| admin | create and administer SCCS files | |
| apropos | locate commands by keyword lookup | |
| ar | archive and library maintainer | |
| arcv | convert archive files from PDP-11 to VAX-11/780 format | |
| at | execute commands at a later time | |
| awk | pattern scanning and processing language | |
| banner | make posters | |
| basename | deliver portions of path names | [ basename, dirname ] |
| bc | arbitrary-precision arithmetic language | |
| bdiff | big diff | |
| bfs | big file scanner | |
| binman | print entries in this manual | [ man ] |
| bs | a compiler/interpreter for modest-sized programs | |
| cal | print calendar | |
| calendar | reminder service | |
| cat | catenate and print | |
| cb | C program beautifier | |
| cc | C compiler | |
| cd | change working directory | |
| cdc | change the delta commentary of an SCCS delta | |
| checkcw | prepare constant-width text for troff | [ cw, checkcw ] |
| chgrp | change owner or group | [ chown, chgrp ] |
| chmod | change mode | |
| chown | change owner or group | [ chown, chgrp ] |
| cmp | compare two files | |
| col | filter reverse line-feeds | |
| comb | combine SCCS deltas | |
| comm | select or reject lines common to two sorted files | |
| cp | copy, link or move files | [ cp, ln, mv ] |
| cpio | copy file archives in and out | |
| cref | make cross-reference listing | |
| crpasswd | Create password and group files | |
| crypt | encode/decode | |
| csh | a shell (command interpreter) with C-like syntax | |
| csplit | context split | |
| ctags | create a tags file | |
| cut | cut out selected fields of each line of a file | |
| cw | prepare constant-width text for troff | [ cw, checkcw ] |
| date | print and set the date | |
| dc | desk calculator | |
| dd | convert and copy a file | |
| delta | make a delta (change) to an SCCS file | |
| deroff | remove nroff/troff, tbl, and eqn constructs | |
| diff | differential file and directory comparator | |
| diff3 | 3-way differential file comparison | |
| diffmk | mark differences between files | |
| dircmp | directory comparison | |
| dirname | deliver portions of path names | [ basename, dirname ] |
| du | summarize disk usage | |
| echo | echo arguments | |
| ed | text editor | |
| egrep | search a file for a pattern | [ grep, egrep, fgrep ] |
| env | set environment for command execution | |
| eqn | format mathematical text for nroff or troff | [ eqn, neqn, checkeq ] |
| ex | text editor | [ ex, edit ] |
| expand | expand tabs to spaces, and vice versa | [ expand, unexpand ] |
| expr | evaluate arguments as an expression | |
| false | provide truth values | [ true, false ] |
| fgrep | search a file for a pattern | [ grep, egrep, fgrep ] |
| file | determine file type | |
| find | find files | |
| fmt | simple text formatter | |
| get | get a version of an SCCS file | |
| getopt | parse command options | |
| grep | search a file for a pattern | [ grep, egrep, fgrep ] |
| head | give first few lines | |
| help | ask for help | |
| hyphen | find hyphenated words | |
| id | print user and group IDs and names | |
| intro | introduction to commands | |
| join | relational database operator | |
| kill | terminate a process | |
| ld | link editor | |
| lex | generate programs for simple lexical tasks | |
| line | read one line | |
| lint | a C program verifier | |
| ln | copy, link or move files | [ cp, ln, mv ] |
| logname | get login name | |
| ls | list contents of directory | |
| m4 | macro processor | |
| mail | send mail to users or read mail | [ mail, rmail ] |
| make | maintain, update, and regenerate groups of programs | |
| man | find manual information by keywords; print out the manual | |
| mesg | permit or deny messages | |
| mkdir | make a directory | |
| mm | print out documents formatted with the MM macros | |
| more | file perusal filter for crt viewing | [ more, page ] |
| mv | copy, link or move files | [ cp, ln, mv ] |
| neqn | format mathematical text for nroff or troff | [ eqn, neqn, checkeq ] |
| news | print news items | |
| nl | line numbering filter | |
| nohup | run a command immune to hangups and quits | |
| nroff | typeset or format text | [ troff, nroff ] |
| od | octal dump | |
| oldcat | concatenate and print files | [ cat ] |
| olddiff | differential file comparator | [ diff ] |
| oldlint | a C program checker | [ lint ] |
| oldls | list contents of directories | [ ls ] |
| oldsed | stream editor | [ sed ] |
| pack | compress and expand files | [ pack, pcat, unpack ] |
| paste | merge same lines of several files or subsequent lines of one file | |
| pcat | compress and expand files | [ pack, pcat, unpack ] |
| pcc | C compiler | [ cc ] |
| pr | print files | |
| printenv | print out the environment | |
| prs | print an SCCS file | |
| ptx | permuted index | |
| pwd | working directory name | |
| ratfor | rational Fortran dialect | |
| regcmp | regular expression compile | |
| rm | remove files or directories | [ rm, rmdir ] |
| rmail | send mail to users or read mail | [ mail, rmail ] |
| rmdel | remove a delta from an SCCS file | |
| rmdir | remove files or directories | [ rm, rmdir ] |
| rsh | restricted shell (command interpreter) | |
| sact | print current SCCS file editing activity | |
| sccsdiff | compare two versions of an SCCS file | |
| sdiff | side-by-side difference program | |
| sed | stream editor | |
| sh | shell, the standard command programming language | |
| sleep | suspend execution for an interval | |
| sort | sort and/or merge files | |
| spell | find spelling errors | [ spell, spellin, spellout ] |
| spellin | find spelling errors | [ spell, spellin, spellout ] |
| spellout | find spelling errors | [ spell, spellin, spellout ] |
| split | split a file into pieces | |
| stty | set the options for a terminal | |
| sum | sum and count blocks in a file | |
| tail | deliver the last part of a file | |
| tar | tape file archiver | |
| tbl | format tables for nroff or troff | |
| tee | pipe fitting | |
| test | condition evaluation command | |
| time | time a command | |
| touch | update access and modification times of a file | |
| tr | translate characters | |
| troff | typeset or format text | [ troff, nroff ] |
| true | provide truth values | [ true, false ] |
| tsort | topological sort | |
| tty | get the terminal’s name | |
| ul | do underlining | |
| umask | set file-creation mode mask | |
| uname | print name of current UNIX | |
| unexpand | expand tabs to spaces, and vice versa | [ expand, unexpand ] |
| unget | undo a previous get of an SCCS file | |
| uniq | report repeated lines in a file | |
| units | conversion program | |
| unpack | compress and expand files | [ pack, pcat, unpack ] |
| val | validate SCCS file | |
| vi | screen oriented (visual) display editor based on ex | |
| wait | await completion of process | |
| wc | word count | |
| what | identify SCCS files | |
| whatis | describe what a command is | |
| who | who is on the system | |
| xargs | construct argument list(s) and execute command | |
| xref | cross reference for C programs | |
| yacc | yet another compiler-compiler | |
| access | determine accessibility of a file | |
| alarm | set a process’s alarm clock | |
| brk | change data segment space allocation | [ brk, sbrk ] |
| chdir | change working directory | |
| chmod | change mode of file | |
| chown | change owner and group of a file | |
| close | close a file descriptor | |
| creat | create a new file or rewrite an existing one | |
| default_acl | change default file protection environment | |
| dup | duplicate an open file descriptor | |
| exec | execute a file | [ execl, execv, execle, execve, execlp, execvp ] |
| execl | execute a file | [ execl, execv, execle, execve, execlp, execvp ] |
| execle | execute a file | [ execl, execv, execle, execve, execlp, execvp ] |
| execlp | execute a file | [ execl, execv, execle, execve, execlp, execvp ] |
| execv | execute a file | [ execl, execv, execle, execve, execlp, execvp ] |
| execve | execute a file | [ execl, execv, execle, execve, execlp, execvp ] |
| execvp | execute a file | [ execl, execv, execle, execve, execlp, execvp ] |
| exit | terminate process | |
| fcntl | file control | |
| fork | create a new process | |
| fstat | get file status | [ stat, fstat ] |
| getegid | get real user, effective user, real group, and effective group IDs | [ getuid, geteuid, getgid, getegid ] |
| geteuid | get real user, effective user, real group, and effective group IDs | [ getuid, geteuid, getgid, getegid ] |
| getgid | get real user, effective user, real group, and effective group IDs | [ getuid, geteuid, getgid, getegid ] |
| getpgrp | get process, process group, and parent process IDs | [ getpid, getpgrp, getppid ] |
| getpid | get process, process group, and parent process IDs | [ getpid, getpgrp, getppid ] |
| getppid | get process, process group, and parent process IDs | [ getpid, getpgrp, getppid ] |
| getuid | get real user, effective user, real group, and effective group IDs | [ getuid, geteuid, getgid, getegid ] |
| getwd | get current working directory | |
| intro | introduction to system calls and error numbers | |
| ioctl | control device | |
| kill | send a signal to a process or a group of processes | |
| link | link to a file | |
| lseek | move read/write file pointer | |
| mknod | make a directory, or a special or ordinary file | |
| nice | change priority of a process | |
| nice_bky | set program priority | [ nice ] |
| open | open for reading or writing | |
| pause | suspend process until signal | |
| pipe | create an interprocess channel | |
| read | read from file | |
| rename | rename a file | |
| sbrk | change data segment space allocation | [ brk, sbrk ] |
| set_sbrk_size | define memory available for allocation | |
| set_version | Sets/gets system version for syntax interpretation | [ set_version, get_version ] |
| setgid | set user and group IDs | [ setuid, setgid ] |
| setpgrp | set process group ID | |
| setuid | set user and group IDs | [ setuid, setgid ] |
| signal | catch or ignore signals | |
| soft_link | create or delete soft links | [ soft_link, soft_unlink ] |
| soft_unlink | create or delete soft links | [ soft_link, soft_unlink ] |
| stat | get file status | [ stat, fstat ] |
| time | get date and time | [ time, ftime ] |
| times | get process and child process times | |
| umask | set and get file creation mask | |
| uname | get name of current UNIX system | |
| unlink | remove directory entry | |
| ustat | get file system statistics | |
| utime | set file access and modification times | |
| wait | wait for child process to stop or terminate | |
| write | write on a file | |
| _tolower | character translation | [ toupper, tolower, toascii ] |
| _toupper | character translation | [ toupper, tolower, toascii ] |
| a64l | convert between long and base-64 ASCII | [ a64l, l64a ] |
| abort | generate an IOT fault | |
| abs | integer absolute value | |
| asctime | convert date and time to ASCII | [ ctime, localtime, gmtime, asctime, tzset ] |
| atof | convert ASCII to numbers | [ atof, atoi, atol ] |
| atoi | convert ASCII to numbers | [ atof, atoi, atol ] |
| atol | convert ASCII to numbers | [ atof, atoi, atol ] |
| bsearch | binary search | |
| calloc | main memory allocator | [ malloc, free, realloc, calloc ] |
| conv | character translation | [ toupper, tolower, toascii ] |
| crypt | DES encryption | [ crypt, setkey, encrypt ] |
| ctime | convert date and time to ASCII | [ ctime, localtime, gmtime, asctime, tzset ] |
| ctype | character classification | [ isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii ] |
| ecvt | output conversion | [ ecvt, fcvt ] |
| edata | last locations in program | [ end, etext, edata ] |
| encrypt | DES encryption | [ crypt, setkey, encrypt ] |
| end | last locations in program | [ end, etext, edata ] |
| endgrent | get group file entry | [ getgrent, getgrgid, getgrnam, setgrent, endgrent ] |
| endpwent | get password file entry | [ getpwent, getpwuid, getpwnam, setpwent, endpwent ] |
| errno | system error messages | [ perror, sys_errlist, sys_nerr, errno ] |
| etext | last locations in program | [ end, etext, edata ] |
| fcvt | output conversion | [ ecvt, fcvt ] |
| free | main memory allocator | [ malloc, free, realloc, calloc ] |
| frexp | split into mantissa and exponent | [ frexp, ldexp, modf ] |
| getenv | value for environment name | |
| getgrent | get group file entry | [ getgrent, getgrgid, getgrnam, setgrent, endgrent ] |
| getgrgid | get group file entry | [ getgrent, getgrgid, getgrnam, setgrent, endgrent ] |
| getgrnam | get group file entry | [ getgrent, getgrgid, getgrnam, setgrent, endgrent ] |
| getlogin | get login name | |
| getopt | get option letter from argv | |
| getpass | read a password | |
| getpw | get name from UID | |
| getpwent | get password file entry | [ getpwent, getpwuid, getpwnam, setpwent, endpwent ] |
| getpwnam | get password file entry | [ getpwent, getpwuid, getpwnam, setpwent, endpwent ] |
| getpwuid | get password file entry | [ getpwent, getpwuid, getpwnam, setpwent, endpwent ] |
| gmtime | convert date and time to ASCII | [ ctime, localtime, gmtime, asctime, tzset ] |
| gsignal | software signals | [ ssignal, gsignal ] |
| isalnum | character classification | [ isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii ] |
| isalpha | character classification | [ isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii ] |
| isascii | character classification | [ isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii ] |
| isatty | find name of a terminal | [ ttyname, isatty ] |
| iscntrl | character classification | [ isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii ] |
| isdigit | character classification | [ isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii ] |
| isgraph | character classification | [ isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii ] |
| islower | character classification | [ isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii ] |
| isprint | character classification | [ isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii ] |
| ispunct | character classification | [ isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii ] |
| isspace | character classification | [ isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii ] |
| isupper | character classification | [ isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii ] |
| isxdigit | character classification | [ isalpha, isupper, islower, isdigit, isxdigit, isalnum, isspace, ispunct, isprint, isgraph, iscntrl, isascii ] |
| l3tol | convert between 3-byte integers and long integers | [ l3tol, ltol3 ] |
| l64a | convert between long and base-64 ASCII | [ a64l, l64a ] |
| ldexp | split into mantissa and exponent | [ frexp, ldexp, modf ] |
| localtime | convert date and time to ASCII | [ ctime, localtime, gmtime, asctime, tzset ] |
| longjmp | non-local goto | [ setjmp, longjmp ] |
| lsearch | linear search and update | |
| ltol3 | convert between 3-byte integers and long integers | [ l3tol, ltol3 ] |
| malloc | main memory allocator | [ malloc, free, realloc, calloc ] |
| mktemp | make a unique file name | |
| modf | split into mantissa and exponent | [ frexp, ldexp, modf ] |
| monitor | prepare execution profile | |
| nlist | get entries from name list | |
| perror | system error messages | [ perror, sys_errlist, sys_nerr, errno ] |
| putpwent | write password file entry | |
| qsort | quicker sort | |
| rand | random number generator | [ rand, srand ] |
| realloc | main memory allocator | [ malloc, free, realloc, calloc ] |
| setgrent | get group file entry | [ getgrent, getgrgid, getgrnam, setgrent, endgrent ] |
| setjmp | non-local goto | [ setjmp, longjmp ] |
| setkey | DES encryption | [ crypt, setkey, encrypt ] |
| setpwent | get password file entry | [ getpwent, getpwuid, getpwnam, setpwent, endpwent ] |
| sleep | suspend execution for interval | |
| srand | random number generator | [ rand, srand ] |
| ssignal | software signals | [ ssignal, gsignal ] |
| strcat | string operations | [ strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn, strtok ] |
| strchr | string operations | [ strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn, strtok ] |
| strcmp | string operations | [ strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn, strtok ] |
| strcpy | string operations | [ strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn, strtok ] |
| strcspn | string operations | [ strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn, strtok ] |
| string | string operations | [ strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn, strtok ] |
| strlen | string operations | [ strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn, strtok ] |
| strncat | string operations | [ strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn, strtok ] |
| strncmp | string operations | [ strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn, strtok ] |
| strncpy | string operations | [ strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn, strtok ] |
| strpbrk | string operations | [ strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn, strtok ] |
| strrchr | string operations | [ strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn, strtok ] |
| strspn | string operations | [ strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn, strtok ] |
| strtok | string operations | [ strcat, strncat, strcmp, strncmp, strcpy, strncpy, strlen, strchr, strrchr, strpbrk, strspn, strcspn, strtok ] |
| swab | swap bytes | |
| sys_errlist | system error messages | [ perror, sys_errlist, sys_nerr, errno ] |
| sys_nerr | system error messages | [ perror, sys_errlist, sys_nerr, errno ] |
| toascii | character translation | [ toupper, tolower, toascii ] |
| tolower | character translation | [ toupper, tolower, toascii ] |
| toupper | character translation | [ toupper, tolower, toascii ] |
| ttyname | find name of a terminal | [ ttyname, isatty ] |
| tzset | convert date and time to ASCII | [ ctime, localtime, gmtime, asctime, tzset ] |
| acos | trigonometric functions | [ sin, cos, tan, asin, acos, atan, atan2 ] |
| asin | trigonometric functions | [ sin, cos, tan, asin, acos, atan, atan2 ] |
| atan | trigonometric functions | [ sin, cos, tan, asin, acos, atan, atan2 ] |
| atan2 | trigonometric functions | [ sin, cos, tan, asin, acos, atan, atan2 ] |
| bessel | bessel functions | [ j0, j1, jn, y0, y1, yn ] |
| ceil | absolute value, floor, ceiling, remainder functions | [ floor, fabs, ceil, fmod ] |
| cos | trigonometric functions | [ sin, cos, tan, asin, acos, atan, atan2 ] |
| cosh | hyperbolic functions | [ sinh, cosh, tanh ] |
| exp | exponential, logarithm, power, square root functions | [ exp, log, pow, sqrt ] |
| fabs | absolute value, floor, ceiling, remainder functions | [ floor, fabs, ceil, fmod ] |
| floor | absolute value, floor, ceiling, remainder functions | [ floor, fabs, ceil, fmod ] |
| fmod | absolute value, floor, ceiling, remainder functions | [ floor, fabs, ceil, fmod ] |
| gamma | log gamma function | |
| hypot | Euclidean distance | |
| j0 | bessel functions | [ j0, j1, jn, y0, y1, yn ] |
| j1 | bessel functions | [ j0, j1, jn, y0, y1, yn ] |
| jn | bessel functions | [ j0, j1, jn, y0, y1, yn ] |
| log | exponential, logarithm, power, square root functions | [ exp, log, pow, sqrt ] |
| pow | exponential, logarithm, power, square root functions | [ exp, log, pow, sqrt ] |
| sin | trigonometric functions | [ sin, cos, tan, asin, acos, atan, atan2 ] |
| sinh | hyperbolic functions | [ sinh, cosh, tanh ] |
| sqrt | exponential, logarithm, power, square root functions | [ exp, log, pow, sqrt ] |
| tan | trigonometric functions | [ sin, cos, tan, asin, acos, atan, atan2 ] |
| tanh | hyperbolic functions | [ sinh, cosh, tanh ] |
| trig | trigonometric functions | [ sin, cos, tan, asin, acos, atan, atan2 ] |
| y0 | bessel functions | [ j0, j1, jn, y0, y1, yn ] |
| y1 | bessel functions | [ j0, j1, jn, y0, y1, yn ] |
| yn | bessel functions | [ j0, j1, jn, y0, y1, yn ] |
| clearerr | stream status inquiries | [ ferror, feof, clearerr, fileno ] |
| ctermid | generate file name for terminal | |
| cuserid | character login name of the user | |
| fclose | close or flush a stream | [ fclose, fflush ] |
| fdopen | open a stream | [ fopen, freopen, fdopen ] |
| feof | stream status inquiries | [ ferror, feof, clearerr, fileno ] |
| ferror | stream status inquiries | [ ferror, feof, clearerr, fileno ] |
| fflush | close or flush a stream | [ fclose, fflush ] |
| fgetc | get character or word from stream | [ getc, getchar, fgetc, getw ] |
| fgets | get a string from a stream | [ gets, fgets ] |
| fileno | stream status inquiries | [ ferror, feof, clearerr, fileno ] |
| fopen | open a stream | [ fopen, freopen, fdopen ] |
| fprintf | output formatters | [ printf, fprintf, sprintf ] |
| fputc | put character or word on a stream | [ putc, putchar, fputc, putw ] |
| fputs | put a string on a stream | [ puts, fputs ] |
| fread | buffered binary input/output | [ fread, fwrite ] |
| freopen | open a stream | [ fopen, freopen, fdopen ] |
| fscanf | formatted input conversion | [ scanf, fscanf, sscanf ] |
| fseek | reposition a stream | [ fseek, ftell, rewind ] |
| ftell | reposition a stream | [ fseek, ftell, rewind ] |
| fwrite | buffered binary input/output | [ fread, fwrite ] |
| getc | get character or word from stream | [ getc, getchar, fgetc, getw ] |
| getchar | get character or word from stream | [ getc, getchar, fgetc, getw ] |
| gets | get a string from a stream | [ gets, fgets ] |
| getw | get character or word from stream | [ getc, getchar, fgetc, getw ] |
| pclose | initiate I/O to/from a process | [ popen, pclose ] |
| popen | initiate I/O to/from a process | [ popen, pclose ] |
| printf | output formatters | [ printf, fprintf, sprintf ] |
| putc | put character or word on a stream | [ putc, putchar, fputc, putw ] |
| putchar | put character or word on a stream | [ putc, putchar, fputc, putw ] |
| puts | put a string on a stream | [ puts, fputs ] |
| putw | put character or word on a stream | [ putc, putchar, fputc, putw ] |
| rewind | reposition a stream | [ fseek, ftell, rewind ] |
| scanf | formatted input conversion | [ scanf, fscanf, sscanf ] |
| setbuf | assign buffering to a stream | |
| sprintf | output formatters | [ printf, fprintf, sprintf ] |
| sscanf | formatted input conversion | [ scanf, fscanf, sscanf ] |
| stdio | standard buffered input/output package | |
| system | issue a shell command | |
| tmpfile | create a temporary file | |
| tmpnam | create a name for a temporary file | |
| ungetc | push character back into input stream | |