Shell Programming and Scripting

awk '{print FILENAME "," $0}' file1 file2 file3

function abs(val) { return val > 0 ? val : -val }

BEGIN {
  ARGV[ARGC++] = ARGV[ARGC-1]
}

FNR == NR {
  />/ && idx[FNR] = ++i
  $2 || val[i] = $1
  next
}

FNR in idx { v = val[idx[FNR]] }

{ !/>/ && srdist = abs($1 - v) }

/>/ || NF == 2 && srdist < dsrmx { sub(/[ \t]+$/, ""); print }

function abs(val) { return val > 0 ? val : -val }

BEGIN {
  print ">"
  RS = ORS = ">"
}

#NR == 1 { print }

NF > 2 { if (abs($1 - $(NF-2)) < srmax) { print } }

{
  n = split(FILENAME, a, ".")
  ext = a[2]
  print ext
}

{
  split(FILENAME, a, ".")
  fext = a[2]

  if (fext == "xt") {
    print "Travel time file detected"
  } else if (fext == "ry") {
    print "Ray paths file detected"
  } else {
    print "Unrecognized file"
  }

  print fext
}

NF > 2 { if (abs($1 - $(NF-2)) < srmax) { print } }