Refactor project structure

1 files changed, 237 insertions, 0 deletions

diff --git a/src/relocation.c b/src/relocation.c
new file mode 100644
index 0000000..13ae799
--- /dev/null
+++ b/src/relocation.c
@@ -0,0 +1,237 @@
+#include "spm.h"
+
+int replace_text(char *data, const char *spattern, const char *sreplacement) {
+    char *tmp = data;
+    size_t data_len = strlen(data);
+    size_t spattern_len = strlen(spattern);
+    size_t sreplacement_len = strlen(sreplacement);
+
+    if (sreplacement_len > spattern_len) {
+        fprintf(stderr, "replacement string too long\n");
+        return -1;
+    }
+
+    while (*tmp != '\0') {
+        if (strncmp(tmp, spattern, spattern_len) == 0) {
+            memmove(tmp, sreplacement, sreplacement_len);
+            memmove(tmp + sreplacement_len, tmp + spattern_len, data_len - spattern_len);
+        }
+        tmp++;
+    }
+    return 0;
+}
+
+/**
+ * Replace all occurrences of `oldstr` in file `path` with `newstr`
+ * @param filename
+ * @param oldstr
+ * @param newstr
+ * @return success=0, failure=-1, or value of `ferror()`
+ */
+int file_replace_text(char *filename, const char *spattern, const char *sreplacement) {
+    char data[BUFSIZ];
+    char tempfile[PATH_MAX];
+    FILE *fp = NULL;
+    if ((fp = fopen(filename, "r")) == NULL) {
+        perror(filename);
+        return -1;
+    }
+
+    sprintf(tempfile, "%s.spmfrt", filename);
+    FILE *tfp = NULL;
+    if ((tfp = fopen(tempfile, "w+")) == NULL) {
+        perror(tempfile);
+        return -1;
+    }
+
+    // Zero the data buffer
+    memset(data, '\0', BUFSIZ);
+    while(fgets(data, BUFSIZ, fp) != NULL) {
+        replace_text(data, spattern, sreplacement);
+        fprintf(tfp, "%s", data);
+    }
+    fclose(fp);
+    rewind(tfp);
+
+    // Truncate the original file
+    if ((fp = fopen(filename, "w+")) == NULL) {
+        perror(filename);
+        return -1;
+    }
+    // Zero the data buffer once more
+    memset(data, '\0', BUFSIZ);
+    // Dump the contents of the temporary file into the original file
+    while(fgets(data, BUFSIZ, tfp) != NULL) {
+        fprintf(fp, "%s", data);
+    }
+    fclose(fp);
+    fclose(tfp);
+
+    // Remove temporary file
+    unlink(tempfile);
+    return 0;
+}
+
+/**
+ * Free memory allocated by `prefixes_read` function
+ * @param entry array of RelocationEntry
+ */
+void prefixes_free(RelocationEntry **entry) {
+    if (!entry) {
+        return;
+    }
+    for (int i = 0; entry[i] != NULL; i++) {
+        if (entry[i]->prefix) free(entry[i]->prefix);
+        if (entry[i]->path) free(entry[i]->path);
+        if (entry[i]) free(entry[i]);
+    }
+    free(entry);
+}
+
+/**
+ * Parse a prefix file
+ *
+ * The file format is as follows:
+ *
+ * ~~~
+ * #prefix
+ * path
+ * #prefix
+ * path
+ * #...N
+ * ...N
+ * ~~~
+ * @param filename
+ * @return success=array of RelocationEntry, failure=NULL
+ */
+RelocationEntry **prefixes_read(const char *filename) {
+    size_t i = 0;
+    int record_count = 0;
+    int parity = 0;
+    FILE *fp = fopen(filename, "r");
+    if (!fp) {
+        fprintf(SYSERROR);
+        return NULL;
+    }
+    RelocationEntry **entry = NULL;
+    char line[BUFSIZ];
+    memset(line, '\0', BUFSIZ);
+
+    while (fgets(line, BUFSIZ, fp) != NULL) {
+        if (isempty(line)) {
+            continue;
+        }
+        record_count++;
+    }
+    rewind(fp);
+
+    // Initialize the relocation entry array
+    if (record_count == 0) {
+        return NULL;
+    }
+
+    parity = record_count % 2;
+    if (parity != 0) {
+        fprintf(stderr, "%s: records are not divisible by 2 (got: %d %% 2 = %d)\n", filename, record_count, parity);
+        return NULL;
+    }
+    record_count /= 2;
+
+    entry = (RelocationEntry **)calloc(record_count + 1, sizeof(RelocationEntry *));
+    if (!entry) {
+        return NULL;
+    }
+    for (int i = 0; i < record_count; i++) {
+        entry[i] = (RelocationEntry *) calloc(1, sizeof(RelocationEntry));
+        if (!entry[i]) {
+            return NULL;
+        }
+    }
+
+    int do_prefix = 0;
+    int do_path = 0;
+    while (fgets(line, BUFSIZ, fp) != NULL) {
+        char *wtf = line;
+        if (isempty(line)) {
+            continue;
+        }
+        if (startswith(line, "#") == 0) {
+            do_prefix = 1;
+        }
+        else {
+            do_path = 1;
+        }
+
+        // Allocate a relocation record
+        if (!entry[i]) {
+            fclose(fp);
+            return NULL;
+        }
+
+
+        if (do_prefix) {
+            // Populate prefix data (a prefix starts with a #)
+            entry[i]->prefix = (char *) calloc(strlen(line) + 1, sizeof(char));
+            if (!entry[i]->prefix) {
+                fclose(fp);
+                return NULL;
+            }
+            strncpy(entry[i]->prefix, line, strlen(line));
+            // Remove prefix delimiter and whitespace
+            strchrdel(entry[i]->prefix, "#");
+            entry[i]->prefix = strip(entry[i]->prefix);
+            do_prefix = 0;
+            continue;
+        }
+
+        else if (do_path) {
+            // Populate path data
+            entry[i]->path = (char *) calloc(strlen(line) + 1, sizeof(char));
+            if (!entry[i]->path) {
+                fclose(fp);
+                return NULL;
+            }
+            strncpy(entry[i]->path, line, strlen(line));
+            entry[i]->path = strip(entry[i]->path);
+            do_path = 0;
+        }
+        i++;
+    }
+    fclose(fp);
+    return entry;
+}
+
+int relocate(const char *_filename, const char *_oldstr, const char *_newstr) {
+    int returncode;
+    Process *proc = NULL;
+    char *oldstr = strdup(_oldstr);
+    char *newstr = strdup(_newstr);
+    char *filename = strdup(_filename);
+    char cmd[PATH_MAX];
+
+    memset(cmd, '\0', sizeof(cmd));
+    sprintf(cmd, "reloc \"%s\" \"%s\" \"%s\" \"%s\"", oldstr, newstr, filename, filename);
+
+    // sanitize command
+    strchrdel(cmd, "&;|");
+
+    shell(&proc, SHELL_OUTPUT, cmd);
+    if (!proc) {
+        free(oldstr);
+        free(newstr);
+        free(filename);
+        return -1;
+    }
+
+    returncode = proc->returncode;
+    if (returncode != 0 && proc->output) {
+        fprintf(stderr, proc->output);
+    }
+
+    shell_free(proc);
+    free(oldstr);
+    free(newstr);
+    free(filename);
+    return returncode;
+}
+