5 files changed, 144 insertions, 0 deletions
diff --git a/30_sort_lines/Makefile b/30_sort_lines/Makefile
new file mode 100644
index 0000000..28452a5
--- /dev/null
+++ b/30_sort_lines/Makefile
@@ -0,0 +1,6 @@
+CFLAGS=-ggdb3 -Wall -Werror -std=gnu99 -pedantic
+sortLines: sortLines.c
+        gcc $(CFLAGS) -o sortLines sortLines.c
+
+clean:
+        rm -f sortLines *~
diff --git a/30_sort_lines/README b/30_sort_lines/README
new file mode 100644
index 0000000..c5dcb2a
--- /dev/null
+++ b/30_sort_lines/README
@@ -0,0 +1,43 @@
+For this problem, you will write a program (by modifying the provided
+sortLines.c file) which sorts strings from input files. As we have not
+yet covered sorting, we have provided the code that does the acutal
+sorting.  You can just call this function, which will sort the data.
+
+  void sortData(char ** data, size_t count);
+
+The sortData function takes two arguments.  The first is an array of strings.
+The second is the length of that array.  It will re-order the elements of the
+array, such that they are sorted.
+
+Your task in this problem primarily centers around reading the data into
+the array from the input file(s), so that it can be sorted.  You will also
+need to print the data after it is sorted, and free all of the memory you have allocated.
+
+Specifically, this program should take 0 or more command line arguments.
+ - If no arguments (other than its own name) are provided (argc ==1), then 
+   your program should read from standard input, sort the lines of input,
+   print the results, free memory, and exit successfully.
+ - If 1 or more arguments are provided (argc > 1), then your program should
+   treat each argument as an input file name.  It should open that file,
+   read all of the lines of data in it, sort the lines, print the results,
+   free the memory, and close the file.  If any errors occur, your program
+   should print an appropriate error message and exit with EXIT_FAILURE.
+   If no errors occur, your program should indicate its success after processing
+   all of the files.
+
+Note that we now place *no* restriction on the length of any individual line of input.  
+You should therefore use the getline function to read an arbitrarily long line of 
+input, dynamically allocating space for it as needed.   See the man page for getline
+for more details. 
+
+You should make sure your program valgrinds cleanly, including no memory leaks
+before you submit it.  As always, submit your code for grading.
+
+We've provided one simple test for you to use to test your program. Run it with:
+./test.sh
+
+Hints:
+  - Don't forget to abstract code out into smaller function.  In my solution,
+    I wrote 3 functions other than main (plus the 2 that are provided).
+  - Don't forget to draw pictures!  They are even more important
+    as you use pointers more and more.
diff --git a/30_sort_lines/grade.txt b/30_sort_lines/grade.txt
new file mode 100644
index 0000000..19df8c9
--- /dev/null
+++ b/30_sort_lines/grade.txt
@@ -0,0 +1,24 @@
+Grading at Fri 17 Dec 2021 02:53:30 PM UTC
+Attempting to compile sortLines.c
+#################################################
+testcase1:
+testcase1 passed, your program successfully indicated a failure
+  - Valgrind was clean (no errors, no memory leaks)
+valgrind was clean
+#################################################
+testcase2:
+Your output is correct
+  - Valgrind was clean (no errors, no memory leaks)
+valgrind was clean
+#################################################
+testcase3:
+Your output is correct
+  - Valgrind was clean (no errors, no memory leaks)
+valgrind was clean
+#################################################
+testcase4:
+Your output is correct
+  - Valgrind was clean (no errors, no memory leaks)
+valgrind was clean
+
+Overall Grade: A
diff --git a/30_sort_lines/sortLines.c b/30_sort_lines/sortLines.c
new file mode 100644
index 0000000..3ef65ad
--- /dev/null
+++ b/30_sort_lines/sortLines.c
@@ -0,0 +1,70 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+//This function is used to figure out the ordering
+//of the strings in qsort.  You do not need
+//to modify it.
+int stringOrder(const void * vp1, const void * vp2) {
+  const char * const * p1 = vp1;
+  const char * const * p2 = vp2;
+  return strcmp(*p1, *p2);
+}
+//This function will sort and print data (whose length is count).
+void sortData(char ** data, size_t count) {
+  qsort(data, count, sizeof(char *), stringOrder);
+}
+
+void processFile(FILE * f) {
+  char ** lines = NULL;
+  char * curr = NULL;
+  size_t sz;
+  size_t i = 0;
+
+  //processing: building string array
+  while (getline(&curr, &sz, f) >= 0) {
+    lines = realloc(lines, (i+1) * sizeof(*lines));
+    lines[i] = curr;
+    curr = NULL;
+    i++;
+  }
+
+  //sorting
+  free(curr);
+  sortData(lines, i);
+
+  //printing then freeing each line
+  for (size_t j = 0; j < i; j++) {
+    printf("%s", lines[j]);
+    free(lines[j]);
+  }
+
+  //clean up
+  free(lines);
+}
+
+int main(int argc, char ** argv) {
+  
+  if (argc == 1) {
+    // stdin
+    processFile(stdin);
+  }
+  else {
+    for (int i = 1; i < argc; i++) {
+      // process each file one by one
+        FILE *f = fopen(argv[i], "r");
+        if (f == NULL) {
+            fprintf(stderr, "Could not open file\n");
+            return EXIT_FAILURE;
+        }
+        processFile(f);
+        if (fclose(f) != 0) {
+            fprintf(stderr, "Could not close file\n");
+            return EXIT_FAILURE;
+        }
+    }
+  }
+  
+  return EXIT_SUCCESS;
+}
diff --git a/30_sort_lines/test.sh b/30_sort_lines/test.sh
new file mode 100755
index 0000000..2d9b268
--- /dev/null
+++ b/30_sort_lines/test.sh
@@ -0,0 +1 @@
+printf "%s\n%s\n%s\n" "This is a sample test case" "it checks your program's one argument behavior" "go!" | tee | ./sortLines