Initial release

1 files changed, 173 insertions, 0 deletions

diff --git a/sysinfo.c b/sysinfo.c
new file mode 100644
index 0000000..3805dcc
--- /dev/null
+++ b/sysinfo.c
@@ -0,0 +1,173 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <strings.h>
+#include <errno.h>
+
+#define MEMINFO_FILE "/proc/meminfo"
+#define MTAB_FILE "/etc/mtab"
+
+#define BAD_OPEN_MESSAGE					\
+"Error: /proc must be mounted\n"				\
+"  To mount /proc at boot you need an /etc/fstab line like:\n"	\
+"      /proc   /proc   proc    defaults\n"			\
+"  In the meantime, run \"mount /proc /proc -t proc\"\n"
+
+/* This macro opens filename only if necessary and seeks to 0 so
+ * that successive calls to the functions are more efficient.
+ * It also reads the current contents of the file into the global buf.
+ */
+#define FILE_TO_BUF(filename) do{				\
+    static int fd, local_n;					\
+    if ((fd = open(filename, O_RDONLY)) == -1) {		\
+	fputs(BAD_OPEN_MESSAGE, stderr);			\
+	fflush(NULL);						\
+	_exit(102);						\
+    }								\
+    lseek(fd, 0L, SEEK_SET);					\
+    if ((local_n = read(fd, buf, sizeof buf - 1)) < 0) {	\
+	perror(filename);					\
+	fflush(NULL);						\
+	_exit(103);						\
+    }								\
+    buf[local_n] = '\0';					\
+    close(fd);							\
+}while(0)
+
+
+typedef struct mem_table_struct {
+  const char *name;     /* memory type name */
+  unsigned long *slot; /* slot in return struct */
+} mem_table_struct;
+
+static int compare_mem_table_structs(const void *a, const void *b){
+  return strcmp(((const mem_table_struct*)a)->name,((const mem_table_struct*)b)->name);
+}
+
+size_t get_free_memory(void){
+  char buf[4096];
+  unsigned long kb_main_buffers, kb_main_cached, kb_main_free;
+  char namebuf[16]; /* big enough to hold any row name */
+  mem_table_struct findme = { namebuf, NULL};
+  mem_table_struct *found;
+  char *head;
+  char *tail;
+
+  const mem_table_struct mem_table[] = {
+    {"Buffers",      &kb_main_buffers}, // important
+    {"Cached",       &kb_main_cached},  // important
+    {"MemFree",      &kb_main_free},    // important
+  };
+  const int mem_table_count = sizeof(mem_table)/sizeof(mem_table_struct);
+
+  FILE_TO_BUF(MEMINFO_FILE);
+
+  head = buf;
+  for(;;){
+    tail = strchr(head, ':');
+    if(!tail) break;
+    *tail = '\0';
+    if(strlen(head) >= sizeof(namebuf)){
+      head = tail+1;
+      goto nextline;
+    }
+    strcpy(namebuf,head);
+    found = bsearch(&findme, mem_table, mem_table_count,
+        sizeof(mem_table_struct), compare_mem_table_structs
+    );
+    head = tail+1;
+    if(!found) goto nextline;
+    *(found->slot) = strtoul(head,&tail,10);
+nextline:
+    tail = strchr(head, '\n');
+    if(!tail) break;
+    head = tail+1;
+  }
+  
+  return (kb_main_buffers + kb_main_cached + kb_main_free) * 1024;
+}
+
+
+int get_file_fs(const char *fname, size_t size, char *fs) {
+  int err = 0;
+  char buf[4096];
+  char *fn;
+
+  char *head;
+  char *tail;
+
+  size_t len, max = 0;
+  struct stat st;
+  
+  if ((!fname)||(!fs)||(size < 3)) return EINVAL;
+  
+  if (*fname == '/') {
+    fn = (char*)fname;
+  } else {
+    if (!getcwd(buf, 4095)) return errno;
+    fn = malloc(strlen(fname) + strlen(buf) + 2);
+    if (!fn) return ENOMEM;
+    sprintf(fn, "%s/%s", buf, fname);
+  }
+  
+  if (!stat(fn, &st)) {
+    if (S_ISBLK(st.st_mode)) {
+	strcpy(fs, "raw");
+	goto clean;
+    }
+  }
+  
+  FILE_TO_BUF(MTAB_FILE);
+
+  head = buf;
+  for(;;){
+    head = strchr(head, ' ');
+    if(!head) break;
+
+    head += 1;
+    tail = strchr(head, ' ');
+    if(!tail) break;
+    
+    *tail = '\0';
+
+    len = strlen(head);
+    if((len <= max)||(strncmp(head, fn, len))) {
+      head = tail+1;
+      goto nextline;
+    }
+    
+    head = tail + 1;
+    tail = strchr(head, ' ');
+    if(!tail) break;
+
+    *tail = '\0';
+
+    if (!strncasecmp(head,"root",4)) {
+	head = tail+1;
+	goto nextline;
+    }
+    
+    max = len;
+
+    if (strlen(head) >= size) err = EFAULT;
+    else {
+	err = 0;
+	strcpy(fs, head);
+    }
+    
+    head = tail+1;
+nextline:
+    tail = strchr(head, '\n');
+    if(!tail) break;
+    head = tail+1;
+  }
+
+clean:  
+  if (fn != fname) free(fn);
+
+  return err;
+}