services (503)777-0095 ==========\ | on contract to Intel's iWarp project, Beaverton, Oregon, USA, Sol III | | merlyn@iwarp.intel.com ...!any-MX-mailer-like-uunet!iwarp.intel.com!merlyn | \=Cute Quote: "Welcome to Portland, Oregon, home of the California Raisins!"=/
leo@ehviea.ine.philips.nl (Leo de Wit) (07/01/90)
In article <1651@fallst.UUCP> tkevans@fallst.UUCP (Tim Evans) writes: |Can someone help me to delete the _first_ occurring blank line of a file |(whereever it occurs) without deleting subsequent ones? | |You'd think the following would work, but it doesn't: | | sed 's/^$//1' foo > newfoo Sure. It isn't valid sed syntax. | |Solutions other than those using 'perl' are preferred. Here's a quick and dirty one with sed: sed -n -e ' /^$/{ : back n p b back } p' foo >newfoo All lines before the first empty line are printed by the last 'p' command. Then, at the first empty line, each next line is read in and printed. Leo.
omerzu@quando.quantum.de (Thomas Omerzu) (07/02/90)
In article <819@ehviea.ine.philips.nl> leo@ehviea.UUCP (Leo de Wit) writes: >In article <1651@fallst.UUCP> tkevans@fallst.UUCP (Tim Evans) writes: >|Can someone help me to delete the _first_ occurring blank line of a file >|(whereever it occurs) without deleting subsequent ones? >| >|You'd think the following would work, but it doesn't: >| >| sed 's/^$//1' foo > newfoo > >Sure. It isn't valid sed syntax. NO! It is valid sed syntax. The reason, that this does not work as supposed is different: the pattern /^$/ matches any empty line. On the first occurency (indicated by '1'), this emptiness is replaced by //, i.e. nothing, and the line is p r i n t e d. And this is the actual problem: /^$/ does n o t include the '\n', which ist created by printing the empty line. -- *-----------------------------------------------------------------------------* Thomas Omerzu UUCP: ...!unido!quando!omerzu / omerzu@quando.uucp Quantum GmbH, Bitnet: UNIDO!quando!omerzu / omerzu%quando@UNIDO(.bitnet) Dortmund, Germany Internet: omerzu@quando.quantum.de
leo@ehviea.ine.philips.nl (Leo de Wit) (07/02/90)
In article <1607@quando.quantum.de> omerzu@quando.quantum.de (Thomas Omerzu) writes: | |In article <819@ehviea.ine.philips.nl> leo@ehviea.UUCP (Leo de Wit) writes: | |>In article <1651@fallst.UUCP> tkevans@fallst.UUCP (Tim Evans) writes: |>|Can someone help me to delete the _first_ occurring blank line of a file |>|(whereever it occurs) without deleting subsequent ones? |>| |>|You'd think the following would work, but it doesn't: |>| |>| sed 's/^$//1' foo > newfoo |> |>Sure. It isn't valid sed syntax. | | |NO! It is valid sed syntax. | (this is on Pyramid OSx): Script started on Mon Jul 2 07:22:27 1990 ehviea_leo> sed 's/^$//1' foo > newfoo command garbled: s/^$//1 ehviea_leo> exit ehviea_leo> script done on Mon Jul 2 07:22:48 1990 So it is at least non-portable. Leo.