| -rw-r--r-- | NEWS | 8 | ||||
| -rw-r--r-- | doc/pies.texi | 15 | ||||
| -rw-r--r-- | lib/envop.c | 51 | ||||
| -rw-r--r-- | src/pies.c | 22 |
4 files changed, 77 insertions, 19 deletions
@@ -1,2 +1,2 @@ -GNU Pies NEWS -- history of user-visible changes. 2019-06-06 +GNU Pies NEWS -- history of user-visible changes. 2019-06-07 See the end of file for copying conditions. @@ -57,2 +57,8 @@ to variable expansion. +** eval "VALUE" +Perform variable expansion on VALUE and discard the result (similar +to the shell ":" command). Useful for side effects, e.g.: + + eval ${HOME:=/home/t} + ** unset NAME diff --git a/doc/pies.texi b/doc/pies.texi index 63064e5..4bd2f8f 100644 --- a/doc/pies.texi +++ b/doc/pies.texi @@ -1066,2 +1066,3 @@ env @{ set "@var{name}=@var{value}"; + eval "@var{value}"; unset @var{pattern}; @@ -1125,2 +1126,16 @@ env @{ +@deffn {env} eval "@var{value}" +Perform variable expansion on @var{value} and discard the result. This +is useful for side-effects. For example, to provide default value for +the @env{LD_LIBRARY_PATH} variable, one may write: + +@example +@group +env @{ + eval "$@{LD_LIBRARY_PATH:=/usr/local/lib@}"; +@} +@end group +@end example +@end deffn + @deffn {env} unset @var{pattern} diff --git a/lib/envop.c b/lib/envop.c index ce24b92..93bd425 100644 --- a/lib/envop.c +++ b/lib/envop.c @@ -169,9 +169,11 @@ environ_set (environ_t *env, char const *name, char const *value) - if (!name) + if (!value) { - errno = EINVAL; - return -1; + if (!name) + { + errno = EINVAL; + return -1; + } + return environ_unset (env, name, value); } - if (!value) - return environ_unset (env, name, value); @@ -193,3 +195,14 @@ environ_set (environ_t *env, char const *name, char const *value) - if (strcmp (name, ":") == 0) + if (ws.ws_envbuf) + { + free (env->env_base); + env->env_base = ws.ws_envbuf; + env->env_count = ws.ws_envidx; + env->env_max = ws.ws_envsiz; + ws.ws_envbuf = NULL; + ws.ws_envidx = 0; + ws.ws_envsiz = 0; + } + + if (name == NULL || strcmp (name, ":") == 0) { @@ -336,2 +349,3 @@ envop_entry_add (struct envop_entry **head, size_t s; + char *p; @@ -343,3 +357,3 @@ envop_entry_add (struct envop_entry **head, case envop_set: - if (!name || !(*name == ':' || valid_envar_name (name))) + if (name && !(*name == ':' || valid_envar_name (name))) { @@ -361,7 +375,5 @@ envop_entry_add (struct envop_entry **head, if (name) - { - s += strlen (name) + 1; - if (value) - s += strlen (value) + 1; - } + s += strlen (name) + 1; + if (value) + s += strlen (value) + 1; op = malloc (s); @@ -373,11 +385,14 @@ envop_entry_add (struct envop_entry **head, op->value = NULL; + + p = (char*)(op + 1); if (name) { - op->name = (char*)(op + 1); + op->name = p; strcpy (op->name, name); - if (value) - { - op->value = op->name + strlen (name) + 1; - strcpy (op->value, value); - } + p += strlen (name) + 1; + } + if (value) + { + op->value = p; + strcpy (op->value, value); } @@ -788,2 +788,18 @@ _cb_env_set (enum grecs_callback_command cmd, static int +_cb_env_eval (enum grecs_callback_command cmd, + grecs_node_t *node, + void *varptr, void *cb_data) +{ + grecs_locus_t *locus = &node->locus; + grecs_value_t *value = node->v.value; + struct component *comp = varptr; + + if (grecs_assert_node_value_type (cmd, node, GRECS_TYPE_STRING)) + return 1; + if (envop_entry_add (&comp->envop, envop_set, NULL, value->v.string)) + grecs_error (locus, errno, "envop_entry_add"); + return 0; +} + +static int _cb_env_unset (enum grecs_callback_command cmd, @@ -827,2 +843,8 @@ struct grecs_keyword cb_env_keywords[] = { _cb_env_set }, + { "eval", + N_("string"), + N_("Evaluate string. Useful for side-effects, e.g. eval ${X:=2}."), + grecs_type_string, GRECS_DFLT, + NULL, 0, + _cb_env_eval }, { "unset", |