Add EACCESS error and use it

Return this error if using an archive in the wrong access mode,
ie. write to an archive opened for reading, or vice-versa.
Previously EAPI was returned which is probably not as useful.

2 files changed, 11 insertions, 7 deletions

diff --git a/src/microtar.c b/src/microtar.c
index 0653adb..3856437 100644
--- a/src/microtar.c
+++ b/src/microtar.c
@@ -297,6 +297,7 @@ const char* mtar_strerror(int err)
     case MTAR_EAPI:         return "API usage error";
     case MTAR_ENAMETOOLONG: return "name too long";
     case MTAR_ETOOSHORT:    return "file too short";
+    case MTAR_EACCESS:      return "wrong access mode";
     default:                return "unknown error";
     }
 }
@@ -348,7 +349,7 @@ int mtar_rewind(mtar_t* tar)
 int mtar_next(mtar_t* tar)
 {
     if(tar->access != MTAR_READ)
-        return MTAR_EAPI;
+        return MTAR_EACCESS;
 
     if(tar->state & S_HEADER_VALID) {
         tar->state &= ~S_HEADER_VALID;
@@ -365,7 +366,7 @@ int mtar_next(mtar_t* tar)
 int mtar_foreach(mtar_t* tar, mtar_foreach_cb cb, void* arg)
 {
     if(tar->access != MTAR_READ)
-        return MTAR_EAPI;
+        return MTAR_EACCESS;
 
     int err = mtar_rewind(tar);
     if(err)
@@ -402,7 +403,7 @@ int mtar_find(mtar_t* tar, const char* name)
 int mtar_read_data(mtar_t* tar, void* ptr, unsigned size)
 {
     if(tar->access != MTAR_READ)
-        return MTAR_EAPI;
+        return MTAR_EACCESS;
     if(!(tar->state & S_HEADER_VALID))
         return MTAR_EAPI;
 
@@ -422,7 +423,7 @@ int mtar_read_data(mtar_t* tar, void* ptr, unsigned size)
 int mtar_seek_data(mtar_t* tar, int offset, int whence)
 {
     if(tar->access != MTAR_READ)
-        return MTAR_EAPI;
+        return MTAR_EACCESS;
     if(!(tar->state & S_HEADER_VALID))
         return MTAR_EAPI;
 
@@ -474,7 +475,7 @@ int mtar_eof_data(mtar_t* tar)
 int mtar_write_header(mtar_t* tar, const mtar_header_t* h)
 {
     if(tar->access != MTAR_WRITE)
-        return MTAR_EAPI;
+        return MTAR_EACCESS;
     if(((tar->state & S_WROTE_DATA) && !(tar->state & S_WROTE_DATA_EOF)) ||
        (tar->state & S_WROTE_FINALIZE))
         return MTAR_EAPI;
@@ -536,6 +537,8 @@ int mtar_write_dir_header(mtar_t* tar, const char* name)
 
 int mtar_write_data(mtar_t* tar, const void* ptr, unsigned size)
 {
+    if(tar->access != MTAR_WRITE)
+        return MTAR_EACCESS;
     if(!(tar->state & S_WROTE_HEADER) ||
        (tar->state & S_WROTE_DATA_EOF) ||
        (tar->state & S_WROTE_FINALIZE))
@@ -558,7 +561,7 @@ int mtar_write_data(mtar_t* tar, const void* ptr, unsigned size)
 int mtar_end_data(mtar_t* tar)
 {
     if(tar->access != MTAR_WRITE)
-        return MTAR_EAPI;
+        return MTAR_EACCESS;
     if((tar->state & S_WROTE_DATA_EOF) ||
        (tar->state & S_WROTE_FINALIZE))
         return MTAR_EAPI;
@@ -578,7 +581,7 @@ int mtar_end_data(mtar_t* tar)
 int mtar_finalize(mtar_t* tar)
 {
     if(tar->access != MTAR_WRITE)
-        return MTAR_EAPI;
+        return MTAR_EACCESS;
     if(((tar->state & S_WROTE_DATA) && !(tar->state & S_WROTE_DATA_EOF)) ||
        (tar->state & S_WROTE_FINALIZE))
         return MTAR_EAPI;
diff --git a/src/microtar.h b/src/microtar.h
index 6197a3d..12e43e0 100644
--- a/src/microtar.h
+++ b/src/microtar.h
@@ -45,6 +45,7 @@ enum mtar_error {
     MTAR_EAPI         = -12,
     MTAR_ENAMETOOLONG = -13,
     MTAR_ETOOSHORT    = -14,
+    MTAR_EACCESS      = -15,
     MTAR_ELAST        = MTAR_ETOOSHORT,
 };