lserrno

#!/bin/bash
set -e
PROG=${0##*/}
_err() { echo -e "$PROG:" "$@" >&2 ; exit 1; }

while [ $# -gt 0 ]; do case "$1" in
  -h|-help|--help) cat << _END
List & search libc error codes along with description.
Usage: $PROG [options] [--] [<code>|<regexp>]
Options:
  -h, -help   Show help and exit
Environment variables:
  CC  Compiler to query for location of errno.h. Defaults to "cc".
Examples:
  Look up error code 4:
    $PROG 4
  List all errors containing "4":
    $PROG 4.
  List all errors related to files:
    $PROG file
  List all errors with codes in the range 20-29:
    $PROG '^ 2'
_END
    exit ;;
  --) shift; break ;;
  -*) _err "unknown option: $1" ;;
  *)  break ;;
esac; done

REGEXP=$1

descr__EPERM="Operation not permitted"
descr__ENOENT="No such file or directory"
descr__ESRCH="No such process"
descr__EINTR="Interrupted system call"
descr__EIO="Input/output error"
descr__ENXIO="No such device or address"
descr__E2BIG="Argument list too long"
descr__ENOEXEC="Exec format error"
descr__EBADF="Bad file descriptor"
descr__ECHILD="No child processes"
descr__EDEADLK="Resource deadlock avoided"
descr__ENOMEM="Cannot allocate memory"
descr__EACCES="Permission denied"
descr__EFAULT="Bad address"
descr__ENOTBLK="Block device required"
descr__EBUSY="Device or resource busy"
descr__EEXIST="File exists"
descr__EXDEV="Invalid cross-device link"
descr__ENODEV="No such device"
descr__ENOTDIR="Not a directory"
descr__EISDIR="Is a directory"
descr__EINVAL="Invalid argument"
descr__EMFILE="Too many open files"
descr__ENFILE="Too many open files in system"
descr__ENOTTY="Inappropriate ioctl for device"
descr__ETXTBSY="Text file busy"
descr__EFBIG="File too large"
descr__ENOSPC="No space left on device"
descr__ESPIPE="Illegal seek"
descr__EROFS="Read-only file system"
descr__EMLINK="Too many links"
descr__EPIPE="Broken pipe"
descr__EDOM="Numerical argument out of domain"
descr__ERANGE="Numerical result out of range"
descr__EAGAIN="Resource temporarily unavailable"
descr__EWOULDBLOCK="Operation would block"
descr__EINPROGRESS="Operation now in progress"
descr__EALREADY="Operation already in progress"
descr__ENOTSOCK="Socket operation on non-socket"
descr__EMSGSIZE="Message too long"
descr__EPROTOTYPE="Protocol wrong type for socket"
descr__ENOPROTOOPT="Protocol not available"
descr__EPROTONOSUPPORT="Protocol not supported"
descr__ESOCKTNOSUPPORT="Socket type not supported"
descr__EOPNOTSUPP="Operation not supported"
descr__EPFNOSUPPORT="Protocol family not supported"
descr__EAFNOSUPPORT="Address family not supported by protocol"
descr__EADDRINUSE="Address already in use"
descr__EADDRNOTAVAIL="Cannot assign requested address"
descr__ENETDOWN="Network is down"
descr__ENETUNREACH="Network is unreachable"
descr__ENETRESET="Network dropped connection on reset"
descr__ECONNABORTED="Software caused connection abort"
descr__ECONNRESET="Connection reset by peer"
descr__ENOBUFS="No buffer space available"
descr__EISCONN="Transport endpoint is already connected"
descr__ENOTCONN="Transport endpoint is not connected"
descr__EDESTADDRREQ="Destination address required"
descr__ESHUTDOWN="Cannot send after transport endpoint shutdown"
descr__ETOOMANYREFS="Too many references: cannot splice"
descr__ETIMEDOUT="Connection timed out"
descr__ECONNREFUSED="Connection refused"
descr__ELOOP="Too many levels of symbolic links"
descr__ENAMETOOLONG="File name too long"
descr__EHOSTDOWN="Host is down"
descr__EHOSTUNREACH="No route to host"
descr__ENOTEMPTY="Directory not empty"
descr__EPROCLIM="Too many processes"
descr__EUSERS="Too many users"
descr__EDQUOT="Disk quota exceeded"
descr__ESTALE="Stale file handle"
descr__EREMOTE="Object is remote"
descr__EBADRPC="RPC struct is bad"
descr__ERPCMISMATCH="RPC version wrong"
descr__EPROGUNAVAIL="RPC program not available"
descr__EPROGMISMATCH="RPC program version wrong"
descr__EPROCUNAVAIL="RPC bad procedure for program"
descr__ENOLCK="No locks available"
descr__EFTYPE="Inappropriate file type or format"
descr__EAUTH="Authentication error"
descr__ENEEDAUTH="Need authenticator"
descr__ENOSYS="Function not implemented"
descr__ENOTSUP="Not supported"
descr__EILSEQ="Invalid or incomplete multibyte or wide character"
descr__EBACKGROUND="Inappropriate operation for background process"
descr__EDIED="Translator died"
descr__EGREGIOUS="You really blew it this time"
descr__EIEIO="Computer bought the farm"
descr__EGRATUITOUS="Gratuitous error"
descr__EBADMSG="Bad message"
descr__EIDRM="Identifier removed"
descr__EMULTIHOP="Multihop attempted"
descr__ENODATA="No data available"
descr__ENOLINK="Link has been severed"
descr__ENOMSG="No message of desired type"
descr__ENOSR="Out of streams resources"
descr__ENOSTR="Device not a stream"
descr__EOVERFLOW="Value too large for defined data type"
descr__EPROTO="Protocol error"
descr__ETIME="Timer expired"
descr__ECANCELED="Operation canceled"
descr__EOWNERDEAD="Owner died"
descr__ENOTRECOVERABLE="State not recoverable"
descr__ERESTART="Interrupted system call should be restarted"
descr__ECHRNG="Channel number out of range"
descr__EL2NSYNC="Level 2 not synchronized"
descr__EL3HLT="Level 3 halted"
descr__EL3RST="Level 3 reset"
descr__ELNRNG="Link number out of range"
descr__EUNATCH="Protocol driver not attached"
descr__ENOCSI="No CSI structure available"
descr__EL2HLT="Level 2 halted"
descr__EBADE="Invalid exchange"
descr__EBADR="Invalid request descriptor"
descr__EXFULL="Exchange full"
descr__ENOANO="No anode"
descr__EBADRQC="Invalid request code"
descr__EBADSLT="Invalid slot"
descr__EDEADLOCK="File locking deadlock error"
descr__EBFONT="Bad font file format"
descr__ENONET="Machine is not on the network"
descr__ENOPKG="Package not installed"
descr__EADV="Advertise error"
descr__ESRMNT="Srmount error"
descr__ECOMM="Communication error on send"
descr__EDOTDOT="RFS specific error"
descr__ENOTUNIQ="Name not unique on network"
descr__EBADFD="File descriptor in bad state"
descr__EREMCHG="Remote address changed"
descr__ELIBACC="Can not access a needed shared library"
descr__ELIBBAD="Accessing a corrupted shared library"
descr__ELIBSCN=".lib section in a.out corrupted"
descr__ELIBMAX="Attempting to link in too many shared libraries"
descr__ELIBEXEC="Cannot exec a shared library directly"
descr__ESTRPIPE="Streams pipe error"
descr__EUCLEAN="Structure needs cleaning"
descr__ENOTNAM="Not a XENIX named type file"
descr__ENAVAIL="No XENIX semaphores available"
descr__EISNAM="Is a named type file"
descr__EREMOTEIO="Remote I/O error"
descr__ENOMEDIUM="No medium found"
descr__EMEDIUMTYPE="Wrong medium type"
descr__ENOKEY="Required key not available"
descr__EKEYEXPIRED="Key has expired"
descr__EKEYREVOKED="Key has been revoked"
descr__EKEYREJECTED="Key was rejected by service"
descr__ERFKILL="Operation not possible due to RF-kill"
descr__EHWPOISON="Memory page has hardware error"

MAX_NAME_LEN=15 # longest errno name

CL_CODE="\e[33;1m"
CL_ALIAS="\e[36;1m"
CL_NAME="\e[1m"
CL_RESET="\e[0m"
if ! [ -t 1 ]; then  # stdout is not a TTY; don't use ANSI codes
  CL_CODE=
  CL_ALIAS=
  CL_NAME=
  CL_RESET=
fi

FILTERCMD=(cat)
if [ $# -gt 0 ]; then
  # has filter
  if [[ "$@" =~ ^[0-9]+$ ]] ; then
    # filter is for error code
    FILTERCMD=(grep -E "^\s*$@\s")
  else
    FILTERCMD=(grep -i -E --color=auto -- "$@")
  fi
  echo "FILTERCMD ${FILTERCMD[@]}"
fi

echo '#include <errno.h>' |
  ${CC:-cc} -dM -E - |
  grep -E '^#[[:space:]]*define[[:space:]]+E' |
  cut -d' ' -f2,3 |
  while read -r name code; do
    descr=descr__$name
    [ -z "$descr" ] && ! [[ "$code" =~ ^[0-9]+$ ]] && descr=descr__$code
    printf "%3s\t%s\t%s\n" "$code" "$name" "${!descr:-"-"}"
  done |
  "${FILTERCMD[@]}" |
  while IFS=$'\t' read -r code name descr; do
    if ! [[ $code =~ ^[[:space:]]*[0-9]+$ ]] ; then
      # alias, e.g. "#define EWOULDBLOCK EAGAIN"
      printf "    ${CL_NAME}%s${CL_RESET}=${CL_NAME}%s${CL_RESET}\t%s\n" \
        "$name" "$code" "$descr"
    else
      printf "${CL_CODE}%3s${CL_RESET} ${CL_NAME}%-*s${CL_RESET}\t%s\n" \
        "$code" $MAX_NAME_LEN "$name" "$descr"
    fi
  done