ARSC HPC Users' Newsletter Quick-Tip Index
| Select category: | All Quick-Tips | Programming | Unix | Utility | Scripting | Technical | General |
Symbol A B C D E F G H I J K L M N O P Q R S T U V W X Z
- Symbol
- .netrc fileauto-initialize ftp sessions and define ftp macros
273
- /dev/stdinaccessing stdin as a file
338
- [shell syntax for conditional tests, "/usr/bin/[" versus "/usr/bin/test" versus "[["
348
- A
- AMD Opterondetermine the core a process is using
396
- AutotoolsMakefile style advice
418
- aliasesreader favorites
146
290
363
using within scripts 342
- apportioning K tasks among M PEs
132
- arrunning ar command on 32 and 64 bit libraries on IBM systems
333
using ar or ld to combine .o files and reduce over-sized argument string 300
- argument list too longwhen the shell can't handle wildcard expansion
216
300
- assign commandtranslating unformatted files
219
- automobile engine heaterunplugging
156
- awkchecking number of inputs per line
409
examples 272 316 337 356 370 375 391 409
extracting fields from ls output 356
- B
- BLACSglobal reductions with BLACS, coding from communication primitives
351
- babelconnecting C/C++ to python
344
- base conversionconverting numbers between bases in Unix
282
- basename/dirname commandsreturn file name or directory path from a path/filename string
268
- bashcommand completion in bash
353
command line editing 397
extracting the extension from a filename using pattern matching operators 347
- batchsubmitting batch jobs in IRIX
249
- batch removeusing Unix commands
179
- bcevaluating math expressions found in a text file
285
406
- bearsdefense against
197
- blankets on your carwarming your car when it's cold out
334
- blind directoriessafer file sharing
191
- book reviewscientific books
320
- bucket sortfaster than quicksort
141
- C
- CC vs Fortran -- default array indexing
154
155
calling C from Fortran -- portable interface 260
comment blocks for documentation systems 367
commenting out commented code, or, how to nest "comments" 339
finding path of an executable 183
linking gridinfo, gridinit, and FFT libraries with C/C++ code 233
path to executable 183
pointer pointer 394
pointer reference 159 394
preprocessor directives with make 326
pretty-printer 295
programming style question, how would you choose the minimum 264
question-mark colon construct 127
retaining the precision of output doubles using format specifiers 361
trapping floating point errors using gcc feenableexcept 376
using realloc 394
viewing arrays in totalview 145
- C++confusion between "cpp" and "CC" commands
279
copying values from a C style array to a STL vector 350
linking to C libraries 308
using the STL map class 399
using the STL vector assign member function 350
using the STL vector reserve member function 350
using the stringstream class 373
- C/C++calling from python
344
349
- CDPATHjumping between directories
123
- CPUdetermine the core a process is using
396
- CVSalternative to diff
313
version control and software maintenance 278
- Catch-22
257
- Co-Array Fortranarray bounds
154
- Collectivescollective nouns for supercomputer related terminology
384
- Compiler options-O3,aggress
166
-g 166
from the executable file, determine what compiler flags were used 368
- Cray Fortran(/ ... /) syntax -- array constructor
157
-Fmacro expansion 174
-Oinlinefrom 207
-Rbarray bounds checking 129
-Vversion 149
-eIimplicit none 129
-rxreport on variable usage and cross-references 221
-s cf77typestype compatibility with Fortran 77 174
-static 202
ALLOCATE statement -- testing for success 135
Directive for unwinding loops 292
performance comparison of DO-IF vs WHERE 205
- cURLcommand-line retrieval of web pages
311
- carpal tunnel syndromeavoiding
113
- chgrp
192
- chmod-R go+rXintelligently add execute bit
147
1770setting the sticky bit 109
changing entire path to a selected file, but not recursively 220
g=x ~blind home directory 191
group/world executable directories put at risk all files within 298
- code-blindnesscures
271
- col-bxconverting man pages
118
- commusing the comm command to compare files
362
- commasreformatting long number strings with comma separators
329
- compilersdetermining version
149
- core filesdeterminine origin of
200
limiting size 121
managing files from many processes 403
- cp--parentspreserving parent directories (GNU cp)
377
-i 187
-pcopying modification time along with the file 231
- cpuUNICOS /etc/cpu command for control over caching
209
- cshfile name completion
176
redirecting stderr and stdout 223
- csh/tcshcommand line editing
397
extracting the extension from a filename using variable modifiers 347
- cutextracting columns of data from text files
272
337
356
- D
- DISPLAY environment variableIncorrect setting causes console session failure
243
- DMFFile compression and affect on DMF migration
188
How to dmput files owned by other members of a group 222
- DoxygenFor code documentation
367
- DuplicatesFinding duplicate files
392
- date+%Y%m%dCreating file versions with a date stamp
310
--dateTiming a series of jobs 393
Generating a series of file names containing dates 398
- date stampCreating file versions with a date stamp
310
- dcdesktop calculator
167
- debuggingfinding problem in one of many source files
275
- deleting ^M characters in batch
139
287
- deleting the file "-i"
102
- development environmentsreader favorites
341
- diamond as conductor
120
- diff"modern" alternatives to diff (tkdiff, ediff, vimdiff, etc...)
313
-D 124
comparing a file to stdin 338
comparing a remote file to a local file 338
ndiff, numerical differences allowed and handled intelligently 378
- dirname/basename commandsreturns directory path or file name from a path/filename string
268
401
- dmgetmost efficient use
162
- dotfilesmaintaining consistent dotfiles across multiple systems
312
- du-minclude Cray DMF migrated files
164
-skexcludes Cray DMF migrated files, under-estimates size of tar file 267
-sktotaled disk usage in KBs 164
-sktotal size of subdirectories 405
- E
- e-mailsending automatic vacation messages
143
- e-mail from NQS
138
- echofor shell preview of wild-card expansion
256
in .bashrc causes scp failure 419
- editorsfavorite development environments
341
using text editors to copy/paste rectangular blocks 272
- egrepadvanced filtering examples
161
168
337
389
- emacsdiff-like features
313
getting colors to work on any platforms 297
tramp to access remote files 314
- env/usr/bin/env searches PATH for binary
372
- environment variablesappending to $PATH, $LM_LICENSE_FILE, etc.
245
available to running NQS jobs 198
show environment of a running process 417
testing if set 319
- escapescontrolling the interpretation of regular expressions
280
- evalevaluate variable as a perl program
406
- exsingle command line "ex" command prepends file A to file B
302
- execUnix exec command, for redirecting stdout to file for entire session
388
- exit statusof a pipeline
412
- expand commandreplacing tabs with spaces
203
- expectan expect script for ftp initialization
273
timeout 411
- explainCray's "explain" command prints details on many warnings/errors
293
- exprdifferences
237
using regular expression to extract a substring 347
- eye strainreducing
106
- F
- FFTlinking gridinfo, gridinit, and FFT libraries with C/C++ code
233
- FortranCYCLE and EXIT
248
249
DO loop iterator exit value, formula for computing 325
Fortran 90 INTEGER constants 215
Fortran 90 MODULE replaces Fortran 77 COMMON 199
Fortran 90 OPTIONAL subroutine args and effect on inlining 208
Fortran 90 generic functions 215
Fortran vs C -- default array indexing 154 155
IO buffering problems caused out-of-order output, fixed with flush 386
LOG10 vs ALOG10 158
NAMELIST 213
OPEN (RECL=1024) 144
RESHAPE 228
WRITE 144
WRITE with implied DO incompatible with read with explicit DO 284
calling C from Fortran -- portable interface 260
calling from Python 421
f90 type inconsistency 174
free vs fixed format discussion 261
header and include files 171
intrinsic functions 158
pretty-printer 295
trapping floating point errors using gcc feenableexcept 376
unformatted files and porting them 219
using arbitrary array bounds 154 155
- file commandprobe file type and other info
112
200
332
- filesaccess time
178
batch editing in place 126
compression and its affect on DMF migration 188
determining source or type of 112
generating unique file names in C/C++/Fortran programs 229
remote access 402
sharing with your group without compromising home directory 191
- find-ctimeto find recently changed files
405
-execusing with grep 283
-execusing with tar 331
-exec and -typeusing -exec with chmod and -type 332
-mminto find recently modified files (GNU find) 346
-mtimeto find recently modified files 346
-pruneprevent descending into subdirectory 181 187
-sizefinding large files to help stay under quota 259
-type mfinding migrated files 162
examples 147 187 230 283 331 332 357 405
preserving files which match a wildcard expression, deleting the rest 301
removing core and mppcore files 107
- ftpautomating ftp sessions with batch scripts and initialization macdef macros
273
how to "more" remote and local files 105
mget/mput a batch of files without prompting 277
- G
- gccinline assembly
396
- gdbstack traces from many files
403
- grep--signifies end of options
226
-llisting file names 103
-oShow only the part of a matching line that matches the pattern 358
-vexcluding grep itself from ps output 224
list files not containing certain text, using find -exec 230
list lines before search pattern 345
listing file names even when only one file searched 283
searching for multi-line patterns 371
- grmview-deqdetermining memory usage at runtime
134
-l 134
- groupgroup/world executable directories put at risk all files within
298
what determines group ownership of a new file 192
- gzipDetermining if a zipped file is okay without unzipping it
321
- H
- Haskellexamples
375
410
- hexidecimalconverting decimal to hex and back in Unix
282
- hidden characters in file names
180
- I
- ImageMagick for postscript to png image conversion
374
- Initializing program parametersavoiding recompilation
213
- implicit none
129
adding implicit none and explicit declarations to legacy codes 221
- inliningimpeded by Fortran 90 OPTIONAL arguments and one workaround
208
inlinefrom required by Cray Fortran if source in separate files 207
- interprocess communicationcommunicating Perl processes
407
- J
- jajob accounting command
190
- K
- kdestroyremoving Kerberos tickets
288
- kerberoskerberos skew too great
189
next token mode 169
- keyboard keys"enlarging" a too-small key on the keyboard by remapping it
352
- killaborting MPP jobs
125
- krcpcopying directories recursively
343
- ksh"_" environment variable
183
CDPATH environment variable 123
PS1, favorite settings for your shell prompt 349
command line editing 397
file name completion 176
history file environment variable, HISTFILE 317
integer keyword 354
loops in ksh 354 370
prompt, favorite settings for your shell prompt 349
redirecting stderr and stdout 223
typeset declaration 385
- L
- Linuxcommands for beginners
408
- Loadlevelergetting number of nodes and procs
316
- ldusing ld or ar to combine .o files and reduce over-sized argument string
300
- librariesdetermining which used
168
show which shared library each symbol in an executable is provided by 383
- limit-d dlimlimiting size of core files
121
setting maximum stack frame size when your code won't compile 202
- listserverproblems unsubscribing
218
- llsubmitstarting batch job in directory from which it was submitted
289
- ln-spreventing core file creation
114
- lock filecommunicating Perl processes
407
- ls-Ssort by file size
405
-boctal codes for nongraphic characters 180
-dlisting directories only 391
-qquestion marks for nongraphic characters 180
-tsort by last time file was modified 405
-usort by last time file was accessed 405
colorized output 415
when directory is not "executable" 244
- ls *listing two subdirectory levels
128
- lslppgetting XLF version numbers
318
- M
- MFLOP/Smeasuring on T3E
153
- MPIMPI_Abort for aborting MPP jobs
125
MPI_Bcast vs SHMEM_BROADCAST 195
MPI_Comm_dup and creating your own MPI libraries 232
MPI_Rsend, synchronizing with MPI_Recv 291
displaying system information from an MPI program 399
how to preface stdout with task number 255
message tags, coordinating sends and recvs 210
using PMPI to build custom MPI subroutine timers 382
- MPI compilershow the flags the MPI compiler passes to the system compiler
390
- Minneapolisbest restaurants
170
- make.PHONY target
400
Makefile style advice 418
dependency for Makefile itself 111
parallel 148
passing macro definitions from "make" compile line through to compilers 297
preprocessor directives with make 326
unconditional make 400
- man pagesadding personal man pages to search path
186
stripping format chars 118
- md5sumusing to find duplicate files
392
- memorizationhow to remember numbers
305
- memory for T3E compilergetting (or not) more of it
251
- memory utilizationdetermining at run-time with ja command
190
- merging source code versions
124
- mkdir-pmaking complete tree
172
- modules (Fortran 90)initializing variables
199
- modules (UNICOS environment)"module load pghpf" command
151
creating custom Cray Programming Environment modules 186
listing compilers, libs, tools, etc. and versions 117
trouble calling "module" in qsub script 206
- mosquitosrepellents, traps, and head nets
250
- mpirun-ffor complex argument lists
211
timing a series of mpirun commands to evaluate performance changes 393
- mpixx, mpicc, mpixlf90show the flags the MPI compiler passes to the system compiler
390
- mppcore filesdeleting
107
storing on /tmp 114
- mppsize command
112
- mppview-tdetermining memory usage at runtime
134
- mppwidthfetching core count within a job
404
- mv-i
187
moving a directory into itself 225
pitfalls 177
- N
- NQS daemon
175
- NQS jobautomatically creating unique directory for output
269
checking stdout/stderr while still running 217
determining if checkpointed 140
preventing rerun 119
vanishes 138
- NetCDFnetCDF Operators (NCO)
378
testing the equivalence of netCDF files while allowing for differences in precision 378
viewing netCDF data 327 378
- New Years Computing Resolutions
236
- ndiffdiff of files, but with numerical differences allowed and handled intelligently
378
- nmshow which shared library each symbol in an executable is provided by
383
- numeric constantsdeclaring in Fortran 90 to be of a particular type
215
- numerical precisionnumerical precision and roundoff error summing real numbers
366
- O
- OBJECT_MODErunning ar command on 32 and 64 bit libraries on IBM systems
333
- OS version numberdiscover using "uname" command
204
- OpenMPPermissible C/C++ "for" loops
253
SINGLE vs MASTER comparison 212
- od-cviewing files
180
287
337
-tdisplay binary data converted to standard types 365
- optimization level defaultsCray, SGI, IBM compilers
235
- P
- PATT3E performance analysis tools
153
- PATHlisting one path per line in a colon-delimited list of paths
265
- PBSscript generation
395
testing if PBS_O_WORKDIR set 319
- PEvers (programming environment components)
117
- PIPESTATUScapture pipeline exit status
412
- Pigetting machine precision value for Pi in C/C++ and Fortran programs
263
- parallel make
148
- parallel random number generation
133
- passwordsinvent and remember
131
remembering 324
- pathhow-compiledPathscale compiler option to determine, from the executable, what compiler flags were used
368
- performance improvementgeneral advice
166
timing a series of MPI jobs 393
- perl".." (ranging operator) many nifty uses
163
-eentering script on command line 163 265
-p -iedit files in-place, assumed loop 126 208 274 304
Algorithm::Permute module 410
File::Basename module 401
FindBin module 401
Schwartzian transform 375
Time::Local module 398
alarm 411
checking number of inputs per line 409
evaluating math expressions found in a text file, and s///e 285
examples 241 262 265 287 304 322 329 356 357 358 370 375 409
extracting fields from ls output 356
map 358
recovering from an untar in the wrong place 357
script for condensing a file 116
slurp mode 371
- perl regular expressionslook-ahead assertion
358
minimal, or non-greedy, matching 262 358
- perl xdumpread binary files and convert
365
- permissionssetting for a directory tree
416
- pghpfaccessing man pages
151
- pgreplist processes that meet criteria
407
- pipefailcapture pipeline failure status
412
- postscript to png image conversionImageMagick, gs, gimp, Netpbm, pstopnm, and ps2png
374
- preprocessingcpp examples
260
339
- program memory usagehow to determine
134
137
- ps-e option to show environment of a process
417
-p $$to determine which shell I'm using 294
extracting grep process from grepped output 224
- python"/usr/bin/env python" searches PATH for python binary
372
calling C/C++ from 344 349
calling Fortran from 421
evaluating math expressions found in a text file 285
examples 375 392
extracting matched patterns from lines of input 358
glob module 385
itertools module 410
os.path.walk 392
set type in python 362
- Q
- qalteraltering NQS requests at run-time
150
- qdeldeleting a list of jobs
381
- qsub-jjob log
140
-l mpp_tMPP time 136
-l p_mpp_tMPP time per process 136
-nrno restart 119
-rocheck stdout while job still running 217
chaining a sequence of jobs 150
specifying shell to use 206
starting batch job in directory from which it was submitted 198
- quotahow to locate all your big files so you can move or delete them
259
- quotescontrolling the interpretation of regular expressions
280
- R
- readexample of shell read construct
356
- redirecting stdoutUnix exec command, for redirecting stdout to file for entire session
388
- remap keyboard"enlarging" a too-small key on the keyboard by remapping it
352
- renamerenaming files
322
385
- resetcommand for rescuing corrupted terminal session
361
- rm-i and -fusing together
270
deleting a file named "-i" 102
disabling "rm *" (while otherwise allowing "*") 355 356
preserving files which match a wildcard expression, deleting the rest 179 301
- rmdir-pdeleting directory tree
172
- roundoff errornumerical precision and roundoff error summing real numbers
366
- rsynccheck for differences in a remote file
413
preserve file ownership and group settings during file transfer 364
- rubypermutation library
410
- S
- SHMEMSHMEM_BROADCAST vs MPI_Bcast
195
shmem_fence vs shmem_quiet 194
- SV1disabling caching
209
- SWIGconnecting C/C++ to python
344
349
- SecurID Cardgenerating a sequence of valid codes w/out reentering PIN
196
handling & storing 160
obtainin a new PIN 201
- Sourdough Sam Math contest
165
- Stack frame size too largeSGI f90 warning
202
- scp-pto preserve dates during transfer
314
copying directories recursively 343
echo command in .bashrc causes failure 419
using remote environments with scp 340
- scurvy, avoidingTips for impoverished students
369
- search and replaceas smart as you want, across many directories and files
208
removing unwanted octal and extended ASCII codes from text files 287
- sedexamples
139
216
241
283
290
304
315
322
323
329
349
search replace on slew of files 304
- sequsing seq to generate a range of dates
398
using seq with ksh 354
- shellappending to the settings of existing environment variables, like PATH
245
command line editing 397
expansion of wildcard characters 216 225 256
how to determine which shell I'm using 294
prompt and PS1, favorite settings for your shell prompt 349
sh script to reformatting number strings with commas 329
shell aliases -- reader favorites 146
syntax for conditional tests, "[" versus "[[" versus "test" 348
- sort-nnumeric sort
405
Unix sort examples 281 316 337 389
- sort methods compared
141
- sortingsorting when the key field can be pattern matched, but isn't normally delimited
375
sorting words on one line 152
- squeezing text
116
- ssh-c arcfourfaster, but less secure, transfers
414
known_hosts file 402
piping input/output to/from 414
searching a list of machines 402
using a ssh configuration file to create machine aliases 353
- statdetailed inode listins
356
- static memory allocationdetermining
137
- stderrpiping both stderr and stdout with csh and ksh
335
- sticky bit
109
- stringsUnix command
168
- stty erase <BACKSPACE>
110
- T
- table of squaresusing recurrence to compute quickly
286
- tabsreplacing with spaces
203
- taradding selected files only
377
archiving specific files only 331
extracting specific files only 323
moving everything accidentally untarred in the wrong directory somewhere else 357
piping input/output to/from 414
relative untar (remove leading "/'s") 184
transferring directories between systems using tar with stdin and stdout 343
using tar to preserve file ownership and group settings during file transfer 364
why is tar file 3x expected size from "du -sk" 267
- tcshcommand completion in tcsh
353
command line editing 397
disabling "rm *" with "set rmstar=1" 355
- teepiping stderr and stdout to a file and displaying on the screen
335
- terminalcolorized output
415
- testshell syntax for conditional tests, "/usr/bin/[" versus "/usr/bin/test" versus "[["
348
- tips for lifefrom readers
185
306
warming your car when it's cold 334
- tips for studentsmilk crates
369
paying bills 369
- tmp and scratch purgers
177
- totalviewexpanding fortran automatic arrays
243
viewing C arrays 145
- touch-rcopying file access and mod time
231
- trtranslate command, example
140
152
316
337
356
375
- U
- Unixfinding path of an executable
183
path to parent script 401
- Unix commandsLinux commands for beginners
408
giving arguments that start with "-" and could be construed as options 226
- Unix vacation programautomatic e-mail reply
143
- ualsextracting fields from ls output
356
finding files newer than a specified age 377
- ulimit-tset a hard limit on CPU time
411
- ulpWhat's an ulp? Or, Unit of Least Precision
254
- unameprint system info (hostname nodename release version hardware)
204
- uniqUnix uniq command, examples
316
362
- unique directory namegenerating automatically in scripts
269
- V
- version controlmaintaining software in collaborations
278
- vi"!" and ":" commands, how to use registers to edit, save, and execute again
173
379
"yank" from file 1 and "put" into file 2 252
"|" jump to column 115
:%s,/lib ,/usr/lib ,using characters other than "/" to delimit search/replace 266
:%s/^M//gremoving CTRL-M characters 139
:.,'m s/^/Ccommenting-out blocks of Fortran code 104
:10,30s/.\{25\}/&|/inserting vertical lines 142
:frenaming file buffer 193
:rusing file insertion to prepend a file to current file 302
ex commands 104 302 379
finding cursor column 115
generating and loading a list of files from grep 103
noautoindentfixing staggering paste 122
regular expresion to switch order of element within a line 274
- vim"&" repeats last ":s" command
379
autocmd, remember cursor position and other state between sessions 336
making color schemes 328
register ":" contains last ":" (or ex) command. "@:" executes it again 379
replace 330
setting highlight colors 328
- vimdiffcheck for differences in remote file
413
- W
- WHERE construct in Fortran 90
205
- web browsersobtaining URL of a frame in Netscape, IE, Lynx
227
- wgetcommand-line retrieval of web pages
311
- what commandprobing executable
108
168
- X
- xargs-lusing with find and grep
283
examples 283 301 304 322
preserving files which match a wildcard expression, deleting the rest 301
- xlf-qreport -qlistloop, optimization, and other listings
309
-qsuffixIBM Fortran compiler, recognizing .f90 files as Fortran 90 246 303
-qsuffixRunning the preprocessor on files with arbitrary suffix 303
getting XLF version numbers 318
- Z
- zshcommand completion in zsh
353
command line editing 397
disabling "rm *" 355
loops in zsh 354
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