[hackers] [sbase] Implement grep -x || sin

[git]

commit 7627a5069cb14c66d8ba964e4a02ce5b56ff6180
Author: sin <s...@2f30.org>
Date:   Thu Nov 20 14:47:26 2014 +0000

    Implement grep -x

diff --git a/grep.1 b/grep.1
index 7eef257..b939f7c 100644
--- a/grep.1
+++ b/grep.1
@@ -3,7 +3,7 @@
 grep \- search files for a pattern
 .SH SYNOPSIS
 .B grep
-.RB [ \-EFHchilnqsv ]
+.RB [ \-EFHchilnqsvx ]
 .RB [ \-e
 .I pattern ]
 .I pattern
@@ -64,5 +64,9 @@ Suppress the error messages ordinarily written for 
nonexistent or unreadable fil
 Selects lines which do
 .B not
 Match the pattern.
+.TP
+.B \-x
+Consider only input lines that use all characters in the line excluding the 
terminating <newline> to
+match an entire fixed string or regular expression to be matching lines.
 .SH SEE ALSO
 .IR regex (7)
diff --git a/grep.c b/grep.c
index 3dbf9b8..153f8f7 100644
--- a/grep.c
+++ b/grep.c
@@ -20,6 +20,7 @@ static int eflag;
 static int hflag;
 static int sflag;
 static int vflag;
+static int xflag;
 static int many;
 static char mode;
 
@@ -34,7 +35,7 @@ static SLIST_HEAD(phead, pattern) phead;
 static void
 usage(void)
 {
-       enprintf(Error, "usage: %s [-EFHcilnqsv] [-e pattern] pattern 
[files...]\n", argv0);
+       enprintf(Error, "usage: %s [-EFHcilnqsvx] [-e pattern] pattern 
[files...]\n", argv0);
 }
 
 int
@@ -78,6 +79,9 @@ main(int argc, char *argv[])
        case 'v':
                vflag = 1;
                break;
+       case 'x':
+               xflag = 1;
+               break;
        default:
                usage();
        } ARGEND;
@@ -128,9 +132,19 @@ static void
 addpattern(const char *pattern)
 {
        struct pattern *pnode;
+       char *tmp;
 
        pnode = emalloc(sizeof(*pnode));
-       pnode->pattern = estrdup(pattern);
+       if (!Fflag && xflag) {
+               tmp = emalloc(strlen(pattern) + 3);
+               snprintf(tmp, strlen(pattern) + 3, "%s%s%s",
+                        pattern[0] == '^' ? "" : "^",
+                        pattern,
+                        pattern[strlen(pattern) - 1] == '$' ? "" : "$");
+               pnode->pattern = tmp;
+       } else {
+               pnode->pattern = estrdup(pattern);
+       }
        SLIST_INSERT_HEAD(&phead, pnode, entry);
 }
 
@@ -152,7 +166,10 @@ grep(FILE *fp, const char *str)
                                if (regexec(&pnode->preg, buf, 0, NULL, 0) ^ 
vflag)
                                        continue;
                        } else {
-                               match = strstr(buf, pnode->pattern) ? Match : 
NoMatch;
+                               if (!xflag)
+                                       match = strstr(buf, pnode->pattern) ? 
Match : NoMatch;
+                               else
+                                       match = strcmp(buf, pnode->pattern);
                                if (match ^ vflag)
                                        continue;
                        }