cleanups

4 files changed, 59 insertions, 43 deletions

diff --git a/Makefile b/Makefile
index 1b5de9a..273a07b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-BINS = ascii class depipe_strings dup fpipe realloc strpbrk strsep tokenizer
+BINS = ascii class depipe_strings dup fpipe pipe realloc strpbrk strsep tokenizer
 CC = gcc
 DBGFLAGS = -g -O0
 ifdef DEBUG
diff --git a/depipe_strings.c b/depipe_strings.c
index 597ade8..61115d7 100644
--- a/depipe_strings.c
+++ b/depipe_strings.c
@@ -15,7 +15,7 @@ char **depipe_string(const char *, int *);
 int main(int argc, char **argv)
 {
     int count;
-    char *line = "   ls -1      |   wc -l | cut -n1 |      less | rtfm|           bro       ";
+    char *line = "   ls -1      |   wc -l | cut -b 6-7";
     char **depiped = depipe_string(line, &count);
 
     int j;
@@ -27,6 +27,7 @@ int main(int argc, char **argv)
     return 0;
 }
 
+/* chops and counts strings with arguments that are separated by pipes */
 char **depipe_string(const char *line, int *count)
 {
     char *last = (char *) line;
diff --git a/pipe.c b/pipe.c
new file mode 100644
index 0000000..a5c86cc
--- /dev/null
+++ b/pipe.c
@@ -0,0 +1,40 @@
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define MAX_LINE    80
+#define PIPE_STDIN  0
+#define PIPE_STDOUT 1
+
+int main(int argc, char **argv)
+{
+    const char *string = {"A sample message."};
+    int ret, myPipe[2];
+    char buffer[MAX_LINE+1];
+
+    /* create the pipe */
+    ret = pipe(myPipe);
+
+    if (ret == 0)
+    {
+        /* write message into the pipe */
+        write(myPipe[PIPE_STDOUT], string, strlen(string));
+
+        /* read the message from the pipe */
+        ret = read(myPipe[PIPE_STDIN], buffer, MAX_LINE);
+
+        /* null terminate the string */
+        buffer[ret] = 0;
+
+        printf("%s\n", buffer);
+    }
+    else
+    {
+        perror("pipe");
+        exit(EXIT_FAILURE);
+    }
+
+    return 0;
+}
+
diff --git a/strpbrk.c b/strpbrk.c
index 4d614d7..a292a6e 100644
--- a/strpbrk.c
+++ b/strpbrk.c
@@ -2,20 +2,27 @@
 #include <stdlib.h>
 #include <string.h>
 
-char **redir_chop(const char *line)
+char **redir_chop(const char *, const char);
+
+/* chops a line into 2 string that are seperated by redir_delim  */
+char **redir_chop(const char *line, const char redir_delim)
 {
     if (!line)
         return NULL;
 
-    const char *redir_delim = "><";
+    const char *delim = &redir_delim;
 
-    char *pipe_redir = strpbrk(line, redir_delim);
+    char *pipe_redir = strpbrk(line, delim);
     if (pipe_redir == NULL)
         return NULL;
 
     size_t redir_delta = pipe_redir - line;
-    char *former = (char *) malloc(sizeof(char) * 100);
-    char *latter = (char *) malloc(sizeof(char) * 100);
+    char **ret = (char **) malloc(sizeof(char *) * 2);
+    ret[0] = (char *) malloc(sizeof(char) * 256 * 2);
+    ret[1] = ret[0] + 256;
+
+    char *former = ret[0];
+    char *latter = ret[1];
 
     strncpy(former, line, redir_delta);
     former[redir_delta] ='\0';
@@ -31,50 +38,18 @@ char **redir_chop(const char *line)
         ;
     strncpy(latter, line+j, (line + strlen(line)) - pipe_redir);
 
-    char **ret = (char **) malloc(sizeof(char *) * 2);
-    ret[0] = (char *) former;
-    ret[1] = (char *) latter;
-
     return ret;
 }
 
 int main(int argc, char *argv[])
 {
     const char *line = "ls -1 -al > filename.txt";
-
-#if 0
-    const char *redir_delim = "><";
-
-    char *pipe_redir = strpbrk(line, redir_delim);
-    size_t redir_delta = pipe_redir - line;
-    char *former = (char *) malloc(sizeof(char) * 100);
-    char *latter = (char *) malloc(sizeof(char) * 100);
-
-    strncpy(former, line, redir_delta);
-    former[redir_delta] ='\0';
-
-    /* delete spaces at the end of former string */
-    int i = strlen(former) - 1;
-    while (former[i] == ' ')
-        former[i--] = '\0';
-
-    /* skip spaces in latter string and then copy over */
-    int j = redir_delta;
-    while (line[++j] == ' ')
-        ;
-    strncpy(latter, line+j, (line + strlen(line)) - pipe_redir);
-
-    printf("former string: \"%s\"\n", former);
-    printf("latter string: \"%s\"\n", latter);
-
-    free(former);
-    free(latter);
-#endif
-
-    char **chopped = redir_chop(line);
+    char **chopped = redir_chop(line, '>');
  
     printf("former string: \"%s\"\n", chopped[0]);
-    printf("latter string: \"%s\"\n", chopped[1]);   
+    printf("latter string: \"%s\"\n", chopped[1]);
+
+    free(chopped);
     
     return 0;
 }