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clarified input/output filenames; updated step 3 wording; added step "4" of capturing output
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Jeff Schaller ♦
Jeff Schaller ♦
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header=$(head -n 1 fileinput) (printf "%s\n" "$header"; grep -vFxe "$header" fileinput ) > newfileoutput
  1. grab the header line from the input file into a variable
  2. print the header
  3. process the file with grep to omit lines that look likematch the header header
  4. capture the output from the above two steps into the output file
header=$(head -n 1 file) (printf "%s\n" "$header"; grep -vFxe "$header" file ) > newfile
  1. grab the header line into a variable
  2. print the header
  3. process the file with grep to omit lines that look like the header
header=$(head -n 1 input) (printf "%s\n" "$header"; grep -vFxe "$header" input ) > output
  1. grab the header line from the input file into a variable
  2. print the header
  3. process the file with grep to omit lines that match the header
  4. capture the output from the above two steps into the output file
you already " omit lines that look like the header" with 'grep' there's no need to ditch the 1st one via 'tail'
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don_crissti
don_crissti
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header=$(head -n 1 file) (printf "%s\n" "$header"; tail -n +2 file|grepgrep -vFxe "$header" file ) > newfile
  1. grab the header line into a variable
  2. print the header
  3. print everything exceptprocess the first line, andfile with grep to omit lines that look like the header
header=$(head -n 1 file) (printf "%s\n" "$header"; tail -n +2 file|grep -vFxe "$header" ) > newfile
  1. grab the header line into a variable
  2. print the header
  3. print everything except the first line, and omit lines that look like the header
header=$(head -n 1 file) (printf "%s\n" "$header"; grep -vFxe "$header" file ) > newfile
  1. grab the header line into a variable
  2. print the header
  3. process the file with grep to omit lines that look like the header
Adding -F for fixed string search, -x for whole line, -e to avoid problem with headers starting with "-". tail as a more obvious command to print the tail.
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Stéphane Chazelas
Stéphane Chazelas
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header=$(head -n 1 file) (printf "%s\n" "$header"; sedtail 1d-n +2 file|grep -vvFxe "^$header$""$header" ) > newfile
  1. grab the header line into a variable
  2. print the header
  3. print everything except the first line, and omit lines that look like the header
header=$(head -n 1 file) (printf "%s\n" "$header"; sed 1d file|grep -v "^$header$" ) > newfile
  1. grab the header line into a variable
  2. print the header
  3. print everything except the first line, and omit lines that look like the header
header=$(head -n 1 file) (printf "%s\n" "$header"; tail -n +2 file|grep -vFxe "$header" ) > newfile
  1. grab the header line into a variable
  2. print the header
  3. print everything except the first line, and omit lines that look like the header
added 2 characters in body
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Jeff Schaller ♦
Jeff Schaller ♦
  • 68.8k
  • 35
  • 122
  • 266
Source Link
Jeff Schaller ♦
Jeff Schaller ♦
  • 68.8k
  • 35
  • 122
  • 266