Adding environment variables

diff --git a/src/input.c b/src/input.c
index d04bad902e46f3ceef0b39a87609ea12b0c96efe..9d3115f2d08c290c3fc843871b4bcddf3fa8bcc0 100644 (file)
--- a/src/input.c
+++ b/src/input.c
@@ -26,7 +26,7 @@ enum character {
    BACKSPACE = '\177',
 };
 
-static char buffer[BUFLEN + 2]; // Terminating ';'
+static char buffer[BUFLEN + 2]; // Terminating ";"
 
 char *input(void) {
    char *cursor, *end;
@@ -121,8 +121,8 @@ reset:
    fpurge(stdout);
    push(&history, buffer);
 
-   *end = ';';
-   *++end = '\0';
+   *end++ = ';';
+   *end = '\0';
 
    signal(SIGCHLD, SIG_DFL);
 

diff --git a/src/lex.c b/src/lex.c
index 08a97d4bdca25bbd45d2a72ecd5553d96ea04c5f..d032d5bdc8695ea3920c5d9b4ce3cde1100eb0a6 100644 (file)
--- a/src/lex.c
+++ b/src/lex.c
@@ -16,17 +16,21 @@ static struct cmd cmds[MAXCMDS + 1];
 struct cmd empty = {0};
 
 struct cmd *lex(char *b) {
-   char **t, *end, *p;
+   char **t, *end, *p, *env, *name, *value;
+   int e, offset;
    struct cmd *c;
    long l;
    
    if (!b) return NULL;
    t = tokens;
    c = cmds;
+   value = name = NULL;
    for (c->args = NULL, c->r = c->rds; *b; ++b) switch (*b) {
    default:
        if (!c->args) c->args = t;
-       if (!*(b - 1)) *t++ = b;
+       if (!*(b - 1)) {
+           if (!name) *t++ = b; else if (!value) value = b;
+       }
        break;
    case '<':
    case '>':
@@ -48,15 +52,27 @@ struct cmd *lex(char *b) {
        if (*(b + 1) == '&') ++b;
        break;
    case '"':
-       for (end = ++b; *end && *end != '"'; ++end) if (*end == '\\') ++end;
-       if (!*end) {
+       if (!*(b - 1)) {
+           if (!name) *t++ = b; else if (!value) value = b;
+       }
+       for (end = (p = b) + 1, b = NULL; *end; ++end) {
+           if (!b && *end == '"') b = end;
+           if (*end == '\\') ++end;
+       }
+       if (!b) {
            warnx("Open-ended quote");
            return &empty;
        }
-       *end++ = '\0';
-       *t++ = p = b;
-       b = end;
-       while (p != end) if (*p++ == '\\') {
+
+       // "..."...\0
+       // ^   ^   ^
+       // p   b   end
+       memmove(p, p + 1, end-- - p);
+       --b;
+       // ..."...\0
+       // ^  ^   ^
+       // p  b   end
+       while (p != b) if (*p++ == '\\') {
            switch (*p) {
            case 'n':
                *p = '\n';
@@ -72,15 +88,47 @@ struct cmd *lex(char *b) {
                break;
            }
            memmove(p - 1, p, end-- - p);
+           --b;
        }
+       *end = '\0';
+       memmove(p, p + 1, end - p);
+       --b;
        break;
    case '=':
+       name = *--t;
+       *b = '\0';
        break;
    case '$':
+       if (!*(b - 1)) {
+           if (!name) *t++ = b; else if (!value) value = b;
+       }
+       p = b++;
+       while (*b && *b != '$') ++b;
+       if (!*b) {
+           warnx("Open-ended environment variable");
+           return &empty;
+       }
+       *b++ = '\0';
+       for (end = b; *end; ++end);
+       // $...\0...\0
+       // ^     ^  ^
+       // p     b end
+
+       if ((env = getenv(p + 1)) == NULL) {
+           warnx("Unknown environment variable");
+           return &empty;
+       }
+       e = strlen(env);
+       offset = e - (b - p);
+       memmove(b + offset, b, end - b);
+       strncpy(p, env, e);
+       b += offset - 1;
+       *(end + offset) = '\0';
        break;
    case '&':
    case '|':
    case ';':
+       if (name && *c->args == name) c->args = NULL;
        if (c->args) {
            if ((c->term = *b) != ';' && *b == *(b + 1)) {
                ++c->term;
@@ -103,6 +151,13 @@ struct cmd *lex(char *b) {
        c->r = c->rds;
    case ' ':
        *b = '\0';
+       if (value) {
+           if (setenv(name, value, 1) == -1) {
+               warn("Unable to set environment variable");
+               return &empty;
+           }
+           value = name = NULL;
+       }
    }
 
    switch ((c - 1)->term) {