1 files changed, 154 insertions, 0 deletions
diff --git a/find.c b/find.c
new file mode 100644
index 0000000..84ded16
--- /dev/null
+++ b/find.c
@@ -0,0 +1,154 @@
+#include "spm.h"
+
+/**
+ * glob callback function
+ * @param epath path to file that generated the error condition
+ * @param eerrno the error condition
+ * @return the error condition
+ */
+int errglob(const char *epath, int eerrno) {
+    fprintf(stderr, "glob matching error: %s (%d)", epath, eerrno);
+    return eerrno;
+}
+
+/**
+ * Scan a directory for a file by name, or by wildcard
+ *
+ * @param root directory path to scan
+ * @param filename file to find (wildcards accepted)
+ * @return success=path to file, failure=NULL
+ */
+char *find_file(const char *root, const char *filename) {
+    glob_t results;
+    int glob_flags = 0;
+    int match = 0;
+    char *rootpath = NULL;
+    char *path = NULL;
+
+    // GUARD
+    if (!root || !filename || strstr(filename, "..") || strstr(filename, "./")) {
+        return NULL;
+    }
+
+    if (!(path = (char *)calloc(PATH_MAX + 1, sizeof(char)))) {
+        fprintf(SYSERROR);
+        exit(errno);
+    }
+
+    if (!(rootpath = realpath(root, NULL))) {
+        return NULL;
+    }
+
+    strcat(path, rootpath);
+    strcat(path, "/");
+    strcat(path, filename);
+
+    // Save a little time if the file exists
+    if (access(path, F_OK) != -1) {
+        return path;
+    }
+
+    // Inject wildcard
+    strcat(path, "*");
+    // Search for the file
+    match = glob(path, glob_flags, errglob, &results);
+
+    if (match != 0) {
+        // report critical errors except GLOB_NOMATCH
+        if (match == GLOB_NOSPACE || match == GLOB_ABORTED) {
+            fprintf(SYSERROR);
+        }
+        return NULL;
+    }
+
+    // Resize path to the length of the first match
+    char *want = results.gl_pathv[0];
+    if (!(path = (char *)realloc(path, sizeof(char) * (strlen(want) + 1)))) {
+        fprintf(SYSERROR);
+        exit(errno);
+    }
+
+    // Replace path string with wanted path string
+    strncpy(path, want, strlen(want));
+
+    free(rootpath);
+    globfree(&results);
+    return path;
+}
+
+/**
+ * Scan the package directory for a package by name
+ * @param filename file to find
+ * @return success=path to file, failure=NULL
+ */
+char *find_package(const char *filename) {
+    return find_file(PKG_DIR, filename);
+}
+
+/**
+ * Determine whether `pattern` is present within a file
+ * @param filename
+ * @param pattern
+ * @return 0=found, 1=not found, -1=OS error
+ */
+int find_in_file(const char *filename, const char *pattern) {
+    int result = 1;  // default "not found"
+
+    FILE *fp = fopen(filename, "rb");
+    if (!fp) {
+        return -1;
+    }
+
+    long int file_len = get_file_size(filename);
+    if (file_len < 0) {
+        return -1;
+    }
+    char *buffer = (char *)calloc((size_t) file_len, sizeof(char));
+    if (!buffer) {
+        return -1;
+    }
+    size_t pattern_len = strlen(pattern);
+
+    fread(buffer, (size_t) file_len, sizeof(char), fp);
+    fclose(fp);
+
+    for (size_t i = 0; i < file_len; i++) {
+        if (!memcmp(&buffer[i], pattern, pattern_len)) {
+            result = 0;  // found
+            break;
+        }
+    }
+    free(buffer);
+    return result;
+}
+
+/**
+ * Get the full path of a shell command
+ * @param program
+ * @return success=absolute path to program, failure=NULL
+ */
+char *find_executable(const char *program) {
+    int found = 0;
+    char *result = NULL;
+    char *env_path = NULL;
+    env_path = getenv("PATH");
+    if (!env_path) {
+        return NULL;
+    }
+    char **search_paths = split(env_path, ":");
+
+    char buf[PATH_MAX];
+    for (int i = 0; search_paths[i] != NULL; i++) {
+        sprintf(buf, "%s%c%s", search_paths[i], DIRSEP, program);
+        if (access(buf, F_OK | X_OK) == 0) {
+            found = 1;
+            break;
+        }
+        memset(buf, '\0', sizeof(buf));
+    }
+    if (found) {
+        result = strdup(buf);
+    }
+    split_free(search_paths);
+    return result;
+}