From 11fac6778ba2b4fb584262ea798acf9a8b3bb86f Mon Sep 17 00:00:00 2001 From: gad Date: Tue, 21 Jun 2005 21:37:53 +0000 Subject: Fix a bug where the value of ${SOMEVAR} would simply disappear if there was a separator character immediately before it. This wasn't likely to happen in #-lines, but we might as well get it right. Also fix it so that "" and "" will create a zero-length argument. Approved by: re (blanket `env') --- usr.bin/env/envopts.c | 71 ++++++++++++++++++++++++++++++++++----------------- 1 file changed, 48 insertions(+), 23 deletions(-) diff --git a/usr.bin/env/envopts.c b/usr.bin/env/envopts.c index 66e80f6..cf85b1f 100644 --- a/usr.bin/env/envopts.c +++ b/usr.bin/env/envopts.c @@ -43,8 +43,9 @@ __FBSDID("$FreeBSD$"); #include "envopts.h" -static void expand_vars(char **thisarg_p, char **dest_p, const char - **src_p); +static const char * + expand_vars(char **thisarg_p, char **dest_p, const char + **src_p); static int is_there(char *candidate); /* @@ -161,7 +162,8 @@ search_paths(char *path, char **argv) void split_spaces(const char *str, int *origind, int *origc, char ***origv) { - const char *bq_src, *src; + static const char *nullarg = ""; + const char *bq_src, *copystr, *src; char *dest, **newargv, *newstr, **nextarg, **oldarg; int addcount, bq_destlen, copychar, found_sep, in_arg, in_dq, in_sq; @@ -190,7 +192,14 @@ split_spaces(const char *str, int *origind, int *origc, char ***origv) bq_destlen = in_arg = in_dq = in_sq = 0; bq_src = NULL; for (src = str, dest = newstr; *src != '\0'; src++) { + /* + * This switch will look at a character in *src, and decide + * what should be copied to *dest. It only decides what + * character(s) to copy, it should not modify *dest. In some + * cases, it will look at multiple characters from *src. + */ copychar = found_sep = 0; + copystr = NULL; switch (*src) { case '"': if (in_sq) @@ -198,6 +207,12 @@ split_spaces(const char *str, int *origind, int *origc, char ***origv) else if (in_dq) in_dq = 0; else { + /* + * Referencing nullarg ensures that a new + * argument is created, even if this quoted + * string ends up with zero characters. + */ + copystr = nullarg; in_dq = 1; bq_destlen = dest - *(nextarg - 1); bq_src = src; @@ -207,7 +222,8 @@ split_spaces(const char *str, int *origind, int *origc, char ***origv) if (in_sq) copychar = *src; else { - expand_vars((nextarg - 1), &dest, &src); + copystr = expand_vars((nextarg - 1), &dest, + &src); } break; case '\'': @@ -216,6 +232,12 @@ split_spaces(const char *str, int *origind, int *origc, char ***origv) else if (in_sq) in_sq = 0; else { + /* + * Referencing nullarg ensures that a new + * argument is created, even if this quoted + * string ends up with zero characters. + */ + copystr = nullarg; in_sq = 1; bq_destlen = dest - *(nextarg - 1); bq_src = src; @@ -305,14 +327,22 @@ split_spaces(const char *str, int *origind, int *origc, char ***origv) copychar = *src; } } - if (copychar) { + /* + * Now that the switch has determined what (if anything) + * needs to be copied, copy whatever that is to *dest. + */ + if (copychar || copystr != NULL) { if (!in_arg) { /* This is the first byte of a new argument */ *nextarg++ = dest; addcount++; in_arg = 1; } - *dest++ = (char)copychar; + if (copychar) + *dest++ = (char)copychar; + else if (copystr != NULL) + while (*copystr != '\0') + *dest++ = *copystr++; } else if (found_sep) { *dest++ = '\0'; while (isspacech(*src)) @@ -355,11 +385,11 @@ str_done: * at the initial '$', and if successful it will update *src_p, *dest_p, and * possibly *thisarg_p in the calling routine. */ -void +static const char * expand_vars(char **thisarg_p, char **dest_p, const char **src_p) { const char *vbegin, *vend, *vvalue; - char *edest, *newstr, *vname; + char *newstr, *vname; int bad_reference; size_t namelen, newlen; @@ -393,7 +423,7 @@ expand_vars(char **thisarg_p, char **dest_p, const char **src_p) fprintf(stderr, "#env replacing ${%s} with null string\n", vname); - return; + return (NULL); } if (env_verbosity > 2) @@ -402,29 +432,24 @@ expand_vars(char **thisarg_p, char **dest_p, const char **src_p) /* * There is some value to copy to the destination. If the value is - * shorter than the ${VARNAME} reference that it replaces, then we - * can just copy the value to the existing destination. + * shorter than the ${VARNAME} reference that it replaces, then our + * caller can just copy the value to the existing destination. */ - edest = *dest_p; - if (strlen(vname) + 3 >= strlen(vvalue)) { - while (*vvalue != '\0') - *edest++ = *vvalue++; - *dest_p = edest; - return; - } + if (strlen(vname) + 3 >= strlen(vvalue)) + return (vvalue); /* * The value is longer than the string it replaces, which means the * present destination area is too small to hold it. Create a new - * destination area, copy the present 'thisarg' value and the value - * of the referenced-variable to it, and then update the caller's - * 'thisarg' and 'dest' variables to match. + * destination area, copy the present 'thisarg' value to it, and + * update the caller's 'thisarg' and 'dest' variables to match. + * Note that it is still the caller which will copy vvalue to *dest. */ - *edest = '\0'; /* Provide terminator for 'thisarg' */ + **dest_p = '\0'; /* Provide terminator for 'thisarg' */ newlen = strlen(*thisarg_p) + strlen(vvalue) + strlen(*src_p) + 1; newstr = malloc(newlen); strcpy(newstr, *thisarg_p); - strcat(newstr, vvalue); *thisarg_p = newstr; *dest_p = strchr(newstr, '\0'); + return (vvalue); } -- cgit v1.1