Cummulative work

7 files changed, 925 insertions, 80 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index efefe50..a130cda 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,11 @@
 cmake_minimum_required(VERSION 3.15)
 project(spm C)
+include(CheckSymbolExists)
 
 set(CMAKE_C_STANDARD 99)
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+check_symbol_exists(strsep string.h HAVE_STRSEP)
+configure_file(config.h.in config.h)
 
-add_executable(spm spm.c)
\ No newline at end of file
+add_executable(spm spm.c config.c spm.h config.h.in compat.c)
+target_link_libraries(spm rt)
diff --git a/compat.c b/compat.c
new file mode 100644
index 0000000..082a602
--- /dev/null
+++ b/compat.c
@@ -0,0 +1,16 @@
+#include <string.h>
+#include "config.h"
+
+#ifndef HAVE_STRSEP
+// credit: Dan Cross via https://unixpapa.com/incnote/string.html
+char *strsep(char **sp, char *sep)
+{
+    char *p, *s;
+    if (sp == NULL || *sp == NULL || **sp == '\0') return(NULL);
+    s = *sp;
+    p = s + strcspn(s, sep);
+    if (*p != '\0') *p++ = '\0';
+    *sp = p;
+    return(s);
+}
+#endif
\ No newline at end of file
diff --git a/config.c b/config.c
new file mode 100644
index 0000000..c2d905b
--- /dev/null
+++ b/config.c
@@ -0,0 +1,186 @@
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include "spm.h"
+
+
+/// Remove leading whitespace from a string
+/// \param sptr pointer to string
+/// \return pointer to first non-whitespace character in string
+char *lstrip(char *sptr) {
+    while (isblank(*sptr)) {
+        sptr++;
+    }
+    return sptr;
+}
+
+/// Remove trailing whitespace from a string
+/// \param sptr pointer to string
+/// \return truncated string
+char *strip(char *sptr) {
+    char *tmp = sptr + strlen(sptr) - 1;
+    while (isblank(*tmp) || *tmp == '\n') {
+        *tmp = '\0';
+        tmp--;
+    }
+    return sptr;
+}
+
+/// Determine if a string is empty
+/// \param sptr pointer to string
+/// \return 0=not empty, 1=empty
+int isempty(char *sptr) {
+    char *tmp = sptr;
+    while (*tmp) {
+        if (!isblank(*tmp)) {
+            return 0;
+        }
+        tmp++;
+    }
+    return 1;
+}
+
+/// Determine if a string is encapsulated by quotes
+/// \param sptr pointer to string
+/// \return 0=not quoted, 1=quoted
+int isquoted(char *sptr) {
+    const char *quotes = "'\"";
+    char *quote_open = strpbrk(sptr, quotes);
+    if (!quote_open) {
+        return 0;
+    }
+    char *quote_close = strpbrk(quote_open + 1, quotes);
+    if (!quote_close) {
+        return 0;
+    }
+    return 1;
+}
+
+Config **config_read(const char *filename) {
+    const char sep = '=';
+    char line[CONFIG_BUFFER_SIZE];
+    FILE *fp = fopen(filename, "r");
+    if (!fp) {
+        // errno will be set, so die, and let the caller handle it
+        return NULL;
+    }
+    int record_initial = 2;
+    Config **config = (Config **) calloc(record_initial, sizeof(Config *));
+    int record = 0;
+
+
+    while (fgets(line, sizeof(line), fp) != NULL) {
+        char *lptr = line;
+        // Remove leading space and newlines
+        lptr = lstrip(lptr);
+        // Remove trailing space and newlines
+        lptr = strip(lptr);
+
+        // Skip empty lines
+        if (isempty(lptr)) {
+            continue;
+        }
+        // Skip comment-only lines
+        if (*lptr == '#' || *lptr == ';') {
+            continue;
+        }
+
+        // Get a pointer to the key pair separator
+        char *sep_pos = strchr(lptr, sep);
+        if (!sep_pos) {
+            printf("invalid entry on line %d: missing '%c': '%s'\n", record, sep, lptr);
+            continue;
+        }
+
+        // Calculate key and value lengths dynamically
+        size_t key_length = strcspn(lptr, &sep);
+        size_t value_length = strlen(sep_pos);
+
+        // Allocate a Config record
+        config[record] = (Config *)calloc(1, sizeof(Config));
+        config[record]->key = (char *)calloc(key_length + 1, sizeof(char));
+        config[record]->value = (char *)calloc(value_length + 1, sizeof(char));
+
+        // Shortcut our array at this point. Things get pretty ugly otherwise.
+        char *key = config[record]->key;
+        char *value = config[record]->value;
+
+        // Populate the key and remove any trailing space
+        while (lptr != sep_pos) {
+            *key++ = *lptr++;
+        }
+        key = strip(key);
+
+        // We're at the separator now, so skip over it
+        lptr++;
+        // and remove any leading space
+        lptr = lstrip(lptr);
+
+        // Determine whether the string is surrounded by quotes, if so, get rid of them
+        if (isquoted(lptr)) {
+            // Move pointer beyond quote
+            lptr = strpbrk(lptr, "'\"") + 1;
+            // Terminate on closing quote
+            char *tmp = strpbrk(lptr, "'\"");
+            *tmp = '\0';
+        }
+
+        // Populate the value, and ignore any inline comments
+        while (*lptr) {
+            if (*lptr == '#' || *lptr == ';') {
+                // strip trailing whitespace where the comment is and stop processing
+                value = strip(value);
+                break;
+            }
+            *value++ = *lptr++;
+        }
+
+        // increment record count
+        record++;
+        // Expand config by another record
+        config = (Config **)reallocarray(config, record + record_initial + 1, sizeof(Config *));
+    }
+    return config;
+}
+
+void config_free(Config **config) {
+    for (int i = 0; config[i] != NULL; i++) {
+        free(config[i]);
+    }
+    free(config);
+}
+
+/// If the configuration contains `key` return a pointer to that record
+/// \param config pointer to array of config records
+/// \param key search for key in config records
+/// \return success=pointer to record, failure=NULL
+Config *config_get(Config **config, const char *key) {
+    for (int i = 0; config[i] != NULL; i++) {
+        if (!strcmp(config[i]->key, key)) {
+            return config[i];
+        }
+    }
+    return NULL;
+}
+
+void config_test(void) {
+    Config **config = config_read("program.conf");
+    printf("Data Parsed:\n");
+    for (int i = 0; config[i] != NULL; i++) {
+        printf("key: '%s', value: '%s'\n", config[i]->key, config[i]->value);
+    }
+
+    printf("Testing config_get():\n");
+    Config *cptr = NULL;
+    if ((cptr = config_get(config, "integer_value"))) {
+        printf("%s = %d\n", cptr->key, atoi(cptr->value));
+    }
+    if ((cptr = config_get(config, "float_value"))) {
+        printf("%s = %.3f\n", cptr->key, atof(cptr->value));
+    }
+    if ((cptr = config_get(config, "string_value"))) {
+        printf("%s = %s\n", cptr->key, cptr->value);
+    }
+    config_free(config);
+}
diff --git a/config.h.in b/config.h.in
new file mode 100644
index 0000000..cedd8a4
--- /dev/null
+++ b/config.h.in
@@ -0,0 +1,6 @@
+#ifndef SPM_CONFIG_IN_H
+#define SPM_CONFIG_IN_H
+
+#cmakedefine HAVE_STRSEP 1
+
+#endif //SPM_CONFIG_IN_H
diff --git a/doxygen.conf b/doxygen.conf
new file mode 100644
index 0000000..e535d50
--- /dev/null
+++ b/doxygen.conf
@@ -0,0 +1,379 @@
+# Doxyfile 1.8.16
+
+#---------------------------------------------------------------------------
+# Project related configuration options
+#---------------------------------------------------------------------------
+DOXYFILE_ENCODING      = UTF-8
+PROJECT_NAME           = "Simple Package Manager"
+PROJECT_NUMBER         = ${VERSION}
+PROJECT_BRIEF          = "a.k.a. SPM"
+PROJECT_LOGO           =
+OUTPUT_DIRECTORY       = /home/jhunk/CLionProjects/spm/docs
+CREATE_SUBDIRS         = NO
+ALLOW_UNICODE_NAMES    = NO
+OUTPUT_LANGUAGE        = English
+OUTPUT_TEXT_DIRECTION  = None
+BRIEF_MEMBER_DESC      = YES
+REPEAT_BRIEF           = YES
+ABBREVIATE_BRIEF       = "The $name class" \
+                         "The $name widget" \
+                         "The $name file" \
+                         is \
+                         provides \
+                         specifies \
+                         contains \
+                         represents \
+                         a \
+                         an \
+                         the
+ALWAYS_DETAILED_SEC    = NO
+INLINE_INHERITED_MEMB  = NO
+FULL_PATH_NAMES        = YES
+STRIP_FROM_PATH        =
+STRIP_FROM_INC_PATH    =
+SHORT_NAMES            = NO
+JAVADOC_AUTOBRIEF      = NO
+JAVADOC_BANNER         = NO
+QT_AUTOBRIEF           = NO
+MULTILINE_CPP_IS_BRIEF = NO
+INHERIT_DOCS           = YES
+SEPARATE_MEMBER_PAGES  = NO
+TAB_SIZE               = 4
+ALIASES                =
+TCL_SUBST              =
+OPTIMIZE_OUTPUT_FOR_C  = YES
+OPTIMIZE_OUTPUT_JAVA   = NO
+OPTIMIZE_FOR_FORTRAN   = NO
+OPTIMIZE_OUTPUT_VHDL   = NO
+OPTIMIZE_OUTPUT_SLICE  = NO
+EXTENSION_MAPPING      =
+MARKDOWN_SUPPORT       = YES
+TOC_INCLUDE_HEADINGS   = 5
+AUTOLINK_SUPPORT       = YES
+BUILTIN_STL_SUPPORT    = NO
+CPP_CLI_SUPPORT        = NO
+SIP_SUPPORT            = NO
+IDL_PROPERTY_SUPPORT   = YES
+DISTRIBUTE_GROUP_DOC   = NO
+GROUP_NESTED_COMPOUNDS = NO
+SUBGROUPING            = YES
+INLINE_GROUPED_CLASSES = NO
+INLINE_SIMPLE_STRUCTS  = NO
+TYPEDEF_HIDES_STRUCT   = NO
+LOOKUP_CACHE_SIZE      = 0
+#---------------------------------------------------------------------------
+# Build related configuration options
+#---------------------------------------------------------------------------
+EXTRACT_ALL            = NO
+EXTRACT_PRIVATE        = NO
+EXTRACT_PRIV_VIRTUAL   = NO
+EXTRACT_PACKAGE        = NO
+EXTRACT_STATIC         = NO
+EXTRACT_LOCAL_CLASSES  = YES
+EXTRACT_LOCAL_METHODS  = NO
+EXTRACT_ANON_NSPACES   = NO
+HIDE_UNDOC_MEMBERS     = NO
+HIDE_UNDOC_CLASSES     = NO
+HIDE_FRIEND_COMPOUNDS  = NO
+HIDE_IN_BODY_DOCS      = NO
+INTERNAL_DOCS          = NO
+CASE_SENSE_NAMES       = NO
+HIDE_SCOPE_NAMES       = YES
+HIDE_COMPOUND_REFERENCE= NO
+SHOW_INCLUDE_FILES     = YES
+SHOW_GROUPED_MEMB_INC  = NO
+FORCE_LOCAL_INCLUDES   = NO
+INLINE_INFO            = YES
+SORT_MEMBER_DOCS       = YES
+SORT_BRIEF_DOCS        = NO
+SORT_MEMBERS_CTORS_1ST = NO
+SORT_GROUP_NAMES       = NO
+SORT_BY_SCOPE_NAME     = NO
+STRICT_PROTO_MATCHING  = NO
+GENERATE_TODOLIST      = YES
+GENERATE_TESTLIST      = YES
+GENERATE_BUGLIST       = YES
+GENERATE_DEPRECATEDLIST= YES
+ENABLED_SECTIONS       =
+MAX_INITIALIZER_LINES  = 30
+SHOW_USED_FILES        = YES
+SHOW_FILES             = YES
+SHOW_NAMESPACES        = YES
+FILE_VERSION_FILTER    =
+LAYOUT_FILE            =
+CITE_BIB_FILES         =
+#---------------------------------------------------------------------------
+# Configuration options related to warning and progress messages
+#---------------------------------------------------------------------------
+QUIET                  = NO
+WARNINGS               = YES
+WARN_IF_UNDOCUMENTED   = YES
+WARN_IF_DOC_ERROR      = YES
+WARN_NO_PARAMDOC       = NO
+WARN_AS_ERROR          = NO
+WARN_FORMAT            = "$file:$line: $text"
+WARN_LOGFILE           =
+#---------------------------------------------------------------------------
+# Configuration options related to the input files
+#---------------------------------------------------------------------------
+INPUT                  = .
+INPUT_ENCODING         = UTF-8
+FILE_PATTERNS          = *.c \
+                         *.cc \
+                         *.cxx \
+                         *.cpp \
+                         *.c++ \
+                         *.java \
+                         *.ii \
+                         *.ixx \
+                         *.ipp \
+                         *.i++ \
+                         *.inl \
+                         *.idl \
+                         *.ddl \
+                         *.odl \
+                         *.h \
+                         *.hh \
+                         *.hxx \
+                         *.hpp \
+                         *.h++ \
+                         *.cs \
+                         *.d \
+                         *.php \
+                         *.php4 \
+                         *.php5 \
+                         *.phtml \
+                         *.inc \
+                         *.m \
+                         *.markdown \
+                         *.md \
+                         *.mm \
+                         *.dox \
+                         *.py \
+                         *.pyw \
+                         *.f90 \
+                         *.f95 \
+                         *.f03 \
+                         *.f08 \
+                         *.f \
+                         *.for \
+                         *.tcl \
+                         *.vhd \
+                         *.vhdl \
+                         *.ucf \
+                         *.qsf \
+                         *.ice
+RECURSIVE              = NO
+EXCLUDE                =
+EXCLUDE_SYMLINKS       = NO
+EXCLUDE_PATTERNS       =
+EXCLUDE_SYMBOLS        =
+EXAMPLE_PATH           =
+EXAMPLE_PATTERNS       = *
+EXAMPLE_RECURSIVE      = NO
+IMAGE_PATH             =
+INPUT_FILTER           =
+FILTER_PATTERNS        =
+FILTER_SOURCE_FILES    = NO
+FILTER_SOURCE_PATTERNS =
+USE_MDFILE_AS_MAINPAGE =
+#---------------------------------------------------------------------------
+# Configuration options related to source browsing
+#---------------------------------------------------------------------------
+SOURCE_BROWSER         = NO
+INLINE_SOURCES         = NO
+STRIP_CODE_COMMENTS    = YES
+REFERENCED_BY_RELATION = NO
+REFERENCES_RELATION    = NO
+REFERENCES_LINK_SOURCE = YES
+SOURCE_TOOLTIPS        = YES
+USE_HTAGS              = NO
+VERBATIM_HEADERS       = YES
+#---------------------------------------------------------------------------
+# Configuration options related to the alphabetical class index
+#---------------------------------------------------------------------------
+ALPHABETICAL_INDEX     = YES
+COLS_IN_ALPHA_INDEX    = 5
+IGNORE_PREFIX          =
+#---------------------------------------------------------------------------
+# Configuration options related to the HTML output
+#---------------------------------------------------------------------------
+GENERATE_HTML          = NO
+HTML_OUTPUT            = html
+HTML_FILE_EXTENSION    = .html
+HTML_HEADER            =
+HTML_FOOTER            =
+HTML_STYLESHEET        =
+HTML_EXTRA_STYLESHEET  =
+HTML_EXTRA_FILES       =
+HTML_COLORSTYLE_HUE    = 220
+HTML_COLORSTYLE_SAT    = 100
+HTML_COLORSTYLE_GAMMA  = 80
+HTML_TIMESTAMP         = NO
+HTML_DYNAMIC_MENUS     = YES
+HTML_DYNAMIC_SECTIONS  = NO
+HTML_INDEX_NUM_ENTRIES = 100
+GENERATE_DOCSET        = NO
+DOCSET_FEEDNAME        = "Doxygen generated docs"
+DOCSET_BUNDLE_ID       = org.doxygen.Project
+DOCSET_PUBLISHER_ID    = org.doxygen.Publisher
+DOCSET_PUBLISHER_NAME  = Publisher
+GENERATE_HTMLHELP      = NO
+CHM_FILE               =
+HHC_LOCATION           =
+GENERATE_CHI           = NO
+CHM_INDEX_ENCODING     =
+BINARY_TOC             = NO
+TOC_EXPAND             = NO
+GENERATE_QHP           = NO
+QCH_FILE               =
+QHP_NAMESPACE          = org.doxygen.Project
+QHP_VIRTUAL_FOLDER     = doc
+QHP_CUST_FILTER_NAME   =
+QHP_CUST_FILTER_ATTRS  =
+QHP_SECT_FILTER_ATTRS  =
+QHG_LOCATION           =
+GENERATE_ECLIPSEHELP   = NO
+ECLIPSE_DOC_ID         = org.doxygen.Project
+DISABLE_INDEX          = NO
+GENERATE_TREEVIEW      = NO
+ENUM_VALUES_PER_LINE   = 4
+TREEVIEW_WIDTH         = 250
+EXT_LINKS_IN_WINDOW    = NO
+FORMULA_FONTSIZE       = 10
+FORMULA_TRANSPARENT    = YES
+USE_MATHJAX            = NO
+MATHJAX_FORMAT         = HTML-CSS
+MATHJAX_RELPATH        = https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/
+MATHJAX_EXTENSIONS     =
+MATHJAX_CODEFILE       =
+SEARCHENGINE           = YES
+SERVER_BASED_SEARCH    = NO
+EXTERNAL_SEARCH        = NO
+SEARCHENGINE_URL       =
+SEARCHDATA_FILE        = searchdata.xml
+EXTERNAL_SEARCH_ID     =
+EXTRA_SEARCH_MAPPINGS  =
+#---------------------------------------------------------------------------
+# Configuration options related to the LaTeX output
+#---------------------------------------------------------------------------
+GENERATE_LATEX         = NO
+LATEX_OUTPUT           = latex
+LATEX_CMD_NAME         =
+MAKEINDEX_CMD_NAME     = makeindex
+LATEX_MAKEINDEX_CMD    = makeindex
+COMPACT_LATEX          = NO
+PAPER_TYPE             = a4
+EXTRA_PACKAGES         =
+LATEX_HEADER           =
+LATEX_FOOTER           =
+LATEX_EXTRA_STYLESHEET =
+LATEX_EXTRA_FILES      =
+PDF_HYPERLINKS         = YES
+USE_PDFLATEX           = YES
+LATEX_BATCHMODE        = NO
+LATEX_HIDE_INDICES     = NO
+LATEX_SOURCE_CODE      = NO
+LATEX_BIB_STYLE        = plain
+LATEX_TIMESTAMP        = NO
+LATEX_EMOJI_DIRECTORY  =
+#---------------------------------------------------------------------------
+# Configuration options related to the RTF output
+#---------------------------------------------------------------------------
+GENERATE_RTF           = NO
+RTF_OUTPUT             = rtf
+COMPACT_RTF            = NO
+RTF_HYPERLINKS         = NO
+RTF_STYLESHEET_FILE    =
+RTF_EXTENSIONS_FILE    =
+RTF_SOURCE_CODE        = NO
+#---------------------------------------------------------------------------
+# Configuration options related to the man page output
+#---------------------------------------------------------------------------
+GENERATE_MAN           = YES
+MAN_OUTPUT             = man
+MAN_EXTENSION          = .3
+MAN_SUBDIR             =
+MAN_LINKS              = NO
+#---------------------------------------------------------------------------
+# Configuration options related to the XML output
+#---------------------------------------------------------------------------
+GENERATE_XML           = NO
+XML_OUTPUT             = xml
+XML_PROGRAMLISTING     = YES
+XML_NS_MEMB_FILE_SCOPE = NO
+#---------------------------------------------------------------------------
+# Configuration options related to the DOCBOOK output
+#---------------------------------------------------------------------------
+GENERATE_DOCBOOK       = NO
+DOCBOOK_OUTPUT         = docbook
+DOCBOOK_PROGRAMLISTING = NO
+#---------------------------------------------------------------------------
+# Configuration options for the AutoGen Definitions output
+#---------------------------------------------------------------------------
+GENERATE_AUTOGEN_DEF   = NO
+#---------------------------------------------------------------------------
+# Configuration options related to the Perl module output
+#---------------------------------------------------------------------------
+GENERATE_PERLMOD       = NO
+PERLMOD_LATEX          = NO
+PERLMOD_PRETTY         = YES
+PERLMOD_MAKEVAR_PREFIX =
+#---------------------------------------------------------------------------
+# Configuration options related to the preprocessor
+#---------------------------------------------------------------------------
+ENABLE_PREPROCESSING   = YES
+MACRO_EXPANSION        = NO
+EXPAND_ONLY_PREDEF     = NO
+SEARCH_INCLUDES        = YES
+INCLUDE_PATH           =
+INCLUDE_FILE_PATTERNS  =
+PREDEFINED             =
+EXPAND_AS_DEFINED      =
+SKIP_FUNCTION_MACROS   = YES
+#---------------------------------------------------------------------------
+# Configuration options related to external references
+#---------------------------------------------------------------------------
+TAGFILES               =
+GENERATE_TAGFILE       =
+ALLEXTERNALS           = NO
+EXTERNAL_GROUPS        = YES
+EXTERNAL_PAGES         = YES
+#---------------------------------------------------------------------------
+# Configuration options related to the dot tool
+#---------------------------------------------------------------------------
+CLASS_DIAGRAMS         = NO
+DIA_PATH               =
+HIDE_UNDOC_RELATIONS   = YES
+HAVE_DOT               = NO
+DOT_NUM_THREADS        = 0
+DOT_FONTNAME           = Helvetica
+DOT_FONTSIZE           = 10
+DOT_FONTPATH           =
+CLASS_GRAPH            = YES
+COLLABORATION_GRAPH    = YES
+GROUP_GRAPHS           = YES
+UML_LOOK               = NO
+UML_LIMIT_NUM_FIELDS   = 10
+TEMPLATE_RELATIONS     = NO
+INCLUDE_GRAPH          = YES
+INCLUDED_BY_GRAPH      = YES
+CALL_GRAPH             = NO
+CALLER_GRAPH           = NO
+GRAPHICAL_HIERARCHY    = YES
+DIRECTORY_GRAPH        = YES
+DOT_IMAGE_FORMAT       = png
+INTERACTIVE_SVG        = NO
+DOT_PATH               =
+DOTFILE_DIRS           =
+MSCFILE_DIRS           =
+DIAFILE_DIRS           =
+PLANTUML_JAR_PATH      =
+PLANTUML_CFG_FILE      =
+PLANTUML_INCLUDE_PATH  =
+DOT_GRAPH_MAX_NODES    = 50
+MAX_DOT_GRAPH_DEPTH    = 0
+DOT_TRANSPARENT        = NO
+DOT_MULTI_TARGETS      = NO
+GENERATE_LEGEND        = YES
+DOT_CLEANUP            = YES
\ No newline at end of file
diff --git a/spm.c b/spm.c
index 152f3f1..478dbb5 100644
--- a/spm.c
+++ b/spm.c
@@ -5,26 +5,18 @@
 
 #include <ctype.h>
 #include <errno.h>
+#include <glob.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <limits.h>
 #include <stdarg.h>
 #include <string.h>
 #include <unistd.h>
-#include <glob.h>
+#include <time.h>
+#include "config.h"
+#include "spm.h"
 
-#define SYSERROR stderr, "%s:%s:%d: %s\n", __FILE__, __FUNCTION__, __LINE__, strerror(errno)
-#define DIRSEP_WIN32 '\\'
-#define DIRSEP_UNIX '/'
-#if defined(_WIN32)
-#define DIRSEP  DIRSEP_WIN32
-#define NOT_DIRSEP DIRSEP_UNIX
-#else
-#define DIRSEP DIRSEP_UNIX
-#define NOT_DIRSEP DIRSEP_WIN32
-#endif
 
-#define PKG_DIR "../pkgs"
 
 /**
  * A wrapper for `popen()` that executes non-interactive programs and reports their exit value.
@@ -33,33 +25,41 @@
  * ~~~{.c}
  * int fd = 1;  // stdout
  * const char *log_file = "log.txt";
- * char *buf;
+ * Process *proc_info;
  * int status;
  *
  * // Send stderr to stdout
- * status = shell(buf, "foo 2>&1");
+ * shell(&proc_info, SHELL_OUTPUT, "foo 2>&1");
  * // Send stdout and stderr to /dev/null
- * status = shell(buf, "bar &>/dev/null");
+ * shell(&proc_info, SHELL_OUTPUT,"bar &>/dev/null");
  * // Send stdout from baz to log.txt
- * status = shell(buf, "baz %d>%s", fd, log_file);
+ * shell(&proc_info, SHELL_OUTPUT, "baz %d>%s", fd, log_file);
  * // Do not record or redirect output from any streams
- * status = shell(NULL, "biff");
+ * shell(&proc_info, SHELL_DEFAULT, "biff");
  * ~~~
  *
- * @param buf buffer to hold program output (to ignore output, set to NULL)
+ * @param Process uninitialized `Process` struct will be populated with process data
  * @param options change behavior of the function
  * @param fmt shell command to execute (accepts `printf` style formatters)
  * @param ... variadic arguments (used by `fmt`)
- * @return shell exit code
  */
-#define SHELL_DEFAULT 1 << 0
-#define SHELL_OUTPUT 1 << 1
-int shell(char **buf, u_int8_t option, const char *fmt, ...) {
+void shell(Process **proc_info, u_int64_t option, const char *fmt, ...) {
     va_list args;
     va_start(args, fmt);
 
-    FILE *proc;
-    int status = -1;
+    size_t bytes_read = 0;
+    size_t i = 0;
+    size_t new_buf_size = 0;
+    clockid_t clkid = CLOCK_REALTIME;
+    FILE *proc = NULL;
+
+    (*proc_info) = (Process *)calloc(1, sizeof(Process));
+    if (!(*proc_info)) {
+        fprintf(SYSERROR);
+        exit(errno);
+    }
+    (*proc_info)->returncode = -1;
+
     char *outbuf = (char *)calloc(1, sizeof(char));
     if (!outbuf) {
         fprintf(SYSERROR);
@@ -73,57 +73,86 @@ int shell(char **buf, u_int8_t option, const char *fmt, ...) {
 
     vsnprintf(cmd, PATH_MAX, fmt, args);
 
+    if (option & SHELL_BENCHMARK) {
+        if (clock_gettime(clkid, &(*proc_info)->start_time) == -1) {
+            perror("clock_gettime");
+            exit(errno);
+        }
+    }
+
     proc = popen(cmd, "r");
     if (!proc) {
-        return status;
+        return;
+    }
+
+    if (option & SHELL_BENCHMARK) {
+        if (clock_gettime(clkid, &(*proc_info)->stop_time) == -1) {
+            perror("clock_gettime");
+            exit(errno);
+        }
+        (*proc_info)->time_elapsed = ((*proc_info)->stop_time.tv_sec - (*proc_info)->start_time.tv_sec)
+                                   + ((*proc_info)->stop_time.tv_nsec - (*proc_info)->start_time.tv_nsec) / 1E9;
     }
 
-    size_t bytes_read = 0;
-    size_t i = 0;
-    size_t new_buf_size = 0;
     if (option & SHELL_OUTPUT) {
-        *buf = (char *)calloc(BUFSIZ, sizeof(char));
+        (*proc_info)->output = (char *)calloc(BUFSIZ, sizeof(char));
 
-        while (!feof(proc)) {
-            *outbuf = fgetc(proc);
+        while ((*outbuf = fgetc(proc)) != EOF) {
 
             if (i >= BUFSIZ) {
                 new_buf_size = BUFSIZ + (i + bytes_read);
-                (*buf) = (char *)realloc((*buf), new_buf_size);
+                (*proc_info)->output = (char *)realloc((*proc_info)->output, new_buf_size);
                 i = 0;
             }
-            if (isascii(*outbuf)) {
-                (*buf)[bytes_read] = *outbuf;
+            if (*outbuf) {
+                (*proc_info)->output[bytes_read] = *outbuf;
             }
             bytes_read++;
             i++;
         }
     }
-    status = pclose(proc);
+    (*proc_info)->returncode = pclose(proc);
     va_end(args);
     free(outbuf);
     free(cmd);
-    return status;
-};
+}
 
-/*
+/**
+ * Free process resources allocated by `shell()`
+ * @param proc_info `Process` struct
+ */
+void shell_free(Process *proc_info) {
+    free(proc_info->output);
+    free(proc_info);
+}
+
+/**
+ * Extract a single file from a tar archive into a directory
+ *
+ * @param archive path to tar archive
+ * @param filename known path inside the archive to extract
+ * @param destination where to extract file to (must exist)
+ * @return
+ */
 int tar_extract_file(const char *archive, const char* filename, const char *destination) {
+    Process *proc = NULL;
     int status = -1;
     char cmd[PATH_MAX];
     char output[3];
+
     sprintf(cmd, "tar xf %s %s -C %s 2>&1", archive, filename, destination);
-    FILE *proc = popen(cmd, "r");
+
+    shell(&proc, SHELL_OUTPUT, cmd);
     if (!proc) {
-        return status;
-    }
-    while (!feof(proc)) {
-        fgets(output, 2, proc);
-        printf("%s", output);
+        printf("%s\n", proc->output);
+        fprintf(SYSERROR);
+        return -1;
     }
-    putchar('\n');
-    return pclose(proc);
+    status = proc->returncode;
+    shell_free(proc);
+
+    return status;
 };
- */
 
 /**
  * glob callback function
@@ -160,7 +189,7 @@ int num_chars(const char *sptr, int ch) {
  * @return 0 = success, -1 = failure
  */
 int startswith(const char *sptr, const char *pattern) {
-    for (int i = 0; i < strlen(pattern); i++) {
+    for (size_t i = 0; i < strlen(pattern); i++) {
         if (sptr[i] != pattern[i]) {
             return -1;
         }
@@ -212,13 +241,40 @@ char *normpath(const char *path) {
 }
 
 /**
+ * Deletes any characters matching `chars` from `sptr` string
+ *
+ * @param sptr string to be modified in-place
+ * @param chars a string containing characters (e.g. " \n" would delete whitespace and line feeds)
+ */
+void strchrdel(char *sptr, const char *chars) {
+    while (*sptr != '\0') {
+        for (int i = 0; chars[i] != '\0'; i++) {
+            if (*sptr == chars[i]) {
+                memmove(sptr, sptr + 1, strlen(sptr));
+            }
+        }
+        sptr++;
+    }
+}
+
+int64_t strchroff(char *sptr, int ch) {
+    char *tmp = sptr;
+    while (*tmp != '\0') {
+        if (*tmp == ch) {
+            return tmp - sptr;
+        }
+        tmp++;
+    }
+    return -1;
+}
+/**
  * This function scans `sptr` from right to left removing any matches to `suffix`
  * from the string.
  *
  * @param sptr string to be modified
  * @param suffix string to be removed from `sptr`
  */
-void strip(char *sptr, const char *suffix) {
+void substrdel(char *sptr, const char *suffix) {
     if (!sptr || !suffix) {
         return;
     }
@@ -237,24 +293,7 @@ void strip(char *sptr, const char *suffix) {
         // Purge the suffix
         memset(target, '\0', suffix_len);
         // Recursive call continues removing suffix until it is gone
-        strip(sptr, suffix);
-    }
-}
-
-/**
- * Deletes any characters matching `chars` from `sptr` string
- *
- * @param sptr string to be modified in-place
- * @param chars a string containing characters (e.g. " \n" would delete whitespace and line feeds)
- */
-void strchrdel(char *sptr, const char *chars) {
-    while (*sptr != '\0') {
-        for (int i = 0; chars[i] != '\0'; i++) {
-           if (*sptr == chars[i]) {
-               memmove(sptr, sptr + 1, strlen(sptr));
-           }
-        }
-        sptr++;
+        strip(sptr);
     }
 }
 
@@ -320,33 +359,179 @@ char *find_package(const char *filename) {
     return find_file(PKG_DIR, filename);
 }
 
-int main() {
+char** split(char *sptr, const char* delim)
+{
+    int split_alloc = 0;
+    for (int i = 0; i < strlen(delim); i++) {
+        split_alloc += num_chars(sptr, delim[i]);
+    }
+    char **result = (char **)calloc(split_alloc + 2, sizeof(char *));
+
+    int i = 0;
+    //char *token = strsep(&sptr, delim);
+    char *token = NULL;
+    while((token = strsep(&sptr, delim)) != NULL) {
+        result[i] = (char *)calloc(1, sizeof(char) * strlen(token) + 1);
+        strcpy(result[i], token);
+        i++;
+    }
+    return result;
+}
+
+void split_free(char **ptr) {
+    for (int i = 0; ptr[i] != NULL; i++) {
+        free(ptr[i]);
+    }
+    free(ptr);
+}
+
+char *substring_between(char *sptr, const char *delims) {
+    int delim_count = strlen(delims);
+    if (delim_count != 2) {
+        return NULL;
+    }
+
+    char *start = strpbrk(sptr, &delims[0]);
+    char *end = strpbrk(sptr, &delims[1]);
+    if (!start || !end) {
+        return NULL;
+    }
+    start++;    // ignore leading delimiter
+
+    long int length = end - start;
+
+    char *result = (char *)calloc(1, sizeof(char) * length);
+    if (!result) {
+        return NULL;
+    }
+
+    char *tmp = result;
+    while (start != end) {
+        *tmp = *start;
+        tmp++;
+        start++;
+    }
+
+    return result;
+}
+
+/**
+ * Uses `readelf` to determine whether a RPATH or RUNPATH is present
+ *
+ * TODO: Replace with OS-native solution(s)
+ *
+ * @param filename path to executable or library
+ * @return -1=OS error, 0=has rpath, 1=not found
+ */
+int has_rpath(const char *filename) {
+    int result = 1;
+    Process *proc_info = NULL;
+    char *path = strdup(filename);
+    const char *preamble = "readelf -d";
+
+    // sanitize input path
+    strchrdel(path, "&;|");
+
+    char sh_cmd[strlen(preamble) + 1 + strlen(path) + 1];
+    memset(sh_cmd, '\0', sizeof(sh_cmd));
+
+    sprintf(sh_cmd, "%s %s", preamble, path);
+    free(path);
+
+    shell(&proc_info, SHELL_OUTPUT, sh_cmd);
+    if (!proc_info) {
+        fprintf(SYSERROR);
+        return -1;
+    }
+
+   strip(proc_info->output);
+   char **lines = split(proc_info->output, "\n");
+   for (int i = 0; lines[i] != NULL; i++) {
+       if (strstr(lines[i], "RPATH") || strstr(lines[i], "RUNPATH")) {
+           result = 0;
+       }
+   }
+    shell_free(proc_info);
+   split_free(lines);
+   return result;
+}
+
+/**
+ * Parses `readelf` output and returns an RPATH or RUNPATH if one is defined
+ *
+ * TODO: Replace with OS-native solution(s)
+ *
+ * @param filename path to executable or library
+ * @return RPATH string, NULL=error (caller is responsible for freeing memory)
+ */
+char *get_rpath(const char *filename) {
+    if ((has_rpath(filename)) != 0) {
+        return NULL;
+    }
+
+    Process *proc_info = NULL;
+    char *path = strdup(filename);
+    const char *preamble = "readelf -d";
+    char *rpath = NULL;
+
+    // sanitize input path
+    strchrdel(path, "&;|");
+
+    char sh_cmd[strlen(preamble) + 1 + strlen(path) + 1];
+    memset(sh_cmd, '\0', sizeof(sh_cmd));
+
+    sprintf(sh_cmd, "%s %s", preamble, path);
+    free(path);
+
+    shell(&proc_info, SHELL_OUTPUT, sh_cmd);
+    if (!proc_info) {
+        fprintf(SYSERROR);
+        return NULL;
+    }
+
+    strip(proc_info->output);
+    char **lines = split(proc_info->output, "\n");
+    for (int i = 0; lines[i] != NULL; i++) {
+        if (strstr(lines[i], "RPATH") || strstr(lines[i], "RUNPATH")) {
+            rpath = substring_between(lines[i], "[]");
+            break;
+        }
+    }
+    shell_free(proc_info);
+    split_free(lines);
+    return rpath;
+}
+
+int main(int argc, char *argv[]) {
+    // not much to see here yet
+    // at the moment this will all be random tests, for better or worse
+    // everything here is subject to change without notice
+
     const char *pkg_name = "python";
     char *package = NULL;
     package = find_package(pkg_name);
     if (package != NULL) {
         printf("Package found: %s\n", package);
         free(package);
-    }
-    else {
-        fprintf(stderr,"Package does not exist: %s\n", pkg_name);
+    } else {
+        fprintf(stderr, "Package does not exist: %s\n", pkg_name);
     }
 
     const char *testpath = "x:\\a\\b\\c";
     const char *teststring = "this is test!";
+    const char *testprog = "/tmp/a.out";
     char *normalized = normpath(testpath);
-    char *buf = NULL;
 
     printf("%s becomes %s\n", testpath, normalized);
     printf("%d\n", startswith(testpath, "x:\\"));
     printf("%d\n", endswith(teststring, "test!"));
-    //tar_extract_file("one", "two", testpath);
-
-    int retval = -1;
-    retval = shell(&buf, SHELL_OUTPUT, "env; env; env; env; env; env; env; env");
-    strip(buf, "\n");
-    printf("%s\n", buf);
-
     free(normalized);
+
+    if ((has_rpath(testprog)) == 0) {
+        printf("RPATH found\n");
+        char *rpath = get_rpath(testprog);
+        printf("RPATH is: %s\n", rpath);
+        free(rpath);
+    }
     return 0;
 }
\ No newline at end of file
diff --git a/spm.h b/spm.h
new file mode 100644
index 0000000..381ddb7
--- /dev/null
+++ b/spm.h
@@ -0,0 +1,68 @@
+#ifndef SPM_SPM_H
+#define SPM_SPM_H
+
+// spm.c
+#define SYSERROR stderr, "%s:%s:%d: %s\n", __FILE__, __FUNCTION__, __LINE__, strerror(errno)
+#define DIRSEP_WIN32 '\\'
+#define DIRSEP_UNIX '/'
+#if defined(_WIN32)
+#define DIRSEP  DIRSEP_WIN32
+#define NOT_DIRSEP DIRSEP_UNIX
+#else
+#define DIRSEP DIRSEP_UNIX
+#define NOT_DIRSEP DIRSEP_WIN32
+#endif
+
+#define PKG_DIR "../pkgs"
+
+#define SHELL_DEFAULT 1L << 0L
+#define SHELL_OUTPUT 1L << 1L
+#define SHELL_BENCHMARK 1L << 2L
+typedef struct {
+    struct timespec start_time, stop_time;
+    double time_elapsed;
+    int returncode;
+    char *output;
+} Process;
+
+void shell(Process **proc_info, u_int64_t option, const char *fmt, ...);
+void shell_free(Process *proc_info);
+int tar_extract_file(const char *archive, const char* filename, const char *destination);
+int errglob(const char *epath, int eerrno);
+int num_chars(const char *sptr, int ch);
+int startswith(const char *sptr, const char *pattern);
+int endswith(const char *sptr, const char *pattern);
+char *normpath(const char *path);
+void strchrdel(char *sptr, const char *chars);
+int64_t strchroff(char *sptr, int ch);
+void substrdel(char *sptr, const char *suffix);
+char *find_file(const char *root, const char *filename);
+char *find_package(const char *filename);
+char** split(char *sptr, const char* delim);
+void split_free(char **ptr);
+char *substring_between(char *sptr, const char *delims);
+int has_rpath(const char *filename);
+char *get_rpath(const char *filename);
+
+
+
+// config.c
+#define CONFIG_BUFFER_SIZE 1024
+
+typedef struct {
+    char *key;
+    char *value;
+} Config;
+
+char *lstrip(char *sptr);
+char *strip(char *sptr);
+int isempty(char *sptr);
+int isquoted(char *sptr);
+Config **config_read(const char *filename);
+void config_free(Config **config);
+void config_test(void);
+
+
+
+
+#endif //SPM_SPM_H