[hackers] [sbase] Make grep more memory-efficient || FRIGN

From: <git_AT_suckless.org>
Date: Mon, 12 May 2014 01:32:57 +0200

commit fb1bfe24bb4ae08bdd56732244a74d89033dd130
Author: FRIGN <dev_AT_frign.de>
Date: Mon May 12 00:31:07 2014 +0200

    Make grep more memory-efficient

diff --git a/grep.c b/grep.c
index 269ec92..f6bbcc1 100644
--- a/grep.c
+++ b/grep.c
_AT_@ -11,7 +11,7 @@
 enum { Match = 0, NoMatch = 1, Error = 2 };
 
 static void addpattern(const char *);
-static bool grep(FILE *, const char *);
+static bool grep(FILE *, const char *, int);
 
 static bool eflag = false;
 static bool vflag = false;
_AT_@ -20,7 +20,6 @@ static char mode = 0;
 
 static struct plist {
         char *pattern;
- regex_t preg;
         struct plist *next;
 } *phead;
 
_AT_@ -35,7 +34,7 @@ main(int argc, char *argv[])
 {
         bool match = false;
         struct plist *pnode, *tmp;
- int i, n, flags = REG_NOSUB;
+ int i, flags = REG_NOSUB;
         FILE *fp;
 
         ARGBEGIN {
_AT_@ -62,8 +61,9 @@ main(int argc, char *argv[])
                 usage();
         } ARGEND;
 
+ /* no pattern */
         if(argc == 0 && !eflag)
- usage(); /* no pattern */
+ usage();
 
         /* If -e is not specified treat it as if it were */
         if(!eflag) {
_AT_@ -72,23 +72,14 @@ main(int argc, char *argv[])
                 argv++;
         }
 
- /* Compile regex for all search patterns */
- for(pnode = phead; pnode; pnode = pnode->next) {
- if((n = regcomp(&pnode->preg, pnode->pattern, flags)) != 0) {
- char buf[BUFSIZ];
-
- regerror(n, &pnode->preg, buf, sizeof buf);
- enprintf(Error, "invalid pattern: %s
", buf);
- }
- }
         many = (argc > 1);
         if(argc == 0) {
- match = grep(stdin, "<stdin>");
+ match = grep(stdin, "<stdin>", flags);
         } else {
                 for(i = 0; i < argc; i++) {
                         if(!(fp = fopen(argv[i], "r")))
                                 enprintf(Error, "fopen %s:", argv[i]);
- if(grep(fp, argv[i]))
+ if(grep(fp, argv[i], flags))
                                 match = true;
                         fclose(fp);
                 }
_AT_@ -96,7 +87,6 @@ main(int argc, char *argv[])
         pnode = phead;
         while(pnode) {
                 tmp = pnode->next;
- regfree(&pnode->preg);
                 free(pnode->pattern);
                 free(pnode);
                 pnode = tmp;
_AT_@ -120,20 +110,30 @@ addpattern(const char *pattern)
 }
 
 bool
-grep(FILE *fp, const char *str)
+grep(FILE *fp, const char *str, int flags)
 {
         char *buf = NULL;
         long n, c = 0;
+ int r;
+ static regex_t preg;
         size_t size = 0, len;
         struct plist *pnode;
         bool match = false;
 
         for(n = 1; afgets(&buf, &size, fp); n++) {
                 for(pnode = phead; pnode; pnode = pnode->next) {
+ if((r = regcomp(&preg, pnode->pattern, flags)) != 0) {
+ char err[BUFSIZ];
+
+ regerror(r, &preg, err, sizeof err);
+ enprintf(Error, "invalid pattern: %s
", err);
+ }
                         if(buf[(len = strlen(buf))-1] == '
')
                                 buf[--len] = '
Received on Mon May 12 2014 - 01:32:57 CEST