From cc9d6f352698e9f1eb59e00a6068feef272c0006 Mon Sep 17 00:00:00 2001
From: "Begerad, Stefan" <dialog@swingbe.de>
Date: Fri, 20 Jan 2023 11:44:46 +0100
Subject: [PATCH] feat: file2char

---
 file2char/main.c    | 119 ++++++++++++++++++++++++++++++++++++++++++++
 file2char/makefile  |  19 +++++++
 file2char/readme.md |  23 +++++++++
 3 files changed, 161 insertions(+)
 create mode 100644 file2char/main.c
 create mode 100644 file2char/makefile
 create mode 100644 file2char/readme.md

diff --git a/file2char/main.c b/file2char/main.c
new file mode 100644
index 0000000..8f7bb31
--- /dev/null
+++ b/file2char/main.c
@@ -0,0 +1,119 @@
+/*to use exit*/
+#include <stdlib.h>
+/*to use *print**/
+#include <stdio.h>
+
+/*
+ * load_file reads the file identified by 'path' into a character buffer
+ * pointed at by 'buf'.
+ * On success, the size of the file is returned.
+ * On failure, exit(EXIT_FAILURE) is returned and.
+ *
+ * WARNING: load_file malloc()s memory to '*buf' which must be freed by
+ * the caller.
+ */
+int load_file(char const* path, char **buf){
+  /*declarations*/
+  FILE *fp;
+  long lSize;
+
+  /*fopen()
+   *filename
+   *mode
+   *return: set errno value in error case
+   */
+  fp=fopen(path,"r");
+
+  if(fp){
+    fprintf(stdout,"file opened.\n");
+
+    /*set offset to file end*/
+    /*fseek()
+     *stream
+     *offset
+     *origin
+     */
+    fseek(fp,0L,SEEK_END);
+    if (ferror(fp)){
+      printf ("Error seeking file\n");
+    }
+
+    /*get file size*/
+    lSize = ftell( fp );
+    fprintf(stdout,"lSize: %ld.\n",lSize);
+
+    /*set offset to file start*/
+    fseek(fp,0,SEEK_SET);
+    if (ferror(fp)){
+      printf ("Error seeking file\n");
+    }
+
+    /*allocate memory for entire content + null termination*/
+    *buf=(char *)malloc((lSize+1)*sizeof(char));
+    if(!*buf){
+      fclose(fp);
+      fputs("Error allocating memory",stderr);
+      exit(EXIT_FAILURE);
+    }
+    fprintf(stdout,"mem allocated.\n");
+
+    /*copy file into buffer*/
+    /*fread()
+     *ptr
+     *size
+     *count
+     *stream
+     */
+    if( 1!=fread(*buf,lSize,1,fp)){
+      fclose(fp);
+      free(*buf);
+      fputs("Error reading entire file",stderr);
+      exit(EXIT_FAILURE);
+    }
+    fprintf(stdout,"file read.\n");
+
+    /*close file*/
+    if(EOF==fclose(fp)){
+      free(*buf);
+      exit(EXIT_FAILURE);
+    }
+    fprintf(stdout,"file closed.\n");
+
+    (*buf)[lSize] = '\0';
+    fprintf(stdout,"mem null terminated.\n");
+
+    /*TODO Cleanup debugging!*/
+    /*
+    for (int i = 0; i < lSize; i++) {
+       printf("buffer[%d] == %c\n", i, buffer[i]);
+    }
+    */
+    printf("buffer = %s\n", *buf);
+    
+  }else{
+    perror(path);
+    exit(EXIT_FAILURE);
+  }
+  /*done*/
+  return lSize;
+}
+
+int main(int argc, char** argv){
+  /*declaration*/
+  int  fileSize;
+  char *buf;
+
+  fprintf(stdout,"main() Started...\n");
+
+  if (argc != 2) {
+    fprintf(stderr, "Usage: %s <file path>\n", argv[0]);
+    exit(EXIT_FAILURE);
+  }
+
+  
+  fileSize = load_file(argv[1], &buf);
+  free(buf);
+  fprintf(stdout,"main() fileSize: %d.\n",fileSize);
+  fprintf(stdout,"main() Done.\n");
+  return 0;
+}
diff --git a/file2char/makefile b/file2char/makefile
new file mode 100644
index 0000000..bcd60d7
--- /dev/null
+++ b/file2char/makefile
@@ -0,0 +1,19 @@
+#target: dependency_1 dependency_2 dependency_3 ...
+#	command
+#
+RM = /bin/rm -f
+OBJ = main.o
+EXE = main
+CC = /usr/bin/gcc
+CFLAGS = -Wall
+#
+all: $(EXE)
+#
+$(EXE): $(OBJ)
+	$(CC) $(CFLAGS) $(OBJ) -o $(EXE)
+#
+main.o: main.c
+	$(CC) -c main.c -o main.o
+#
+clean:
+	$(RM) $(OBJ) $(EXE) *~
diff --git a/file2char/readme.md b/file2char/readme.md
new file mode 100644
index 0000000..ac2cb44
--- /dev/null
+++ b/file2char/readme.md
@@ -0,0 +1,23 @@
+* build
+
+```
+make clean all
+```
+
+* cleanup
+
+```
+make clean
+```
+
+* run
+
+```
+./main <file path>
+```
+
+* run Valgrind tool `Memcheck`
+
+```
+valgrind --leak-check=yes -s ./main <file path>
+```