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Hi Artem, If it segfaults in a supported function then it will be fixed. As for what extent support is provided, I did just enough to get the basix Unix utilities to work (e.g., ls et. al.). Putting in more proved to be a big hassle and just wasn't called for in the context of what we were trying to do (i.s., get the regular HEP apps to work). Andy On Thu, 28 Jan 2010, Artem Trunov wrote: > Hi, Andy! > > > > On Wed, Jan 27, 2010 at 10:33 AM, Andrew Hanushevsky > <[log in to unmask]>wrote: > >> Hi Artem, >> >> Actually, the preload library provides support for the basic stdio >> functions (e.g., fopen()). So, basic programs should work. > > > Hm.. I made a little program that just reads few bytes from a file, then > writes this to another file, so it uses only fopen,fread,fwrite,fclose. It > works fine on the local fs, but seg faults on the xrootd VMP in fread. > > FILE *fp; > float d[1]; > fp = fopen(fname, "r"); > fread( d, sizeof( float ), 1, fp ); > > (gdb) backtrace > #0 0x00000036a8e68880 in fileno_unlocked () from /lib64/libc.so.6 > #1 0x00002b0fc94509d7 in XrdPosix_Fread (ptr=0x7fff7e8b89f0, size=4, > nitems=1, stream=0x0) at XrdPosix.cc:465 > #2 0x00002b0fc945c7c5 in fread (ptr=0x7fff7e8b89f0, size=4, nitems=1, > stream=0x0) at XrdPosixPreload.cc:205 > #3 0x00000000004006c9 in main () > > So, seems like fread is cought by the preload library, but something doesn't > work out. Any ideas? > > Full support is not provided because, frankly, the stdio package is not >> ideal for programming high performance applications. For instance, many >> platform restrict the number of open files to 256 when you use stdio; which >> is very limiting. > > > To what extent is support provided? > > >> I know stdio is much like editors (you love what ou first get to know) but >> I would discourage using the fxxx() functions in general. >> > > Well, some apps are just written that way... > > cheers > Artem. >