1 files changed, 116 insertions, 0 deletions
diff --git a/awklib/eg/prog/uniq.awk b/awklib/eg/prog/uniq.awk
new file mode 100644
index 00000000..5f63ef0f
--- /dev/null
+++ b/awklib/eg/prog/uniq.awk
@@ -0,0 +1,116 @@
+# uniq.awk --- do uniq in awk
+# Arnold Robbins, arnold@gnu.ai.mit.edu, Public Domain
+# May 1993
+
+function usage(    e)
+{
+    e = "Usage: uniq [-udc [-n]] [+n] [ in [ out ]]"
+    print e > "/dev/stderr"
+    exit 1
+}
+
+# -c    count lines. overrides -d and -u
+# -d    only repeated lines
+# -u    only non-repeated lines
+# -n    skip n fields
+# +n    skip n characters, skip fields first
+
+BEGIN    \
+{
+    count = 1
+    outputfile = "/dev/stdout"
+    opts = "udc0:1:2:3:4:5:6:7:8:9:"
+    while ((c = getopt(ARGC, ARGV, opts)) != -1) {
+        if (c == "u")
+            non_repeated_only++
+        else if (c == "d")
+            repeated_only++
+        else if (c == "c")
+            do_count++
+        else if (index("0123456789", c) != 0) {
+            # getopt requires args to options
+            # this messes us up for things like -5
+            if (Optarg ~ /^[0-9]+$/)
+                fcount = (c Optarg) + 0
+            else {
+                fcount = c + 0
+                Optind--
+            }
+        } else
+            usage()
+    }
+
+    if (ARGV[Optind] ~ /^\+[0-9]+$/) {
+        charcount = substr(ARGV[Optind], 2) + 0
+        Optind++
+    }
+
+    for (i = 1; i < Optind; i++)
+        ARGV[i] = ""
+
+    if (repeated_only == 0 && non_repeated_only == 0)
+        repeated_only = non_repeated_only = 1
+
+    if (ARGC - Optind == 2) {
+        outputfile = ARGV[ARGC - 1]
+        ARGV[ARGC - 1] = ""
+    }
+}
+function are_equal(    n, m, clast, cline, alast, aline)
+{
+    if (fcount == 0 && charcount == 0)
+        return (last == $0)
+
+    if (fcount > 0) {
+        n = split(last, alast)
+        m = split($0, aline)
+        clast = join(alast, fcount+1, n)
+        cline = join(aline, fcount+1, m)
+    } else {
+        clast = last
+        cline = $0
+    }
+    if (charcount) {
+        clast = substr(clast, charcount + 1)
+        cline = substr(cline, charcount + 1)
+    }
+
+    return (clast == cline)
+}
+NR == 1 {
+    last = $0
+    next
+}
+    
+{
+    equal = are_equal()
+
+    if (do_count) {    # overrides -d and -u
+        if (equal)
+            count++
+        else {
+            printf("%4d %s\n", count, last) > outputfile
+            last = $0
+            count = 1    # reset
+        }
+        next
+    }
+
+    if (equal)
+        count++
+    else {
+        if ((repeated_only && count > 1) ||
+            (non_repeated_only && count == 1))
+                print last > outputfile
+        last = $0
+        count = 1
+    }
+}
+
+END {
+    if (do_count)
+        printf("%4d %s\n", count, last) > outputfile
+    else if ((repeated_only && count > 1) ||
+            (non_repeated_only && count == 1))
+        print last > outputfile
+}