Initial commit

10 files changed, 542 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..1b5de9a
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,20 @@
+BINS = ascii class depipe_strings dup fpipe realloc strpbrk strsep tokenizer
+CC = gcc
+DBGFLAGS = -g -O0
+ifdef DEBUG
+    CFLAGS = $(DBGFLAGS) -D DEBUG -std=gnu99 -Wall -pedantic
+else
+    CFLAGS = -O2 -std=gnu99 -Wall -pedantic
+endif
+LDFLAGS = -lm
+
+all: $(BINS)
+
+$(BINS): %: %.c
+	$(CC) $(CFLAGS) $^ -o $@ 
+
+
+.PHONY: clean
+
+clean:
+	rm -f ./$(BINS)
diff --git a/ascii.c b/ascii.c
new file mode 100644
index 0000000..eb24ba5
--- /dev/null
+++ b/ascii.c
@@ -0,0 +1,30 @@
+#include <stdio.h>
+
+int main(int argc, char *argv[])
+{
+    printf("\tASCII Table\n");
+
+    int i, j;
+
+    for (j = 0, i = 1; i < 128 + 1; i++)
+    {
+        if (!(j < 32) && j != 127)
+            printf("%3d %c", j, j);
+        else
+            printf("%3d  ", j);            
+
+        j += 32;
+         
+        if (i % 4 == 0)
+        {
+            j = (i / 4);
+            printf("\n");
+        }
+        else
+            printf("\t");
+    }
+    puts("");
+
+    return 0;
+}
+
diff --git a/class.c b/class.c
new file mode 100644
index 0000000..dda044a
--- /dev/null
+++ b/class.c
@@ -0,0 +1,53 @@
+#include <stdio.h>
+
+void printS(char *str)
+{
+    puts(str);
+}
+
+void printF(float *f)
+{
+    printf("%f\n", f);
+}
+
+struct GLFrame
+{
+    int x, y, z;
+    void (*func1)(char *);
+    void (*func2)(struct GLFrame *, int *, int *, int *);
+};
+
+void modPos(struct GLFrame *frame, int *x, int *y, int *z)
+{
+    frame->x = *x;
+    frame->y = *y;
+    frame->z = *z;
+}
+
+struct GLFrame frame = {
+    .x = 5,
+    .y = 6,
+    .z = 7,
+    .func1 = printS,
+    .func2 = modPos
+};
+
+int main(void)
+{
+#if 0
+    float x = 1.0f;
+    printf("x in hex: 0x%016x\n", x);
+#endif
+
+    int x, y, z;
+    x = y = z = 3;
+    /* i want to modify position vector, xyz */
+    frame.func2(&frame, &x, &y, &z);
+
+    printf("x is: %d\ny is: %d\nz is: %d\n", frame.x, frame.y, frame.z);
+
+    puts("Hello");
+
+    return 0;
+}
+
diff --git a/depipe_strings.c b/depipe_strings.c
new file mode 100644
index 0000000..597ade8
--- /dev/null
+++ b/depipe_strings.c
@@ -0,0 +1,89 @@
+/* depipe_strings.c
+ *
+ * Depipe apps into strings
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <wait.h>
+
+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 **depiped = depipe_string(line, &count);
+
+    int j;
+    for (j = 0; j < count; j++)
+        printf("app %d: %s\n", j+1, depiped[j]);
+
+    free(depiped);
+
+    return 0;
+}
+
+char **depipe_string(const char *line, int *count)
+{
+    char *last = (char *) line;
+    char *curr = NULL;
+
+    int i;
+    int num_apps = 10;
+    int fname = 100;
+    char **piped_apps = (char **) malloc(sizeof(char *) * num_apps);
+    piped_apps[0] = malloc(sizeof(char) * num_apps * fname);
+
+    /* construct m-dimensional array from 1 block of memory */
+    for (i = 1; i < num_apps; i++)
+        piped_apps[i] = piped_apps[0] + (i * fname);
+
+    *count = 0;
+    i = 0;
+    int j = 0;
+    size_t line_delta = 0;
+
+    while ( (curr = strchr(last, '|')) )
+    {
+        /* skip white space */
+        while (last[0] == ' ')
+            last++;
+
+        line_delta = curr - last;
+        strncpy(piped_apps[i], last, line_delta);
+        piped_apps[i][line_delta] = '\0';
+
+        /* delete whitespace at the tail */
+        j = line_delta - 1;
+        while (piped_apps[i][j] == ' ')
+            piped_apps[i][j--] = '\0';
+
+        last = curr + 1;
+        i++;
+    }
+
+    /* copy over last item */
+
+    /* skip white space */
+    while (last[0] == ' ')
+        last++;
+
+    line_delta = line + strlen(line) - (last-1);
+    strncpy(piped_apps[i], last, line_delta);
+    piped_apps[i][line_delta] = '\0';
+
+    /* delete whitespace at the tail */
+    j = strlen(piped_apps[i]) - 1;
+    while (piped_apps[i][j] == ' ')
+        piped_apps[i][j--] = '\0';
+
+    i++;
+
+    *count = i;
+    return piped_apps;
+}
+
diff --git a/dup.c b/dup.c
new file mode 100644
index 0000000..e70b804
--- /dev/null
+++ b/dup.c
@@ -0,0 +1,61 @@
+/* dup.c
+ *
+ * Child piping input to parent
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <wait.h>
+
+extern char **environ;
+
+int main(int argc, char **argv)
+{
+    pid_t pid;
+    int stat_loc;
+
+    int pfds[2];
+    int ret;
+
+    if (pipe(pfds) == 0)
+    {
+        pid = fork();
+        if (pid == -1)
+        {
+            perror("fork");
+            exit(EXIT_FAILURE);
+        }
+
+        if (!pid)
+        {
+            close(1);         /* break the link to stdout */
+            dup2(pfds[1], 1); /* redirect stdout to pfds[1] */
+            close(pfds[0]);   /* child will not be reading anything from out pipe */
+
+            execlp("ls", "ls", "-1", NULL);
+        }
+        else
+        {
+            close(0);         /* break the link to stdin */
+            dup2(pfds[0], 0); /* redirect stdout to pfds[0] */
+            close(pfds[1]);   /* parent will not be writing anything into our pipe */
+
+            ret = waitpid(pid, &stat_loc, WCONTINUED);
+            execlp("wc", "wc", "-l", NULL);
+        }
+    }
+    else
+    {
+        perror("pipe");
+        exit(EXIT_FAILURE);
+    }
+
+    close(pfds[0]);
+    close(pfds[1]);
+
+    return 0;
+}
+
diff --git a/fpipe.c b/fpipe.c
new file mode 100644
index 0000000..4ec9866
--- /dev/null
+++ b/fpipe.c
@@ -0,0 +1,59 @@
+/* fpipe.c
+ *
+ * Parent writing to child
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <wait.h>
+#define MAX_LINE 80
+
+int main(int argc, char **argv)
+{
+    pid_t pid;
+    int stat_loc;
+
+    int pfds[2];
+    int ret;
+
+    char buf[MAX_LINE+1];
+    const char *testbuf = { "I'm a parent and I'm writing to you" };
+
+    if (pipe(pfds) == 0)
+    {
+        pid = fork();
+        if (pid == -1)
+        {
+            perror("fork");
+            exit(EXIT_FAILURE);
+        }
+
+        if (!pid)
+        {
+            close(pfds[1]); /* child will not be writing anything */
+            ret = read(pfds[0], buf, MAX_LINE);
+            buf[ret] = 0;
+            printf("Child read: %s\n", buf);
+        }
+        else
+        {
+            close(pfds[0]); /* parent will not be reading anything */
+            ret = write(pfds[1], testbuf, strlen(testbuf));
+            ret = waitpid(pid, &stat_loc, WCONTINUED);
+        }
+    }
+    else
+    {
+        perror("pipe");
+        exit(EXIT_FAILURE);
+    }
+
+    close(pfds[0]);
+    close(pfds[1]);
+
+    return 0;
+}
+
diff --git a/realloc.c b/realloc.c
new file mode 100644
index 0000000..e9aec19
--- /dev/null
+++ b/realloc.c
@@ -0,0 +1,77 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct
+{
+    int length;
+    char *line;
+} sNode;
+
+struct String
+{
+    int index;
+    int size;
+    sNode *arr;
+};
+
+struct String *string_new(char *str);
+void string_append(struct String *a, char *b);
+void string_resize(struct String *s);
+
+struct String *string_new(char *str)
+{
+    struct String *ret = (struct String *) calloc(1, sizeof(struct String));
+    ret->arr = (sNode *) calloc(1, (sizeof(sNode) * 200));
+    ret->size = 200;
+    string_append(ret, str);
+
+    return ret;
+}
+
+void string_append(struct String *a, char *b)
+{
+    if ((a->size-1) == a->index)
+        string_resize(a);
+
+    a->arr[a->index].line = b;
+    a->arr[a->index].length = strlen(b);
+    
+    a->index++;
+}
+
+void string_resize(struct String *s)
+{
+    /* quadruple the size */
+    int newSize = s->size * 4;
+    printf("debug: resizing to new size of %d\n", newSize);
+
+    s->size = newSize;
+    sNode *newarr = (sNode *) realloc(s->arr, (sizeof(sNode) * newSize));
+    if (!newarr)
+    {
+        perror("realloc");
+        exit(-1);
+    }
+
+    /* free old array */
+    free(s->arr);
+    s->arr = newarr;
+
+}
+
+int main(int argc, char **argv)
+{
+    if (argc < 2)
+    {
+        fprintf(stderr,"Usage: app n\n");
+        exit(1);
+    }
+
+    struct String *str = string_new("");
+
+    int i;
+    for (i = 0; i < atoi(argv[1]); i++)
+        string_append(str, "anything that can go wrong, will");
+}
+
diff --git a/strpbrk.c b/strpbrk.c
new file mode 100644
index 0000000..4d614d7
--- /dev/null
+++ b/strpbrk.c
@@ -0,0 +1,81 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+char **redir_chop(const char *line)
+{
+    if (!line)
+        return NULL;
+
+    const char *redir_delim = "><";
+
+    char *pipe_redir = strpbrk(line, redir_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);
+
+    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);
+
+    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);
+ 
+    printf("former string: \"%s\"\n", chopped[0]);
+    printf("latter string: \"%s\"\n", chopped[1]);   
+    
+    return 0;
+}
+
diff --git a/strsep.c b/strsep.c
new file mode 100644
index 0000000..882a1e0
--- /dev/null
+++ b/strsep.c
@@ -0,0 +1,39 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main(int argc, char **argv)
+{
+    char *line = "ls -1 | wc -l | less";
+
+    size_t sz = strlen(line) + 1;
+    char *linecopy = malloc(sizeof(char) * sz);
+    strcpy(linecopy, line);
+    linecopy[sz-1] = '\0';
+
+    char *args[10];
+    char **lineptr = &linecopy;
+
+    char *tok = NULL;
+    const char arg_delim = ' ';
+    int i = 0;
+
+    do
+    {
+        tok = strsep(lineptr, &arg_delim);
+        args[i] = tok;
+        i++;
+    }
+    while ((tok != NULL) && (i < 9));
+    
+    if (i == 10)
+        args[9] = NULL;
+
+    /* print out the piped string */
+    int j;    
+    for (j = 0; j < i; j++)
+        printf("string argument %d: \"%s\"\n", j, args[j]);
+
+    return 0;
+}
+
diff --git a/tokenizer.c b/tokenizer.c
new file mode 100644
index 0000000..461383a
--- /dev/null
+++ b/tokenizer.c
@@ -0,0 +1,33 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main(int argc, char *argv[])
+{
+   char *str1, *str2, *token, *subtoken;
+   char *saveptr1, *saveptr2;
+   int j;
+
+   if (argc != 4) {
+       fprintf(stderr, "Usage: %s string delim subdelim\n",
+               argv[0]);
+       exit(EXIT_FAILURE);
+   }
+
+   for (j = 1, str1 = argv[1]; ; j++, str1 = NULL) {
+       token = strtok_r(str1, argv[2], &saveptr1);
+       if (token == NULL)
+           break;
+       printf("%d: %s\n", j, token);
+
+       for (str2 = token; ; str2 = NULL) {
+           subtoken = strtok_r(str2, argv[3], &saveptr2);
+           if (subtoken == NULL)
+               break;
+           printf(" --> %s\n", subtoken);
+       }
+   }
+
+   exit(EXIT_SUCCESS);
+}
+