Update egrep program to be POSIX compliant.

1 files changed, 41 insertions, 26 deletions

diff --git a/awklib/eg/prog/egrep.awk b/awklib/eg/prog/egrep.awk
index a4165a90..8ec5105b 100644
--- a/awklib/eg/prog/egrep.awk
+++ b/awklib/eg/prog/egrep.awk
@@ -2,58 +2,67 @@
 #
 # Arnold Robbins, arnold@skeeve.com, Public Domain
 # May 1993
+# Revised September 2020
 
 # Options:
 #    -c    count of lines
-#    -s    silent - use exit value
-#    -v    invert test, success if no match
+#    -e    argument is pattern
 #    -i    ignore case
 #    -l    print filenames only
-#    -e    argument is pattern
+#    -n    add line number to output
+#    -q    quiet - use exit value
+#    -s    silent - don't print errors
+#    -v    invert test, success if no match
+#    -x    the entire line must match
 #
-# Requires getopt and file transition library functions
+# Requires getopt library function
+# Uses IGNORECASE, BEGINFILE and ENDFILE
+# Invoke using gawk -f egrep.awk -- options ...
 
 BEGIN {
-    while ((c = getopt(ARGC, ARGV, "ce:svil")) != -1) {
+    while ((c = getopt(ARGC, ARGV, "ce:ilnqsvx")) != -1) {
         if (c == "c")
             count_only++
-        else if (c == "s")
-            no_print++
-        else if (c == "v")
-            invert++
+        else if (c == "e")
+            pattern = Optarg
         else if (c == "i")
             IGNORECASE = 1
         else if (c == "l")
             filenames_only++
-        else if (c == "e")
-            pattern = Optarg
+        else if (c == "n")
+            line_numbers++
+        else if (c == "q")
+            no_print++
+        else if (c == "s")
+            no_errors++
+        else if (c == "v")
+            invert++
+        else if (c == "x")
+            full_line++
         else
             usage()
     }
     if (pattern == "")
         pattern = ARGV[Optind++]
 
+    if (pattern == "")
+      usage()
+
     for (i = 1; i < Optind; i++)
         ARGV[i] = ""
+
     if (Optind >= ARGC) {
         ARGV[1] = "-"
         ARGC = 2
     } else if (ARGC - Optind > 1)
         do_filenames++
-
-#    if (IGNORECASE)
-#        pattern = tolower(pattern)
 }
-#{
-#    if (IGNORECASE)
-#        $0 = tolower($0)
-#}
-function beginfile(junk)
-{
+BEGINFILE {
     fcount = 0
+    if (ERRNO && no_errors)
+        nextfile
 }
-function endfile(file)
-{
+ENDFILE {
     if (! no_print && count_only) {
         if (do_filenames)
             print file ":" fcount
@@ -64,7 +73,10 @@ function endfile(file)
     total += fcount
 }
 {
-    matches = ($0 ~ pattern)
+    matches = match($0, pattern)
+    if (matches && full_line && (RSTART != 1 || RLENGTH != length()))
+         matches = 0
+
     if (invert)
         matches = ! matches
 
@@ -83,7 +95,10 @@ function endfile(file)
         }
 
         if (do_filenames)
-            print FILENAME ":" $0
+            if (line_numbers)
+               print FILENAME ":" FNR ":" $0
+            else
+               print FILENAME ":" $0
         else
             print
     }
@@ -93,7 +108,7 @@ END {
 }
 function usage()
 {
-    print("Usage: egrep [-csvil] [-e pat] [files ...]") > "/dev/stderr"
-    print("\n\tegrep [-csvil] pat [files ...]") > "/dev/stderr"
+    print("Usage:\tegrep [-cilnqsvx] [-e pat] [files ...]") > "/dev/stderr"
+    print("\tegrep [-cilnqsvx] pat [files ...]") > "/dev/stderr"
     exit 1
 }