diff options
| -rw-r--r-- | common/stringhelp.c | 44 | ||||
| -rw-r--r-- | common/stringhelp.h | 5 |
2 files changed, 42 insertions, 7 deletions
diff --git a/common/stringhelp.c b/common/stringhelp.c index 6959299e4..1049c78e2 100644 --- a/common/stringhelp.c +++ b/common/stringhelp.c @@ -1689,10 +1689,16 @@ format_text (const char *text_in, int target_cols, int max_cols) } -/* Substitute environment variables in STRING and return a new string. - * On error the function returns NULL. */ +/* Substitute variables in STRING and return a new string. GETVAL is + * a function which maps NAME to its value; that value is a string + * which may not change during the execution time of this function. + * If GETVAL returns NULL substitute_vars returns NULL and the caller + * may inspect ERRNO for the reason. In all other error cases this + * function also returns NULL. Caller must free the returned string. */ char * -substitute_envvars (const char *string) +substitute_vars (const char *string, + const char *(*getval)(void *cookie, const char *name), + void *cookie) { char *line, *p, *pend; const char *value; @@ -1743,19 +1749,22 @@ substitute_envvars (const char *string) { int save = *pend; *pend = 0; - value = getenv (p+2); + value = getval (cookie, p+2); *pend++ = save; } else { int save = *pend; *pend = 0; - value = getenv (p+1); + value = getval (cookie, p+1); *pend = save; } if (!value) - value = ""; + { + xfree (result); + return NULL; + } valuelen = strlen (value); if (valuelen <= pend - p) { @@ -1791,3 +1800,26 @@ substitute_envvars (const char *string) leave: return result; } + + +/* Helper for substitute_envvars. */ +static const char * +subst_getenv (void *cookie, const char *name) +{ + const char *s; + + (void)cookie; + + s = getenv (name); + return s? s : ""; +} + + +/* Substitute environment variables in STRING and return a new string. + * On error the function returns NULL. */ +char * +substitute_envvars (const char *string) +{ + return substitute_vars (string, subst_getenv, NULL); + +} diff --git a/common/stringhelp.h b/common/stringhelp.h index 915b3aa72..cd185e49a 100644 --- a/common/stringhelp.h +++ b/common/stringhelp.h @@ -169,7 +169,10 @@ int compare_version_strings (const char *my_version, const char *req_version); /* Format a string so that it fits within about TARGET_COLS columns. */ char *format_text (const char *text, int target_cols, int max_cols); -/* Substitute environmen variabales in STRING. */ +/* Substitute variables in STRING. */ +char *substitute_vars (const char *string, + const char *(*getval)(void *cookie, const char *name), + void *cookie); char *substitute_envvars (const char *string); |