read_file.c

@@ -0,0 +1,130 @@
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef char *string;
+
+/**
+ * TODO
+ */
+string *read_file(const string pathname)
+{
+    // Open file
+    FILE *file = fopen(pathname, "r");
+    if (file == NULL)
+    {
+        return NULL;
+    }
+
+    // Allocate space for NULL-terminated array of lines
+    string *lines = malloc(sizeof(string *));
+    if (lines == NULL)
+    {
+        return NULL;
+    }
+    lines[0] = NULL;
+    size_t size = 1;
+
+    // Read chars
+    long start = 0, end = 0;
+    while (true)
+    {
+        // Read char
+        int c = fgetc(file);
+
+        // Check for line ending
+        if (c == EOF || c == '\r' || c == '\n')
+        {
+            // If we've read a line with at least one char
+            if (start != end)
+            {
+                // Allocate space for line
+                string line = malloc(end - start + 1);
+                if (line == NULL)
+                {
+                    // TODO
+                    return NULL;
+                }
+
+                // Read string
+                if (fseek(file, start, SEEK_SET) == -1 || fread(line, end - start, 1, file) != 1)
+                {
+                    // TODO
+                    return NULL;
+                }
+
+                // Terminate string
+                line[end - start] = '\0';
+
+                // Extend array
+                if (size == SIZE_MAX)
+                {
+                    // TODO
+                    return NULL;
+                }
+                string *temp = realloc(lines, ++size);
+                if (temp == NULL)
+                {
+                    // TODO
+                    return NULL;
+                }
+                temp[size - 2] = line;
+                temp[size - 1] = NULL;
+                lines = temp;
+
+                // Start of next line, if any
+                start = end = end + 1;
+
+                // Check for CR
+                if (c == '\r')
+                {
+                    // Check for LF
+                    int d = fgetc(file);
+                    if (d == '\n')
+                    {
+                        // Ignore LF
+                        start = end = end + 1;
+                    }
+                    else if (d != EOF)
+                    {
+                        // Unget char
+                        if (ungetc(d, file) == EOF)
+                        {
+                            // TODO
+                        }
+                    }
+                }
+            }
+
+            // End of file
+            if (c == EOF)
+            {
+                break;
+            }
+        }
+
+        // Not at end of file or line
+        else
+        {
+            end++;
+        }
+    }
+
+    // Return array of lines
+    return lines;
+}
+
+int main(void)
+{
+    string *lines = read_file("read_file.txt");
+    if (lines == NULL)
+    {
+        printf("ERROR\n");
+        exit(1);
+    }
+    for (int i = 0; lines[i] != NULL; i++)
+    {
+        printf("%s\n", lines[i]);
+    }
+}

read_file.txt

@@ -0,0 +1 @@
+foobarbaz