ref: 556618eb07d1ac6e2c629a60acd53c45d53261be
dir: /sys/src/cmd/upas/imap4d/csquery.c/
#include <u.h> #include <libc.h> /* * query the connection server */ char* csquery(char *attr, char *val, char *rattr) { char token[64 + 4], buf[256], *p, *sp; int fd, n; if(val == nil || val[0] == 0) return nil; fd = open("/net/cs", ORDWR); if(fd < 0) return nil; fprint(fd, "!%s=%s", attr, val); seek(fd, 0, 0); snprint(token, sizeof token, "%s=", rattr); for(;;){ n = read(fd, buf, sizeof buf - 1); if(n <= 0) break; buf[n] = 0; p = strstr(buf, token); if(p != nil && (p == buf || p[-1] == 0)){ close(fd); sp = strchr(p, ' '); if(sp) *sp = 0; p = strchr(p, '='); if(p == nil) return nil; return strdup(p + 1); } } close(fd); return nil; }